JP6418756B2 - Method for producing aluminum alloy conductor and method for producing electric wire using aluminum alloy conductor - Google Patents

Description

The present invention is used for the wiring under under drive environment or vibration conditions such as vibration and bending, tensile strength, bending resistance, and using the manufacturing method and aluminum alloy conductor of good aluminum alloy conductor wire drawability Regarding electric wires.

Aluminum is promising as a conductive material to replace pure copper because it is lightweight, highly conductive, and inexpensive. However, since aluminum has a lower tensile strength than pure copper, it cannot be used for industrial robot cables, for example, wire drawing to form a conductor wire having a wire diameter of 100 μm or less with high efficiency. Have the problem. Moreover, the current aluminum-based alloy does not have the bending resistance required for industrial robot cables, for example, the bending resistance that can withstand dynamic driving (repeated bending) of 1 million times or more. Therefore, the metal structure of the aluminum-based alloy is refined, for example, the average grain size of the crystal grains constituting the metal structure is set to 2 μm or less, and the crystal grains having a grain size of 1 μm or less are included in a cross-sectional area ratio of 20% or more. At the same time, a bend-resistant conductive material that guarantees a dynamic drive of 1,000,000 times by dispersing nanoparticles of β double prime phase having a particle size of 10 to 80 nm has been proposed (for example, see Patent Document 1). ).

WO2013 / 002272 Publication

The bending-resistant conductive material of Patent Document 1 has improved tensile strength and breaking tensile elongation by refining the metal structure, thereby improving wire drawing workability. However, when the application of a long-span machine device cable, etc. is assumed for this bending-resistant conductive material, the tensile strength of this bending-resistant conductive material is insufficient for the self-weight tension generated in the cable. There is a problem that a cable made of this bending-resistant conductive material cannot be used alone.

Furthermore, in order to stably operate an industrial robot for a long period of time, there is a problem that the bending resistance that guarantees a dynamic drive of 1 million times is insufficient. Therefore, by orienting the crystal grains constituting the metallographic structure in the wire drawing direction and increasing the amount of nanoparticles dispersed, the fatigue crack growth rate can be reduced and the bending resistance can be improved. Has been done. However, in the metal structure of the bending-resistant conductive material of Patent Document 1, since the degree of miniaturization is low, a sufficient equiaxed crystal structure cannot be formed, and the orientation of the crystal grains during the wire drawing process is reduced. It is difficult to control sufficiently. In order to increase the dispersion amount of nanoparticles, it is necessary to increase the addition amount of the nanoparticle-forming elements. However, since some of the added nanoparticle-forming elements are dissolved in the aluminum crystal grains, As the solid solution amount of the particle forming element increases, the conductivity of the crystal grains decreases and the conductivity of the produced conductor wire also decreases. Furthermore, when the amount of the nanoparticle-forming element added is increased, the frequency with which precipitates having a large particle size are formed from the nanoparticle-forming elements is improved, and the precipitate becomes a defect and the wire is formed during wire drawing. The problem of disconnection arises.

The present invention has been made in view of such circumstances, and has high tensile strength, high bending resistance, and high wire drawing workability while maintaining the light weight and high conductivity of aluminum, such as vibration and bending. and to provide a method for manufacturing a wire using the manufacturing method and aluminum alloy conductor of the aluminum alloy conductor that can be used for wiring under drive environment or vibration state.

The method for producing an aluminum alloy conductor according to the first invention in accordance with the above object is a method for producing an aluminum alloy conductor that is commonly used in a vibration or bending drive environment or vibration state,
An intermetallic compound is formed with aluminum, and the addition amount to aluminum has a reaction composition in which an eutectic reaction or a peritectic reaction occurs in a region of 5% by mass or less (that is, a eutectic point or a peritectic point); Further, an aluminum casting containing 0.3% by mass or more and 5% by mass or less of element X (with respect to aluminum) whose solid solution limit in aluminum is less than the above reaction composition is subjected to strong processing having a total equivalent strain of 100 or more. As the cast structure of the aluminum casting is refined, the aluminum fine crystal grains, the first nanoparticles made of the intermetallic compound present in the aluminum fine crystal grains, and the aluminum fine crystals Forming a nanoparticle-dispersed structure having the second nanoparticle composed of the intermetallic compound present in the grain boundary of the grains ,
1) The aluminum fine crystal grains have a particle size of 800 nm or less, the first and second nanoparticles have a particle size of 500 nm or less, and the tensile strength at the time of a tensile test at room temperature is 220 MPa or more and is repeatedly bent at room temperature. The number of breaks in the test is 3 million times or more, and the electrical conductivity at room temperature is 50% IACS or more.
2) The aluminum casting is heat-treated at a temperature of 300 ° C. or less before or during the strong processing, or
3) The aluminum alloy conductor is heat-treated at a temperature of 300 ° C. or lower .
Here, when the content of the element X in aluminum is less than 0.3% by mass, the amount of the first and second nanoparticles formed becomes small, and an effective nanoparticle dispersed structure cannot be formed. On the other hand, if the content of element X exceeds 5% by mass, a crystallized product of an intermetallic compound having a large particle size is formed during the solidification process, and the crystallized product can be finely divided and dispersed even after strong processing. I can't. For this reason, the content of the element X is defined as 0.3% by mass or more and 5% by mass or less.

In the method for producing an aluminum alloy conductor according to the first invention, the cast structure is: 1) a primary crystal of an aluminum-based solid solution in which the element X is dissolved in aluminum and a eutectic structure of aluminum and the intermetallic compound; 2) a eutectic structure of aluminum and the intermetallic compound, 3) a crystallized product of the intermetallic compound and a eutectic structure of aluminum and the intermetallic compound, and 4) the element X is dissolved in the aluminum. The primary crystal of the aluminum-based solid solution, the eutectic structure of aluminum and the intermetallic compound, and the crystallized product of the intermetallic compound can be used.

In the method for producing an aluminum alloy conductor according to the first invention, it is preferable that a plastic deformation process having an equivalent strain of 2 or less is applied to the aluminum cast body in advance.

In the method for producing an aluminum alloy conductor according to the first invention, the element X is iron, and can be contained in aluminum in an amount of 0.6 mass% to 5 mass%.
Here, iron is preferably contained in an amount of 1.5% by mass to 2.5% by mass with respect to aluminum.
And the said aluminum cast can be cast using any one or both of an aluminum ingot and an aluminum recycling collection | recovery material.

In the method for producing an aluminum alloy conductor according to the first invention, the element X is manganese, and the aluminum may be contained in an amount of 0.6% by mass to 2.5% by mass.

In the method for producing an aluminum alloy conductor according to the first invention, the cast structure includes: 1) an aluminum-based solid solution in which the element X is dissolved in aluminum and the intermetallic compound included in the aluminum-based solid solution, or 2 The aluminum-based solid solution in which the element X is solid-solved in aluminum, the crystallized product of the intermetallic compound included in the aluminum-based solid solution, and the intermetallic compound precipitated in the aluminum-based solid solution may be used.
And the said element X is chromium, Comprising: 0.6 mass% or more and 5 mass% or less can be contained in aluminum.

A method of manufacturing an electric wire according to a second invention that meets the above-mentioned object is formed by performing a drawing process with a processing degree of 5 or more on the aluminum alloy conductor according to the first invention, and a wire diameter of 0.03 mm or more and 0.5 mm. The following conductor strands are used.

In the method for manufacturing an electric wire according to the second invention, the conductor strand is preferably heat-treated at a temperature of 350 ° C. or lower.

In the method for producing an aluminum alloy conductor according to the first invention, a eutectic reaction or a peritectic reaction occurs during solidification, so that a fine intermetallic compound is dispersed in the cast structure of the aluminum casting. For this reason, it becomes easy to refine the cast structure of an aluminum cast body by strong processing, in particular, to divide and disperse intermetallic compounds, and the cast structure passes through the aluminum fine crystal grains in which element X is supersaturated and solid-dissolved. A nanoparticle-dispersed structure having crystal grains and first and second nanoparticles made of an intermetallic compound formed by a reaction between element X and aluminum, which are present in the grains and in the grain boundaries of the aluminum fine crystal grains, respectively. Can be formed. As a result, it is possible to improve the tensile strength of the aluminum alloy conductor, and to reduce the solid solution amount of the element X in the aluminum fine crystal grains with the generation of the first and second nanoparticles, thereby reducing the aluminum alloy. The conductivity of the conductor can be improved.
In addition, since the metal structure of the aluminum alloy conductor is composed of aluminum fine crystal grains, the stretchability is improved, and even when bending is repeatedly applied to the metal structure, strain is hardly accumulated and fatigue cracks are not easily generated. Since the first and second nanoparticles are dispersed in the aluminum fine crystal grains and in the grain boundaries, respectively, even if fatigue cracks are generated, deflection and branching of the fatigue cracks are promoted during the development. , The fatigue crack growth rate decreases. As a result, the bending resistance of the aluminum alloy conductor is improved, and the aluminum alloy conductor can be used for wiring in a driving environment such as vibration or bending or in a vibration state.

In the method for producing an aluminum alloy conductor according to the first invention, the cast structure is 1) a primary crystal of an aluminum-based solid solution in which element X is dissolved in aluminum and a eutectic structure of aluminum and an intermetallic compound, 2) aluminum 3) Eutectic structure of intermetallic compound, 3) Crystallized product of intermetallic compound and eutectic structure of aluminum and intermetallic compound, and 4) Primary crystal of aluminum-based solid solution, eutectic of aluminum and intermetallic compound In the case of any one of the structure and the crystallized product of the intermetallic compound, the intermetallic compound in the cast structure can be efficiently divided and dispersed.

In the method for producing an aluminum alloy conductor according to the first invention, when a plastic deformation process having an equivalent strain of 2 or less is previously applied to the aluminum casting, the eutectic structure in the aluminum casting is roughly aligned, The eutectic structure is in a state in which the layered aluminum portions and the layered intermetallic compound portions are alternately laminated, and the eutectic structure is easily collapsed during strong processing. As a result, the separation of the intermetallic compound is further promoted, and the intermetallic compound can be dispersed more efficiently.

In the method for producing an aluminum alloy conductor according to the first invention, when the element X is iron, the amount of solid solution with respect to aluminum is small, so that the electrical conductivity of the aluminum alloy conductor can be prevented from being reduced.
And when iron contains 0.6 mass% or more and 5 mass% or less in aluminum, according to content of iron, a cast structure | tissue is used, 1) The primary crystal of the aluminum-based solid solution which iron dissolved in aluminum, and Eutectic structure, 2) eutectic structure, 3) crystallization and eutectic structure of an intermetallic compound of aluminum and iron, and 4) primary crystal, eutectic structure, and crystallization product. Can do. As a result, it is possible to form a nanoparticle dispersed structure in which the first and second nanoparticles are effectively dispersed in the aluminum fine crystal grains and in the grain boundaries, respectively.

In the method for producing an aluminum alloy conductor according to the first invention, when iron is contained in an amount of 1.5% by mass or more and 2.5% by mass or less with respect to aluminum, the cast structure of the aluminum cast body is an eutectic structure. Since the primary crystals and crystallized substances are fine, the eutectic structure, primary crystals and crystallized substances can be effectively divided by strong processing, and the refinement of the cast structure can be easily achieved.
Here, when the aluminum casting is cast using an aluminum ingot, the impurity concentration in the aluminum fine crystal grains can be reduced to increase the conductivity.
In addition, when an aluminum casting is cast using an aluminum recycled material and the iron content of the recycled aluminum material is low, or when cast using both an aluminum ingot and an aluminum recycled material, the aluminum recycled material is iron. Even when the content is large, iron can be adjusted so as to be contained in an amount of 1.5% by mass or more and 2.5% by mass or less with respect to aluminum, and the usage rate of the aluminum recycled recovered material can be improved.

In the method for producing an aluminum alloy conductor according to the first invention, when the element X is manganese and the aluminum is contained in an amount of 0.6 mass% or more and 2.5 mass% or less, depending on the manganese content, the cast structure 1) Primary crystal and eutectic structure of an aluminum-based solid solution in which manganese is dissolved in aluminum, 2) Eutectic structure, 3) Crystallized product and eutectic structure of an intermetallic compound of aluminum and manganese, and 4 ) Any one of primary crystal, eutectic structure, and crystallized product can be obtained.

In the method for producing an aluminum alloy conductor according to the first invention, the cast structure is 1) an aluminum-based solid solution in which element X is solid-solved in aluminum and an intermetallic compound included in the aluminum-based solid solution, or 2) in aluminum. When the element X is an aluminum-based solid solution in which the element X is a solid solution, a crystallized product of an intermetallic compound included in the aluminum-based solid solution, and an intermetallic compound precipitated in the aluminum-based solid solution, the separation of the intermetallic compound in the cast structure Dispersion can be performed efficiently.

In the method for producing an aluminum alloy conductor according to the first invention, when the element X is chromium and aluminum is contained in an amount of 0.6% by mass or more and 5% by mass or less, depending on the chromium content, 1) an aluminum-based solid solution in which chromium is dissolved in aluminum and an intermetallic compound included in the aluminum-based solid solution, or 2) a crystallized product of an aluminum-based solid solution, an intermetallic compound included in the aluminum-based solid solution, and an aluminum group It can be an intermetallic compound precipitated in the solid solution. As a result, it is possible to form a nanoparticle dispersed structure in which the first and second nanoparticles are effectively dispersed in the aluminum fine crystal grains and in the grain boundaries, respectively.

In the method for producing an aluminum alloy conductor according to the first invention, the aluminum fine crystal grains have a particle size of 800 nm or less, the first and second nanoparticles have a particle size of 500 nm or less, and a tensile force during a tensile test at room temperature. When the strength is 220 MPa or more, the number of breaks in a repeated bending test at room temperature is 3 million times or more, and the electrical conductivity at room temperature is 50% IACS or more, in fields that require high reliability such as industrial robots and aircraft It can be used as a conductive material for the cable used.

In the method for producing an aluminum alloy conductor according to the first invention, when the aluminum cast body is heat-treated at a temperature of 300 ° C. or less before or during strong processing, a cast structure of the aluminum cast body is formed. The grain growth of the crystal grains can be prevented, the strain existing in the crystal grains can be removed, the extensibility of the aluminum casting can be improved, and the strong processing can be efficiently performed.

In the method for producing an aluminum alloy conductor according to the first invention, when the aluminum alloy conductor is heat-treated at a temperature of 300 ° C. or lower, removal of processing strain present in the aluminum alloy conductor formed through strong processing is performed. This can be performed while preventing the grain growth of the aluminum fine crystal grains and the first and second nanoparticles forming the aluminum alloy conductor. Thereby, the secondary processing of the aluminum alloy conductor can be easily performed.

In the method for manufacturing the electric wire according to the second invention, the cast structure of the aluminum alloy conductor according to the first invention is refined and configured with equiaxed crystal grains. The conductor wire formed by performing the drawing process at a degree of 5 or more is formed with a structure in which fine crystal grains are oriented with the longitudinal direction oriented in the drawing process direction. Thereby, it is possible to remarkably improve the fatigue resistance against stress strain applied in a direction orthogonal to the wire drawing direction (drawing direction), that is, stress strain when bending deformation is applied to the conductor wire. And by making the wire diameter of the conductor wire 0.03 mm or more and 0.5 mm or less, the absolute value of stress strain generated when bending is repeatedly applied to the conductor wire can be reduced. Flexibility can be improved. As a result, early disconnection at the time of using the electric wire can be prevented, the reliability of various devices using the electric wire can be improved, and the maintenance burden on the various devices can be reduced.

In the method for manufacturing an electric wire according to the second invention, when the conductor strand is heat-treated at a temperature of 350 ° C. or lower, the grain growth of the crystal grains constituting the conductor strand is prevented and exists in the crystal grains. The strain to be removed can be removed, and the elongation of the conductor wire can be improved. For this reason, even if bending is repeatedly applied to the metal structure, strain is hardly accumulated in the metal structure. Thereby, the bending resistance of an electric wire can further be improved.

It is a schematic diagram of the HPT method.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
The aluminum alloy conductor manufactured by the manufacturing method according to the first embodiment of the present invention generates an intermetallic compound with aluminum, and the eutectic reaction is performed in a region where the amount of addition to aluminum is 5% by mass or less. In an aluminum cast body that has a reaction composition to be produced and further contains 0.6% by mass or more and 5% by mass or less of iron which is an example of the element X whose solid solution limit with respect to aluminum is less than the reaction composition, the equivalent strain is 100 or more. It is manufactured by applying strong processing. In addition, since iron dissolves only 0.052 mass% in aluminum, even if iron is added to aluminum, it is possible to prevent the electrical conductivity of aluminum from being greatly impaired.

For example, an HPT (High-Pressure Torsion) method is employed as a method of subjecting the aluminum casting to strong processing with an equivalent strain of 100 or more. In the HPT method, as shown in FIG. 1, a disk-shaped workpiece 10 is provided with concave depressions 11 and 11a formed along the shape of the workpiece 10 at the center, respectively, and a lower anvil. The lower anvil 13 is rotated with respect to the upper anvil 12 while being sandwiched between 12 and 13 and a large pressure is applied to the workpiece 10, thereby introducing shear strain into the workpiece 10. Here, when the thickness of the workpiece 10 is t and the rotation angle of the lower anvil 13 is θ, the equivalent strain ε _{θ at} the position of the radius r from the center of the workpiece 10 is θr / (3 ^1/2 t ) Therefore, when the shape of the workpiece 10 is fixed, the equivalent strain applied to the workpiece 10 can be adjusted by managing the rotation angle of the lower anvil 13 during strong machining, that is, the number of rotations. Note that the shape of the workpiece may be annular. In an annular workpiece, the difference in strain introduced between the inner periphery and the outer periphery of the workpiece is small, and the structure of the workpiece can be refined efficiently.

The cast structure of the cast aluminum body, that is, the cast structure of the workpiece 10 is 1) a primary crystal of an aluminum-based solid solution in which iron is dissolved in aluminum and a eutectic structure of aluminum and an Al—Fe intermetallic compound, 2) Eutectic structure of aluminum and Al—Fe intermetallic compound, 3) Crystallized product of Al—Fe intermetallic compound and eutectic structure of aluminum and Al—Fe intermetallic compound, and 4) Aluminum. One of the primary crystal of the base solid solution, the eutectic structure of aluminum and the Al—Fe intermetallic compound, and the crystallization product of the Al—Fe intermetallic compound. For this reason, when the workpiece 10 is subjected to strong processing, the primary crystal, eutectic structure, and crystallized material existing in the cast structure of the workpiece 10 are gradually refined by being repeatedly divided by strong processing, For example, it is composed of an equiaxed aluminum fine crystal grain having a particle size of 800 nm or less and an Al—Fe-based intermetallic compound existing in the aluminum fine crystal grain. By forming a nanoparticle-dispersed structure consisting of particles and second nanoparticle having a particle diameter of 500 nm or less, including aluminum and Al—Fe-based intermetallic compound existing at the grain boundary of aluminum fine crystal grains, aluminum An alloy conductor is formed. The Al—Fe intermetallic compound refers to either one or both of Al ₃ Fe and Al ₆ Fe.

Since the metal structure of the aluminum alloy conductor is composed of aluminum fine crystal grains, the extensibility is improved, and even if bending is repeatedly applied to the metal structure, strain is hardly accumulated and fatigue cracks are not easily generated. Even if a fatigue crack is generated, if the fatigue crack propagates through the grain boundary of the aluminum fine crystal grain, the fatigue crack is deflected and branched along the grain boundary. Therefore, when a fatigue crack collides with the second nanoparticle, deflection and branching of the fatigue crack occur. On the other hand, when the fatigue crack propagates in the aluminum fine crystal grains, the first nanoparticles are dispersed in the aluminum fine crystal grains, so that the fatigue crack collides with the first nanoparticles. Fatigue crack deflection and bifurcation occur. Thereby, the growth rate of fatigue cracks is reduced. As a result, the bending resistance of the aluminum alloy conductor is improved, and the aluminum alloy conductor can be used for wiring in a driving environment such as vibration or bending or in a vibration state.

The cast aluminum body has a purity of 99.9% by mass (the balance is inevitable impurities) and a predetermined amount of 99% by mass of iron ingot (the balance is inevitable impurities). It is prepared by preparing a blend having a rate of 0.6% by mass or more and 5% by mass or less, dissolving the blend at 780 to 830 ° C., and then cooling. Here, the reaction composition in which the eutectic reaction occurs between aluminum and iron is such that the amount of iron added to aluminum is 2% by mass, so the iron content to aluminum is 0.6% by mass or more and less than 2% by mass. When the melt of the hypoeutectic alloy composition is cooled, when the temperature of the melt passes the liquidus temperature, an aluminum-based solid solution primary crystal in which iron is dissolved in the aluminum is formed in the melt, and further, When the cooling proceeds and the temperature reaches the eutectic temperature (652 ° C.), the dissolved material is in a mixed state of a liquid phase having a primary crystal and a eutectic composition. The liquid phase having the eutectic composition is solidified at a temperature just below the eutectic temperature to form a eutectic structure (a complex structure of aluminum and an Al—Fe intermetallic compound). As a result, the cast structure of the aluminum cast body is in a state in which a eutectic structure exists between the primary crystal grains.

On the other hand, when cooling a melt having a eutectic alloy composition in which the iron content relative to aluminum is 2% by mass, the melt solidifies at a temperature just below the eutectic temperature to form a eutectic structure. . As a result, the cast structure of the aluminum casting is composed of a eutectic structure.
In addition, when cooling a melt having a hypereutectic alloy composition in which the content of iron with respect to aluminum exceeds 2 mass% and is 5 mass% or less, when the temperature of the melt passes the liquidus temperature, Al is contained in the melt. _When a crystallized product of ₃ Fe is generated and the cooling further proceeds and the temperature reaches the eutectic temperature, the dissolved material becomes a mixed state of the crystallized product and the liquid phase of the eutectic composition. The liquid phase having the eutectic composition is solidified at a temperature just below the eutectic temperature to form a eutectic structure. As a result, the cast structure of the aluminum cast body is in a state in which crystallized substances are dispersed in the eutectic structure.

When the melt is cooled, if a temperature difference (cooling rate distribution) occurs in the melt, primary crystals are generated in a region where solidification has progressed rapidly. For this reason, in the case of a melt having a eutectic alloy composition, if the temperature of the melt as a whole decreases to just below the eutectic temperature, the liquid phase of the eutectic composition solidifies to form a eutectic structure. The cast structure is in a state where primary crystals are scattered in the eutectic structure. In the case of a melt having a hypereutectic alloy composition, when the temperature of the melt as a whole passes the liquidus temperature, a crystallized product of an Al-Fe intermetallic compound is further generated in the melt, and the eutectic is obtained. When the temperature is reached, the melt becomes a mixed state of the primary phase, the crystallized product, and the liquid phase of the eutectic composition, and the liquid phase of the eutectic composition is solidified at a temperature just below the eutectic temperature. In order to form the structure, the cast structure of the aluminum cast body is in a state where the primary crystal, the eutectic structure, and the crystallized substance coexist.

When producing an aluminum casting, an aluminum recycled material can be used instead of using an aluminum ingot. At present, the ratio of iron-based materials is very high among metal-based materials used in various applications. For this reason, the content of iron contained as an impurity in the aluminum recycled material has also increased. Therefore, by using the aluminum recycling material, it is possible to effectively use iron contained as impurities in addition to aluminum. If the iron content contained in the recycled aluminum material is less than the required iron content in the aluminum casting, the iron content can be increased by adding a predetermined amount of iron to the recycled aluminum material. Increase to the required amount. On the other hand, if the iron content contained in the recycled aluminum material is greater than the iron content required in the aluminum casting, the iron content is reduced to the required amount by combining with a predetermined amount of aluminum ingot. To reduce.

When the workpiece 10 produced from the aluminum casting is repeatedly subjected to strong processing by the HPT method, dislocations accumulate in the aluminum crystal grains (primary crystal, aluminum portion in the eutectic structure) in the cast structure of the workpiece 10. Then, when the sub-crystal grain boundary is formed and the total sum of the equivalent strains introduced into the workpiece 10 becomes 100 or more, the crystal grains are refined through the sub-crystal grain boundary. On the other hand, in the case of Al-Fe intermetallic compounds (Al-Fe intermetallic compound portion in the eutectic structure, crystallized product), fine fragmentation and dispersion (partial) of the Al-Fe intermetallic compound by repeated strong processing. Occurs as a solid solution in aluminum crystal grains as iron.

Here, a plastic deformation process having an equivalent strain of 2 or less may be applied to the workpiece 10 before performing the strong process. When plastic deformation is performed on the workpiece 10 with an equivalent strain of 2 or less, the eutectic structure in the workpiece 10 is roughly aligned, that is, the eutectic structure is between the layered aluminum portion and the layered Al—Fe-based metal. The compound portions can be alternately stacked. Thereby, in the eutectic structure, the Al—Fe-based intermetallic compound part is deformed due to the deformation of the aluminum part, so that the eutectic structure is easily collapsed. As a result, the division of the Al—Fe-based intermetallic compound portion in the cast structure is promoted, and the Al—Fe-based intermetallic compound can be more efficiently dispersed.
In addition, as a method of applying plastic deformation processing with an equivalent strain of 2 or less to the workpiece 10, for example, an ECAP (Equal-Channel Angular Pressing) method or a roll rolling method with an equivalent strain of 1 or less can be employed. . The equivalent strain applied to the workpiece 10 can be adjusted by the number of repetitions of plastic deformation.

As a result, at the end of the strong processing, for example, it is composed of an aluminum fine crystal grain having a particle size of 800 nm or less and an Al—Fe-based intermetallic compound existing in the aluminum fine crystal grain. A nanoparticle-dispersed structure comprising the following first nanoparticles and an Al—Fe-based intermetallic compound existing at the grain boundary of the aluminum fine crystal grains, for example, a second nanoparticle having a particle diameter of 500 nm or less. As a result, an aluminum alloy conductor is formed.

Here, when the iron content in the aluminum casting exceeds the solid solution limit, the iron content in the aluminum fine crystal grains formed during the strong processing gradually increases by repeating strong processing. At the end of the strong processing, the iron content in the aluminum fine crystal grains is in a supersaturated state. For this reason, the aluminum alloy conductor obtained by strong processing is heat-treated at a temperature of 300 ° C. or lower in an inert atmosphere (for example, in an argon gas atmosphere), thereby preventing grain growth of aluminum fine crystal grains, The supersaturated iron in the aluminum fine crystal grains can be precipitated as an Al-Fe intermetallic compound to form second nanoparticles, and the amount of iron solid solution in the aluminum fine crystal grains can be reduced. . As a result, the electrical conductivity at room temperature of the aluminum alloy conductor can be 50% IACS or more. If the heat treatment temperature exceeds 300 ° C., the growth of aluminum fine crystal grains becomes remarkable and the formed microstructure is broken, which is not preferable. On the other hand, as the heat treatment temperature is lowered, the treatment time required for the heat treatment is drastically increased and the productivity is lowered. For this reason, the minimum of practical heat processing temperature is about 150 degreeC, for example, and processing time will be 0.2 to 40 hours.

In addition, when the iron content in the aluminum cast body exceeds the solid solution limit, the workpiece 10 can be heat-treated at a temperature of 300 ° C. or less during strong processing. As a result, while preventing the grain growth of the aluminum fine crystal grains formed during strong processing, even if the iron content dissolved in the aluminum fine crystal grains gradually increases by repeating the strong processing, the aluminum The Al—Fe-based intermetallic compound can be precipitated in the fine crystal grains to form second nanoparticles, and the amount of iron solid solution in the aluminum fine crystal grains can be reduced. As a result, the electrical conductivity at room temperature of the aluminum alloy conductor can be 50% IACS or more. Since the workpiece 10 generates heat during processing (generation of frictional heat) during strong processing, it is necessary to control the heating so that the temperature of the workpiece 10 is 300 ° C. or less. When the temperature of the work piece 10 exceeds 300 ° C. during the strong working, the formation of the aluminum fine crystal grains and the grain growth of the aluminum fine crystal grains proceed simultaneously to efficiently form a fine structure in the work piece 10. I can't. On the other hand, when the temperature of the workpiece 10 is too low during strong machining, for example, when the temperature of the workpiece 10 is less than 150 ° C., the Al—Fe-based metal forming nanoparticles in the aluminum fine grain Since the precipitation rate of the compound is reduced and the formation of the second nanoparticles cannot be efficiently performed during the strong processing, it is necessary to heat the workpiece 10 so that the temperature of the workpiece 10 is 150 to 300 ° C. .

Further, the workpiece 10 may be subjected to a strong heat treatment in advance at a temperature of 300 ° C. or less. By performing the heat treatment, the cooling strain introduced into the workpiece 10 can be removed while preventing the growth of the aluminum crystal grains constituting the cast structure of the workpiece 10. Thereby, the strong processing of an aluminum casting can be performed efficiently. Note that when the heat treatment temperature exceeds 300 ° C., grain growth occurs in the crystal grains constituting the workpiece 10 and precipitates of the Al—Fe-based intermetallic compound, and the refinement of the structure is effectively performed by the strong processing. Cannot be implemented. Here, when the heat treatment temperature is lowered, the treatment time required for the heat treatment is drastically increased and the productivity is lowered. Therefore, the practical lower limit of the heat treatment temperature is, for example, about 150 ° C. 2 to 40 hours.

The proportion of the first and second nanoparticles constituting the nanoparticle dispersed structure of the aluminum alloy conductor depends on the amount of Al-Fe intermetallic compound crystallized material in the aluminum casting, The amount of product present is determined by the iron content in the melt. Here, by containing at least 0.3% by mass of iron with respect to aluminum, the first and second nanoparticles exist in the grains of the aluminum fine crystal grains and in the grain boundaries, respectively, and the fatigue crack is deflected. And branching can occur. And by containing at least 0.6 mass% of iron with respect to aluminum, the deflection | deviation of a fatigue crack and generation | occurrence | production of a branch can be made remarkable.

On the other hand, the particle size of the first and second nanoparticles depends on the fine cutting efficiency of the Al—Fe-based intermetallic compound by strong processing, and the dispersion state of the first and second nanoparticles is formed by strong processing. It depends on the dispersion efficiency of the finely divided material. For this purpose, it is preferable that the particle size of the Al—Fe-based intermetallic compound present in the aluminum casting is small. Here, the grain size of the Al—Fe intermetallic compound in the cast structure is generally larger in the crystallized product than the Al—Fe intermetallic compound part in the eutectic structure. In order to reduce the particle size of the crystallized product, it is necessary to reduce the difference between the crystallized product start temperature and the eutectic temperature. The crystallized product start temperature is the iron content in the melt. Determined by.

Therefore, the aluminum castings produced by cooling the hypereutectic alloy composition having various iron contents were subjected to strong processing with an equivalent strain of 100 or more, respectively, and the fractionation efficiency and dispersion efficiency of the crystallized product When the iron content with respect to aluminum is 5% by mass or less, the crystallized product is finely divided into particles having a particle size of 500 nm or less by strong processing having an equivalent strain of 100 or more. It was confirmed that the first and second nanoparticles can be dispersed in the inner and grain boundaries, respectively. For this reason, the range of iron content with respect to aluminum was defined as 0.3 mass% or more, preferably 0.6 mass% or more and 5 mass% or less.
In addition, when the iron content with respect to aluminum exceeds 5 mass%, even if the crystallized material is refined, there are particles having a particle size exceeding 500 nm. Since these particles act as defects, they cause, for example, a decrease in tensile strength, a decrease in bending resistance, and a disconnection during wire drawing.

Here, in order to achieve fine cutting and dispersion of Al-Fe-based intermetallic compounds with high efficiency and high precision by strong processing, in the cast structure of an aluminum cast body, Al-Fe-based intermetallic compounds It is preferable that the particle size of the material is small and is uniformly dispersed in the cast structure. Such a cast structure is obtained when the melt has a eutectic alloy composition. Accordingly, aluminum alloys produced by cooling various compositions having iron contents from the hypoeutectic alloy composition side to the hypereutectic alloy composition side centered on the eutectic alloy composition have respective strains. When micro-cutting efficiency and dispersion efficiency of the crystallized product were observed under a microscope by performing strong processing of 100 or more, Al was as strong as the case of a cast structure having a eutectic alloy composition by strong processing of equivalent strain of 100 or more. The Fe-based intermetallic compound is finely divided to a particle size of 500 nm or less, and can be dispersed as first and second nanoparticles in the aluminum fine crystal grains and in the grain boundaries, respectively. It was confirmed that the content of was in the range of 1.5 mass% to 2.5 mass%. For this reason, the optimal range of iron content with respect to aluminum was prescribed | regulated as 1.5 mass% or more and 2.5 mass% or less.

Then, the electric wire manufactured with the manufacturing method which concerns on the 2nd Embodiment of this invention is demonstrated.
The electric wire manufactured by the manufacturing method according to the second embodiment is formed by drawing a aluminum alloy conductor manufactured by the manufacturing method according to the first embodiment with a processing degree of 5 or more. Is formed using a conductor wire having a thickness of 0.03 mm to 0.5 mm.
The conductor wire is made of a plate-shaped aluminum alloy conductor produced by subjecting an aluminum casting containing 0.3% by mass or more and 5% by mass or less of iron to a strong processing with an equivalent strain of 100 or more. The rod is manufactured by cutting, and is formed by performing swaging and die drawing (drawing).

Here, since the cast structure of the aluminum alloy conductor manufactured by the manufacturing method according to the first embodiment is made up of refined and equiaxed crystal grains, die drawing (drawing) is performed. The conductor wire formed in (1) is formed of an oriented structure having fine crystal grains whose longitudinal direction is along the drawing direction. Thereby, it is possible to remarkably improve the fatigue resistance against stress strain applied in a direction orthogonal to the wire drawing direction (drawing direction), that is, stress strain when bending deformation is applied to the conductor wire. And the absolute value of the stress distortion generate | occur | produced when bending is repeatedly applied to a conductor strand can be made small because the wire diameter of a conductor strand shall be 0.03 mm or more and 0.5 mm or less. As a result, the bending resistance of the electric wire formed using this conductor wire is improved, and even if this electric wire is used for wiring in a driving environment or vibration state such as vibration or bending, early disconnection can be prevented. The reliability of various devices (industrial robots, mobile machines such as automobiles and airplanes) using this electric wire can be improved, and the maintenance burden on the various devices can be reduced.

The produced conductor wire is heat-treated at a temperature of 350 ° C. or lower, for example, in an argon gas atmosphere, for example, for 0.2 to 40 hours. By performing heat treatment, the strain existing in the crystal grains (strain introduced during swaging and die wire drawing) is removed while preventing the growth of the grains constituting the conductor wire. It is possible to improve the extensibility of the conductor wire. For this reason, even if bending is repeatedly applied to the electric wire, strain is not easily accumulated in the metal structure constituting the electric wire (conductor wire).
In addition, it is preferable to select the timing and degree (temperature and time) of the heat treatment according to the degree of processing and workability (the production rate of the conductor wire) of the workpiece. For example, if heat generation of the workpiece can be expected during die drawing, heat treatment is not necessary. On the other hand, when the wire diameter of the conductor wire is small, for example, 0.03 to 0.1 mm, heat treatment can be performed before the die drawing and during the die drawing.

The aluminum alloy conductor manufactured by the manufacturing method according to the third embodiment of the present invention generates an intermetallic compound with aluminum, and the peritectic reaction is performed in a region where the addition amount with respect to aluminum is 5% by mass or less. An aluminum cast body having a generated reaction composition and further containing 0.6 mass% or more and 5 mass% or less of chromium, which is an example of the element X whose solid solution limit with respect to aluminum is less than the reaction composition, has an equivalent strain of 100 or more. It is manufactured by applying strong processing. In addition, since chromium dissolves only 0.72% by mass in aluminum, even if chromium is added to aluminum, it is possible to prevent the electrical conductivity of aluminum from being greatly impaired.

Here, the cast structure of the aluminum cast body, that is, the cast structure of the work piece is 1) an aluminum-based solid solution in which chromium is solid-solved in aluminum and an Al—Cr-based intermetallic compound included in the aluminum-based solid solution, or 2) An aluminum-based solid solution in which chromium is dissolved in aluminum, an Al-Cr-based intermetallic compound crystallized in the aluminum-based solid solution, and an Al-Cr-based intermetallic compound precipitated in the aluminum-based solid solution. . For this reason, when the workpiece is subjected to strong machining, the aluminum-based solid solution present in the cast structure of the workpiece, the Al-Cr-based intermetallic compound included in the aluminum-based solid solution, the Al-Cr-based intermetallic compound For the Al-Cr intermetallic compound precipitated in the crystallized product and the aluminum-based solid solution, the fragmentation by strong processing is repeated and gradually refined and dispersed. For example, the particle size is 800 nm or less and is equiaxed. Aluminum fine crystal grains and an Al-Cr intermetallic compound existing in the aluminum fine crystal grains, for example, the first nanoparticles having a particle size of 500 nm or less, and the grain boundaries of the aluminum fine crystal grains For example, an aluminum alloy conductor formed of a nanoparticle-dispersed structure having a second nanoparticle having a particle diameter of 500 nm or less is formed. Made. The Al—Cr intermetallic compound refers to, for example, Al ₇ Cr.

Since the metal structure of the aluminum alloy conductor is composed of aluminum fine crystal grains, the extensibility is improved, and even if bending is repeatedly applied to the metal structure, strain is hardly accumulated and fatigue cracks are not easily generated. Even if a fatigue crack is generated, if the fatigue crack propagates through the grain boundary of the aluminum fine crystal grain, the fatigue crack is deflected and branched along the grain boundary. Therefore, when a fatigue crack collides with the second nanoparticle, deflection and branching of the fatigue crack occur. On the other hand, when the fatigue crack propagates in the aluminum fine crystal grains, the first nanoparticles are dispersed in the aluminum fine crystal grains, so that the fatigue crack collides with the first nanoparticles. Fatigue crack deflection and bifurcation occur. Thereby, the growth rate of fatigue cracks is reduced. As a result, the bending resistance of the aluminum alloy conductor is improved, and the aluminum alloy conductor can be used for wiring in a driving environment such as vibration or bending or in a vibration state.

The cast aluminum body has a purity of 99.9% by mass, an addition of a predetermined amount of 99% by mass of chromium ingot (the balance is an unavoidable impurity), and the chromium content relative to aluminum is 0.6% by mass. A blend of 5% by mass or less is prepared, and the blend is dissolved, for example, at 780 to 850 ° C., and then cooled. Here, in the region where the chromium content with respect to aluminum is 5% by mass or less, the reaction composition in which the peritectic reaction occurs between aluminum and chromium is 0.41% by mass and 1% by mass with the addition of chromium to aluminum. There are two. Therefore, when cooling a melt having a peritectic alloy composition in which the chromium content with respect to aluminum is 0.6% by mass or more and less than 1% by mass, when the temperature of the melt passes the liquidus temperature, a metal is contained in the melt. When the intermetallic compound Al ₇ Cr is generated and further cooling proceeds and the temperature reaches the peritectic temperature 661 ° C., the dissolved material is in a mixed state of the intermetallic compound Al ₇ Cr and the liquid phase of the peritectic composition. The liquid phase having a peritectic composition is solidified at a temperature just below the peritectic temperature to form a peritectic structure (aluminum-based solid solution and Al ₇ Cr included in the aluminum-based solid solution). When the temperature further decreases, the solid solution limit of chromium in the aluminum-based solid solution gradually decreases, so that Al ₇ Cr is precipitated in the aluminum-based solid solution. As a result, the cast structure of the aluminum cast is an aluminum-based solid solution, Al 7 that are subsumed aluminum base solid solution _Cr, a state where Al 7 precipitated in an aluminum base solid solution _Cr is present.

On the other hand, when cooling a melt having a peritectic alloy composition having a chromium content of 1% by mass or more and 5% by mass or less with respect to aluminum, when the temperature of the melt passes the liquidus temperature, a crystallized product is formed in the melt (Intermetallic compound Al ₁₁ Cr ₂ ) is generated, and when the cooling further proceeds and the temperature reaches the peritectic temperature of 725 ° C., the intermetallic compound Al ₇ Cr is newly generated in the melt, and the temperature The production amount of the intermetallic compound Al ₇ Cr increases with the decrease. Next, when the temperature reaches the peritectic temperature 661 ° C. on the low temperature side, the dissolved material is in a mixed state of the intermetallic compound Al ₇ Cr and the liquid phase of the peritectic composition. The liquid phase having a peritectic composition is solidified at a temperature just below the peritectic temperature to form a peritectic structure (aluminum-based solid solution and Al ₇ Cr included in the aluminum-based solid solution). When the temperature further decreases, the solid solution limit of chromium in the aluminum-based solid solution gradually decreases, so that Al ₇ Cr is precipitated in the aluminum-based solid solution. As a result, the cast structure of the aluminum cast is an aluminum-based solid solution, a state where Al 7 that are subsumed aluminum base solid solution _Cr, and Al 7 _Cr deposited on an aluminum base solid solution exists.

Here, when the chromium content in the aluminum casting exceeds the solid solution limit, the chromium content in the aluminum fine crystal grains formed during the strong processing gradually increases by repeating strong processing. At the end of strong processing, the chromium content in the aluminum fine crystal grains is in a supersaturated state. For this reason, the aluminum alloy conductor obtained by strong processing is heat-treated at a temperature of 300 ° C. or lower in an inert atmosphere (for example, in an argon gas atmosphere), thereby preventing grain growth of aluminum fine crystal grains, The supersaturated chromium in the aluminum fine crystal grains can be precipitated as the intermetallic compound Al ₇ Cr to form second nanoparticles, and the amount of chromium solid solution in the aluminum fine crystal grains can be reduced. As a result, the electrical conductivity at room temperature of the aluminum alloy conductor can be 50% IACS or more. If the heat treatment temperature exceeds 300 ° C., the growth of aluminum fine crystal grains becomes remarkable and the formed microstructure is broken, which is not preferable. On the other hand, as the heat treatment temperature is lowered, the treatment time required for the heat treatment is drastically increased and the productivity is lowered. For this reason, the minimum of practical heat processing temperature is about 150 degreeC, for example, and processing time will be 0.2 to 40 hours.

In addition, when the chromium content in the aluminum casting exceeds the solid solution limit, it is possible to heat-treat the workpiece at a temperature of 300 ° C. or less during strong processing. As a result, while preventing the grain growth of the aluminum fine crystal grains formed during strong processing, even if the chromium content dissolved in the aluminum fine crystal grains gradually increases by repeating strong processing, the aluminum The second nanoparticle can be formed by precipitating the intermetallic compound Al ₇ Cr in the fine grain, and the amount of chromium solid solution in the aluminum fine grain can be reduced. As a result, the electrical conductivity at room temperature of the aluminum alloy conductor can be 50% IACS or more. In addition, since the workpiece generates heat during processing (generation of frictional heat) during strong processing, it is necessary to control the heating so that the temperature of the workpiece is 300 ° C. or less. When the temperature of the workpiece exceeds 300 ° C. during strong processing, formation of aluminum fine crystal grains and grain growth of aluminum fine crystal grains proceed simultaneously, and a fine structure can be efficiently formed in the workpiece. Can not. On the other hand, when the temperature of the workpiece is too low during strong processing, for example, when the temperature of the workpiece is less than 150 ° C., the intermetallic compound Al ₇ that forms Al- nanoparticles in the aluminum fine crystal grains. Since the precipitation rate of Cr becomes small and the formation of the second nanoparticles cannot be performed efficiently during the strong processing, it is necessary to heat the workpiece to a temperature of 150 to 300 ° C.

Further, the work piece may be subjected to heat treatment in advance at a temperature of 300 ° C. or less and then subjected to strong processing. By performing the heat treatment, the cooling strain introduced into the workpiece 10 can be removed while preventing the growth of the aluminum crystal grains constituting the cast structure of the workpiece 10. Thereby, the strong processing of an aluminum casting can be performed efficiently. When the heat treatment temperature exceeds 300 ° C., grain growth occurs in the crystal grains constituting the workpiece 10 and precipitates of the intermetallic compound Al ₇ Cr, and the refinement of the structure is effectively carried out by strong processing. Can not. Here, when the heat treatment temperature is lowered, the treatment time required for the heat treatment is drastically increased and the productivity is lowered. Therefore, the practical lower limit of the heat treatment temperature is, for example, about 150 ° C. 2 to 40 hours.

The ratio of the first and second nanoparticles constituting the nanoparticle dispersed structure of the aluminum alloy conductor depends on the amount of Al—Cr intermetallic compound in the aluminum casting, and between the Al—Cr intermetallics. The amount of compound present is determined by the chromium content in the lysate. Here, by containing at least 0.6% by mass of chromium with respect to aluminum, the first and second nanoparticles are present in the grains of the aluminum fine crystal grains and in the grain boundaries, respectively, and the fatigue crack is deflected. And branching can occur.

On the other hand, the particle size of the first and second nanoparticles depends on the fine cutting efficiency of the Al—Cr-based intermetallic compound by strong processing, and the dispersion state of the first and second nanoparticles is formed by strong processing. It depends on the dispersion efficiency of the finely divided material. For this purpose, it is preferable that the particle diameter of the Al—Cr intermetallic compound present in the aluminum casting is small. And in order to make the particle size of an Al-Cr type intermetallic compound small, the production | generation start temperature of an Al-Cr type | system | group intermetallic compound is determined by chromium content in a melt.

Therefore, fine casting of Al-Cr-based intermetallic compounds was performed on aluminum castings produced by cooling melts of overperitectic alloy compositions having various chromium contents, each of which was strongly processed with an equivalent strain of 100 or more. The efficiency and dispersion efficiency were observed under a microscope. When the chromium content with respect to aluminum was 5% by mass or less, the crystallized product was finely divided into particle sizes of 500 nm or less by strong processing with an equivalent strain of 100 or more, and the aluminum fineness was reduced. It was confirmed that the first and second nanoparticles could be dispersed in the crystal grains and in the grain boundaries. For this reason, the range of the chromium content with respect to aluminum is defined as 0.6 mass% or more and 5 mass% or less.
In addition, when the chromium content with respect to aluminum exceeds 5 mass%, even if the crystallized material is refined, there are those having a particle size exceeding 500 nm. Since these particles act as defects, they cause, for example, a decrease in tensile strength, a decrease in bending resistance, and a disconnection during wire drawing.

Here, in order to achieve fine cutting and dispersion of Al-Cr-based intermetallic compounds with high efficiency and high precision by strong processing, in the cast structure of an aluminum cast body, Al-Cr-based intermetallic compounds It is preferable that the particle size of the material is small and is uniformly dispersed in the cast structure. Such a cast structure is obtained when the melt has a peritectic alloy composition. Accordingly, aluminum alloys produced by cooling various compositions having chromium content from the sub-peritectic alloy composition side to the super-peritectic alloy composition side centered on the peritectic alloy composition have respective strains. When microfabrication efficiency and dispersion efficiency of the crystallized material were observed under a microscope after performing strong processing of 100 or more, Al equivalent to the cast structure of peritectic alloy composition was obtained by strong processing of equivalent strain of 100 or more. The chromium-based intermetallic compound can be finely divided into a particle size of 500 nm or less, and dispersed as first and second nanoparticles in the aluminum fine crystal grains and in the grain boundaries, respectively. It was confirmed that the content of was in the range of 0.6 mass% or more and 5 mass% or less.

Then, the electric wire manufactured with the manufacturing method which concerns on the 4th Embodiment of this invention is demonstrated.
The electric wire manufactured by the manufacturing method according to the fourth embodiment is formed by drawing a aluminum alloy conductor manufactured by the manufacturing method according to the third embodiment with a processing degree of 5 or more. Is formed using a conductor wire having a thickness of 0.03 mm to 0.5 mm.
The conductor wire is a plate-shaped aluminum alloy conductor produced by subjecting an aluminum casting containing 0.6 mass% or more and 5 mass% or less of chromium to a strong strain having an equivalent strain of 100 or more, for example, a diameter of 1 mm. The rod is manufactured by cutting, and is formed by performing swaging and die drawing (drawing).

Here, since the cast structure of the aluminum alloy conductor manufactured by the manufacturing method according to the third embodiment is made up of refined and equiaxed crystal grains, die drawing (drawing) is performed. The conductor wire formed in (1) is formed of an oriented structure having fine crystal grains whose longitudinal direction is along the drawing direction. Thereby, it is possible to remarkably improve the fatigue resistance against stress strain applied in a direction orthogonal to the wire drawing direction (drawing direction), that is, stress strain when bending deformation is applied to the conductor wire. And the absolute value of the stress distortion generate | occur | produced when bending is repeatedly applied to a conductor strand can be made small because the wire diameter of a conductor strand shall be 0.03 mm or more and 0.5 mm or less. As a result, the bending resistance of the electric wire formed using this conductor wire is improved, and even if this electric wire is used for wiring in a driving environment or vibration state such as vibration or bending, early disconnection can be prevented. The reliability of various devices (industrial robots, mobile machines such as automobiles and airplanes) using this electric wire can be improved, and the maintenance burden on the various devices can be reduced.

The produced conductor wire is heat-treated at a temperature of 350 ° C. or lower, for example, in an argon gas atmosphere, for example, for 0.2 to 40 hours. By performing heat treatment, the strain existing in the crystal grains (strain introduced during swaging and die wire drawing) is removed while preventing the growth of the grains constituting the conductor wire. It is possible to improve the extensibility of the conductor wire. For this reason, even if bending is repeatedly applied to the electric wire, strain is not easily accumulated in the metal structure constituting the electric wire (conductor wire).
In addition, it is preferable to select the timing and degree (temperature and time) of the heat treatment according to the degree of processing and workability (the production rate of the conductor wire) of the workpiece. For example, if heat generation of the workpiece can be expected during die drawing, heat treatment is not necessary. On the other hand, when the wire diameter of the conductor wire is small, for example, 0.03 to 0.1 mm, heat treatment can be performed before the die drawing and during the die drawing.

The aluminum alloy conductor produced by the production method according to the fifth embodiment of the present invention produces an intermetallic compound with aluminum, and the eutectic reaction occurs in a region where the addition amount to aluminum is 5 mass% or less. In an aluminum cast body that has a reaction composition to be produced, and further contains 0.6 mass% to 2.5 mass% of manganese, which is an example of the element X whose solid solution limit with respect to aluminum is less than the reaction composition, an equivalent strain is present. Manufactured by applying 100 or more hard workings. Since manganese is only 1.25% by mass in aluminum, even if manganese is added to aluminum, it can be prevented that the electrical conductivity of aluminum is greatly impaired.

The cast structure of the aluminum cast body, that is, the cast structure of the workpiece is as follows: 1) Primary crystal of an aluminum-based solid solution in which manganese is dissolved in aluminum and a eutectic structure of aluminum and an Al—Mn intermetallic compound; 3) eutectic structure of aluminum and Al-Mn intermetallic compound, 3) crystallized product of Al-Mn intermetallic compound and eutectic structure of aluminum and Al-Mn intermetallic compound, and 4) aluminum group One of a primary crystal of a solid solution, a eutectic structure of aluminum and an Al—Mn intermetallic compound, and a crystallized product of an Al—Mn intermetallic compound. For this reason, when the work is subjected to strong processing, the primary crystal, eutectic structure, and crystallized material present in the cast structure of the work are gradually refined by repeated cutting, for example, An aluminum fine crystal grain having an equiaxed crystal grain size of 800 nm or less and an Al-Mn intermetallic compound present in the grain of the aluminum fine crystal grain, for example, a first nanoparticle having a particle diameter of 500 nm or less and An aluminum alloy conductor formed of an Al-Mn intermetallic compound present at the grain boundary of the aluminum fine crystal grains, for example, a nanoparticle dispersed structure having second nanoparticles having a particle diameter of 500 nm or less. Is formed. The Al—Mn intermetallic compound refers to, for example, Al ₆ Mn.

Since the metal structure of the aluminum alloy conductor is composed of aluminum fine crystal grains, the extensibility is improved, and even if bending is repeatedly applied to the metal structure, strain is hardly accumulated and fatigue cracks are not easily generated. Even if a fatigue crack is generated, if the fatigue crack propagates through the grain boundary of the aluminum fine crystal grain, the fatigue crack is deflected and branched along the grain boundary. Therefore, when a fatigue crack collides with the second nanoparticle, deflection and branching of the fatigue crack occur. On the other hand, when the fatigue crack propagates in the aluminum fine crystal grains, the first nanoparticles are dispersed in the aluminum fine crystal grains, so that the fatigue crack collides with the first nanoparticles. Fatigue crack deflection and bifurcation occur. Thereby, the growth rate of fatigue cracks is reduced. As a result, the bending resistance of the aluminum alloy conductor is improved, and the aluminum alloy conductor can be used for wiring in a driving environment such as vibration or bending or in a vibration state.

The cast aluminum body contains a manganese ingot with a purity of 99.9% by mass (the balance is an inevitable impurity) and a manganese ingot with a purity of 99% by weight (the balance is an inevitable impurity). A compound having a rate of 0.6% by mass to 2.5% by mass is prepared. The compound is dissolved at 780 to 830 ° C. and then cooled. Here, the reaction composition in which a eutectic reaction occurs between aluminum and manganese is such that the amount of manganese added to aluminum is 2% by mass, so the content of manganese relative to aluminum is 0.6% by mass or more and less than 2% by mass. When the melt of the hypoeutectic alloy composition is cooled, when the temperature of the melt passes the liquidus temperature, an aluminum-based solid solution primary crystal in which manganese is dissolved in aluminum is formed in the melt, and When the cooling proceeds and the temperature reaches the eutectic temperature (658 ° C.), the dissolved material is in a mixed state of a liquid phase of the primary crystal and the eutectic composition. The liquid phase having the eutectic composition is solidified at a temperature just below the eutectic temperature to form a eutectic structure (a complex structure of aluminum and an Al—Mn intermetallic compound). As a result, the cast structure of the aluminum cast body is in a state in which a eutectic structure exists between the primary crystal grains.

On the other hand, when cooling a melt having a eutectic alloy composition in which the manganese content relative to aluminum is 1.8% by mass, the melt solidifies at a temperature immediately below the eutectic temperature, and the eutectic structure is reduced. Form. As a result, the cast structure of the aluminum casting is composed of a eutectic structure.
Moreover, when cooling the melt | dissolution of the hypereutectic alloy composition whose content rate of manganese with respect to aluminum exceeds 2 mass% and is 2.5 mass% or less, when the temperature of a melt passes liquid phase temperature, When a crystallized product of Al ₆ Mn is formed and the cooling further proceeds and the temperature reaches the eutectic temperature, the dissolved material is in a mixed state of the crystallized product and a liquid phase of the eutectic composition. The liquid phase having the eutectic composition is solidified at a temperature just below the eutectic temperature to form a eutectic structure. As a result, the cast structure of the aluminum cast body is in a state in which crystallized substances are dispersed in the eutectic structure.

When the melt is cooled, if a temperature difference (cooling rate distribution) occurs in the melt, primary crystals are generated in a region where solidification has progressed rapidly. For this reason, in the case of a melt having a eutectic alloy composition, if the temperature of the melt as a whole decreases to just below the eutectic temperature, the liquid phase of the eutectic composition solidifies to form a eutectic structure. The cast structure is in a state where primary crystals are scattered in the eutectic structure. In the case of a melt having a hypereutectic alloy composition, when the temperature of the entire melt passes the liquidus temperature, a crystallized product of an Al-Mn intermetallic compound is further generated in the melt, and the eutectic is obtained. When the temperature is reached, the melt becomes a mixed state of the primary phase, the crystallized product, and the liquid phase of the eutectic composition, and the liquid phase of the eutectic composition is solidified at a temperature just below the eutectic temperature. In order to form a structure, the cast structure of the aluminum cast body is in a state in which a primary crystal, a eutectic structure, and a crystallized substance coexist.

When a workpiece made from an aluminum casting is repeatedly subjected to strong processing by the HPT method, dislocations accumulate in the aluminum crystal grains (primary crystal, aluminum portion in the eutectic structure) in the cast structure of the workpiece. When the sub-crystal grain boundaries are formed and the sum of the equivalent strains introduced into the workpiece reaches 100 or more, the crystal grains become ultrafine through the sub-crystal grain boundaries. On the other hand, in Al-Mn intermetallic compounds (Al-Mn intermetallic compounds in eutectic structures, crystallized products), fine fragmentation and dispersion of Al-Mn intermetallic compounds (partial) by repeated strong processing. Forms solid solution in aluminum crystal grains as manganese.

Here, before carrying out strong processing, plastic deformation processing with an equivalent strain of 2 or less may be applied to the workpiece. When plastic deformation is performed on the work piece with an equivalent strain of 2 or less, the eutectic structure in the work piece is roughly aligned, that is, the eutectic structure is a layered aluminum portion and a layered Al-Mn intermetallic compound portion. Can be stacked alternately. Thereby, in the eutectic structure, the Al—Mn intermetallic compound part is deformed by being pulled by the deformation of the aluminum part, so that the eutectic structure is easily collapsed. As a result, the division of the Al—Mn intermetallic compound portion in the cast structure is promoted, and the Al—Mn intermetallic compound can be dispersed more efficiently.

As a result, at the end of the strong processing, for example, it is composed of an aluminum fine crystal grain having a particle size of 800 nm or less and an Al-Mn intermetallic compound present in the aluminum fine crystal grain. A nanoparticle-dispersed structure comprising the following first nanoparticles and an Al—Mn intermetallic compound existing at the grain boundary of aluminum fine crystal grains, for example, second nanoparticles having a particle size of 500 nm or less. As a result, an aluminum alloy conductor is formed.

Here, when the manganese content in the aluminum casting exceeds the solid solution limit, the manganese content in the aluminum fine crystal grains formed during the strong processing gradually increases by repeating strong processing. At the end of the strong processing, the manganese content in the aluminum fine crystal grains is in a supersaturated state. For this reason, the aluminum alloy conductor obtained by strong processing is heat-treated at a temperature of 300 ° C. or lower in an inert atmosphere (for example, in an argon gas atmosphere), thereby preventing grain growth of aluminum fine crystal grains, The supersaturated manganese in the aluminum fine crystal grains can be precipitated as an Al-Mn intermetallic compound to form second nanoparticles, and the amount of manganese solid solution in the aluminum fine crystal grains can be reduced. . As a result, the electrical conductivity at room temperature of the aluminum alloy conductor can be 50% IACS or more. If the heat treatment temperature exceeds 300 ° C., the growth of aluminum fine crystal grains becomes remarkable and the formed microstructure is broken, which is not preferable. On the other hand, as the heat treatment temperature is lowered, the treatment time required for the heat treatment is drastically increased and the productivity is lowered. For this reason, the minimum of practical heat processing temperature is about 150 degreeC, for example, and processing time will be 0.2 to 40 hours.

Further, when the content of manganese in the aluminum casting exceeds the solid solution limit, it is possible to heat-treat the workpiece at a temperature of 300 ° C. or less during the strong processing. As a result, while preventing the growth of aluminum fine crystal grains formed during strong processing, even if the manganese content dissolved in the aluminum fine crystal grains gradually increases by repeating strong processing, aluminum The Al—Mn intermetallic compound can be precipitated in the fine crystal grains to form second nanoparticles, and the amount of manganese solid solution in the aluminum fine crystal grains can be reduced. As a result, the electrical conductivity at room temperature of the aluminum alloy conductor can be 50% IACS or more. In addition, since the workpiece generates heat during processing (generation of frictional heat) during strong processing, it is necessary to control the heating so that the temperature of the workpiece 10 is 300 ° C. or less. When the temperature of the workpiece exceeds 300 ° C. during strong processing, formation of aluminum fine crystal grains and grain growth of aluminum fine crystal grains proceed simultaneously, and a fine structure can be efficiently formed in the workpiece. Can not. On the other hand, when the temperature of the workpiece is too low during strong processing, for example, when the temperature of the workpiece is less than 150 ° C., the Al—Mn intermetallic compound that forms nanoparticles in the aluminum fine crystal grains Since the deposition rate is reduced and the formation of the second nanoparticles cannot be efficiently performed during strong processing, it is necessary to heat the workpiece 10 so that the temperature of the workpiece 10 is 150 to 300 ° C.

Further, the work piece may be subjected to heat treatment in advance at a temperature of 300 ° C. or less and then subjected to strong processing. By performing the heat treatment, the cooling strain introduced into the workpiece can be removed while preventing the growth of aluminum crystal grains constituting the cast structure of the workpiece. Thereby, the strong processing of an aluminum casting can be performed efficiently. If the heat treatment temperature exceeds 300 ° C, grain growth occurs in the crystal grains and Al-Mn intermetallic compound precipitates that make up the workpiece, and the microstructure is effectively refined by strong processing Can not. Here, when the heat treatment temperature is lowered, the treatment time required for the heat treatment is drastically increased and the productivity is lowered. Therefore, the practical lower limit of the heat treatment temperature is, for example, about 150 ° C. 2 to 40 hours.

The ratio of the first and second nanoparticles constituting the nanoparticle dispersed structure of the aluminum alloy conductor depends on the amount of Al-Mn intermetallic compound crystallized material in the aluminum casting, The amount of product present is determined by the manganese content in the melt. Here, by containing at least 0.3% by mass of manganese with respect to aluminum, the first and second nanoparticles exist in the grains of the aluminum fine crystal grains and the grain boundaries, respectively, and fatigue crack deflection is caused. And branching can occur. And by containing at least 0.6 mass% of manganese with respect to aluminum, the deflection | deviation of a fatigue crack and generation | occurrence | production of a branch can be made remarkable.

On the other hand, the particle size of the first and second nanoparticles depends on the fine cutting efficiency of the Al—Mn intermetallic compound by strong processing, and the dispersion state of the first and second nanoparticles is formed by strong processing. It depends on the dispersion efficiency of the finely divided material. For this purpose, it is preferable that the particle size of the Al—Mn intermetallic compound present in the aluminum casting is small. Here, the grain size of the Al—Mn intermetallic compound in the cast structure is generally larger in the crystallized product than the Al—Mn intermetallic compound portion in the eutectic structure. In order to reduce the particle size of the crystallized product, it is necessary to reduce the difference between the crystallized product start temperature and the eutectic temperature. The crystallized product start temperature is the manganese content in the melt. Determined by.

Therefore, the aluminum castings produced by cooling the hypereutectic alloy compositions having various manganese contents were subjected to strong processing with an equivalent strain of 100 or more, respectively, and the fractionation efficiency and dispersion efficiency of the crystallized product When the manganese content with respect to aluminum is 5% by mass or less, the crystallized product is finely divided into particles having a particle size of 500 nm or less by strong processing having an equivalent strain of 100 or more. It was confirmed that the first and second nanoparticles can be dispersed in the inner and grain boundaries, respectively. For this reason, the range of manganese content with respect to aluminum was defined as 0.3 mass% or more, preferably 0.6 mass% or more and 2.5 mass% or less.
In addition, when manganese content with respect to aluminum exceeds 2.5 mass%, even if it refines | miniaturizes a crystallization thing, a thing with a particle size exceeding 500 nm exists. Since these particles act as defects, they cause, for example, a decrease in tensile strength, a decrease in bending resistance, and a disconnection during wire drawing.

Here, in order to achieve fine cutting and dispersion of Al-Mn intermetallic compounds with high efficiency and high precision by strong processing, in the cast structure of an aluminum cast body, Al-Mn intermetallic compounds It is preferable that the particle size of the material is small and is uniformly dispersed in the cast structure. Such a cast structure is obtained when the melt has a eutectic alloy composition. Therefore, aluminum alloys produced by cooling various compositions having manganese contents from the hypoeutectic alloy composition side to the hypereutectic alloy composition side, centering on the eutectic alloy composition, each have an equivalent strain. When micro-cutting efficiency and dispersion efficiency of the crystallized product were observed under a microscope by performing strong processing of 100 or more, Al was as strong as the case of a cast structure having a eutectic alloy composition by strong processing of equivalent strain of 100 or more. -Mn-based intermetallic compounds can be finely divided into particles having a particle size of 500 nm or less, and dispersed in the aluminum fine crystal grains and in the grain boundaries as first and second nanoparticles, respectively. It was confirmed that the content of was in the range of 0.6 mass% to 2.5 mass%.

Next, examples and comparative examples performed for confirming the effects of the present invention will be described below.
(Examples 1-12)
Aluminum castings 1 to 6 containing 0.3% by mass, 0.6% by mass, 1.5% by mass, 2% by mass, 2.5% by mass, and 5% by mass of iron are cast, and each aluminum casting Disk-shaped workpieces 1 to 6 each having a diameter of 10 mm and a thickness of 1 mm were produced from the bodies 1 to 6. Next, the workpieces 1 to 6 are sandwiched between the upper anvils shown in FIG. 1 and the lower anvil is rotated a predetermined number of times with respect to the upper anvil while applying a pressure of 6 GPa to the workpieces 1 to 6. By introducing shear strain into the workpieces 1 to 6, strong processing with an equivalent strain of 100 is performed, respectively, and the disk-shaped aluminum alloy conductors 1 to 6 are respectively subjected to strong processing with an equivalent strain of 150. Thus, disk-shaped aluminum alloy conductors 7 to 12 were produced. Since the amount of shear strain introduced into the workpieces 1 to 6 varies depending on the distance from the center of the workpieces 1 to 6, test pieces for each evaluation are previously placed in the workpieces 1 to 6. Each region to be taken out was set, and the number of rotations of the lower anvil was set in this region so that strong processing with at least equivalent strain of 100 and 150 was performed.

From the produced aluminum alloy conductors 1 to 12, tensile test pieces 1 to 12 and wire base materials 1 to 12 for producing conductor wires were produced, respectively. Here, the tensile test piece was produced so that the center of the gauge part having a gauge length of 1.5 mm and a gauge width of 0.7 mm was located at a position 2 mm from the center of the aluminum alloy conductors 1 to 12. In addition, the wire base materials 1 to 12 have an open ring shape with an inner diameter of 9 mm and an outer diameter of 10 mm produced by matching the center position with the center of the aluminum alloy conductors 1 to 12, and the center in the width direction along the circumferential direction. The center line which passes was produced so that it might correspond to the circle | round | yen with a radius of 9.5 mm centering on the center of the aluminum alloy conductors 1-12. Then, the wire base materials 1 to 12 are swaged to form a wire with a wire diameter of 1 mm, and the die wire drawing is performed to produce conductor wires 1 to 12 with a wire diameter of 80 μm, respectively. A twisted wire was formed using each of the obtained conductor wires 1 to 12 to produce electric wires 1 to 12 having a cross-sectional area of 0.2 mm ² .

And the tensile test was done at normal temperature using the tensile test pieces 1-12, and the tensile strength was calculated | required. In addition, the electrical conductivity was measured using the produced conductor wires 1 to 12, respectively, and then the bending radius was 15 mm and the bending angle range was ± 90 degrees with a load of 100 g applied to the wires 1 to 12, respectively. The number of breaks was determined by conducting a bending test in which left and right repeated bending was performed at room temperature. Furthermore, a sample for a transmission electron microscope is prepared from each of the tensile test pieces 1 to 12 after the tensile test, the structure of the aluminum alloy conductors 1 to 12 is observed, and the maximum grain size of the aluminum fine crystal grains present in the visual field, The maximum particle sizes of the first and second nanoparticles present in the field of view were determined. Table 1 shows the obtained tensile strength, number of breaks, electrical conductivity, maximum particle size of the aluminum fine crystal grains, maximum particle size of the first nanoparticles, and maximum particle size of the second nanoparticles, respectively.

(Comparative Examples R1 to R6)
The disk-shaped aluminum alloy conductors 1 to 6 produced in Examples 1 to 12 were each subjected to strong processing with an equivalent strain of 50 on the workpieces 1 to 6, thereby forming the disk-shaped aluminum alloy conductors. R1 to R6 were prepared. Next, tensile test pieces R1 to R6 and conductor strands R1 to R6 were respectively produced from the produced aluminum alloy conductors R1 to R6 in the same manner as in Examples 1 to 12, and further, the conductor strands R1 to R6 were cut off. Electric wires R1 to R6 having an area of 0.2 mm ² were produced. And the tensile test was done at normal temperature using tensile test piece R1-R6, and the tensile strength was calculated | required. Moreover, electrical conductivity was measured using produced conductor strand R1-R6, respectively, Then, the bending test was done with respect to electric wire R1-R6 at normal temperature similarly to Examples 1-12, and the frequency | count of a fracture | rupture was calculated | required. Further, a specimen for a transmission electron microscope is prepared from each of the tensile test pieces R1 to R6 after the tensile test, the structure of the aluminum alloy conductors R1 to R6 is observed, and the maximum grain size of the aluminum fine crystal grains existing in the field of view, The maximum particle sizes of the first and second nanoparticles present in the field of view were determined. Table 1 shows the obtained tensile strength, number of breaks, electrical conductivity, maximum particle size of the aluminum fine crystal grains, maximum particle size of the first nanoparticles, and maximum particle size of the second nanoparticles, respectively.

From the results shown in Table 1, an aluminum alloy conductor having a nanoparticle-dispersed structure formed by subjecting an aluminum casting containing 0.3% by mass or more and 5% by mass or less of iron to a strong processing having an equivalent strain of 100 or more, The aluminum fine crystal grains have a particle size of 800 nm or less, the first and second nanoparticles have a particle size of 500 nm or less, the tensile strength at the time of the tensile test at room temperature is 300 MPa or more, and the number of breaks by the repeated bending test at room temperature. 3 million times or more, it can be confirmed that the electrical conductivity at room temperature is 50% IACS or more.
Therefore, if the electric wire produced using this aluminum alloy conductor is used for wiring of the drive part of an industrial robot, for example, the reliability of the robot can be improved and the maintenance burden can be reduced.

(Examples 13 to 15)
Aluminum castings 13 to 15 each containing 0.3% by mass, 2% by mass, and 5% by mass of iron are cast, and each of the aluminum castings 13 to 15 has a disk shape of 10 mm in diameter and 1 mm in thickness. Articles 13 to 15 were prepared and heat-treated at a temperature of 250 ° C. for 0.2 hours in an argon gas atmosphere. Next, the workpieces 13 to 15 were each subjected to strong processing with an equivalent strain of 100 in the same manner as in Examples 1 to 12 to produce disk-shaped aluminum alloy conductors 13 to 15. Tensile test pieces 13 to 15 and conductor strands 13 to 15 were respectively produced from the produced aluminum alloy conductors 13 to 15 in the same manner as in Examples 1 to 12, and the conductor strands 13 to 15 had a cross-sectional area. 0.2 mm ² of electric wires 13 to 15 were produced. And the tensile test was done at normal temperature using the tensile test pieces 13-15, and the tensile strength was calculated | required. Moreover, electrical conductivity was respectively measured using the produced conductor strands 13-15, and the bending test was done with respect to the electric wires 13-15 at normal temperature similarly to Examples 1-12, and the frequency | count of a fracture | rupture was calculated | required. Furthermore, using the tensile test pieces 13 to 15 after the tensile test, the maximum particle diameter of the aluminum fine crystal grains and the maximum particle diameters of the first and second nanoparticles were determined in the same manner as in Examples 1 to 12, respectively. Table 2 shows the obtained tensile strength, number of breaks, electrical conductivity, maximum particle size of the aluminum fine crystal grains, maximum particle size of the first nanoparticles, and maximum particle size of the second nanoparticles, respectively.

(Comparative Examples R13 to R15)
Disk-shaped workpieces R13 to R15 each having a diameter of 10 mm and a thickness of 1 mm were produced from the aluminum castings 13 to 15 produced in Examples 13 to 15, and were subjected to 0.2 hours at 350 ° C. in an argon gas atmosphere. The heat treatment was performed. Next, the workpieces R13 to R15 were each subjected to strong processing with an equivalent strain of 100 in the same manner as in Examples 1 to 12, thereby producing disk-shaped aluminum alloy conductors R13 to R15. Tensile test pieces R13 to R15 and conductor strands R13 to R15 were respectively produced from the produced aluminum alloy conductors R13 to R15 in the same manner as in Examples 1 to 12, and the conductor strands R13 to R15 had a cross-sectional area. Electric wires R13 to R15 of 0.2 mm ² were produced. And the tensile test was done at normal temperature using tensile test piece R13-R15, and the tensile strength was calculated | required. Moreover, electrical conductivity was measured using produced conductor element | wire R13-R15, respectively, Then, the bending test was done with respect to electric wire R13-R15 at normal temperature similarly to Examples 1-12, and the frequency | count of a fracture | rupture was calculated | required. Furthermore, using the tensile test pieces R13 to R15 after the tensile test, the maximum particle diameter of the aluminum fine crystal grains and the maximum particle diameters of the first and second nanoparticles were determined in the same manner as in Examples 1 to 12, respectively. Table 2 shows the obtained tensile strength, number of breaks, electrical conductivity, maximum particle size of the aluminum fine crystal grains, maximum particle size of the first nanoparticles, and maximum particle size of the second nanoparticles, respectively.

From the results shown in Table 2, it can be seen that the tensile strength, the number of breaks, and the conductivity of the aluminum alloy conductors 13 to 15 are improved when heat-treated at a temperature of 300 ° C. or lower before the workpieces 13 to 15 are strongly processed. . This is because heat treatment at 300 ° C. or lower can prevent grain growth of the crystal grains forming the cast structure of the aluminum cast bodies 13 to 15 and remove strain existing in the crystal grains. In addition, by improving the extensibility of the aluminum castings 13 to 15, strong processing is efficiently performed to form aluminum fine crystal grains, and finely severing and dispersing the Al—Fe intermetallic compound. It is understood that the formation of the iron supersaturated solid solution phase was promoted.

(Examples 16 to 33)
An aluminum cast body containing 0.3% by mass of iron was cast, and six cylindrical objects having a diameter of 10 mm and a length of 50 mm were produced from the aluminum cast body, and equivalent strains of 0.2, 0.5, 0 by the ECAP method were produced. .9, 2, 3, and 10 were respectively subjected to plastic deformation, and then formed into a disk shape having a diameter of 10 mm and a thickness of 1 mm to produce workpieces 16 to 21. Next, after performing heat treatment at a temperature of 250 ° C. for 0.2 hours in an argon gas atmosphere, the workpieces 16 to 21 are subjected to strong processing in which the equivalent strain becomes 100 in the same manner as in Examples 1 to 12. The disc-shaped aluminum alloy conductors 16 to 21 were produced. Tensile test pieces 16 to 21 and conductor strands 16 to 21 were respectively produced from the produced aluminum alloy conductors 16 to 21 in the same manner as in Examples 1 to 12, and the conductor strands 16 to 21 had a cross-sectional area. Electric wires 16 to 21 of 0.2 mm ² were produced. And the tensile test was done at normal temperature using the tensile test pieces 16-21, and the tensile strength was calculated | required. Moreover, electrical conductivity was measured using the produced conductor strands 16-21, respectively, Then, the bending test was done with respect to the electric wires 16-21 at normal temperature similarly to Examples 1-12, and the frequency | count of a fracture | rupture was calculated | required. Further, using the tensile test pieces 16 to 21 after the tensile test, the maximum particle diameter of the aluminum fine crystal grains and the maximum particle diameters of the first and second nanoparticles were determined in the same manner as in Examples 1 to 12, respectively. Table 3 shows the obtained tensile strength, number of breaks, electrical conductivity, maximum particle size of the aluminum fine crystal grains, maximum particle size of the first nanoparticles, and maximum particle size of the second nanoparticles, respectively.

An aluminum cast body containing 2% by mass of iron was cast, and aluminum alloy conductors 22 to 27 were produced by the same method as that for producing aluminum alloy conductors 16 to 21. And the tensile test pieces 22-27 and the conductor strands 22-27 are each produced from the aluminum alloy conductors 22-27 similarly to Examples 1-12, Furthermore, cross-sectional area is further from the conductor strands 22-27. 0.2 mm ² of electric wires 22 to 27 were produced. And the tensile test was done at normal temperature using the tensile test pieces 22-27, and the tensile strength was calculated | required. Moreover, electrical conductivity was measured using the produced conductor strands 22-27, respectively, and the bending test was then performed on the wires 22-27 at room temperature in the same manner as in Examples 1-12 to determine the number of breaks. Furthermore, using the tensile test pieces 22 to 27 after the tensile test, the maximum particle diameter of the aluminum fine crystal grains and the maximum particle diameters of the first and second nanoparticles were determined in the same manner as in Examples 1 to 12, respectively. Table 3 shows the obtained tensile strength, number of breaks, electrical conductivity, maximum particle size of the aluminum fine crystal grains, maximum particle size of the first nanoparticles, and maximum particle size of the second nanoparticles, respectively.

Aluminum alloy conductors 28 to 33 were produced in the same manner as in the case of producing aluminum alloy conductors 16 to 21 by casting an aluminum cast body containing 5% by mass of iron. And the tensile test pieces 28-33 and the conductor strands 28-33 are each produced from the aluminum alloy conductors 28-33 similarly to Examples 1-12, Furthermore, cross-sectional area is from the conductor strands 28-33. 0.2 mm ² of electric wires 28 to 33 were produced. And the tensile test was done at normal temperature using the tensile test pieces 28-33, and the tensile strength was calculated | required. Moreover, electrical conductivity was measured using the produced conductor strands 28-33, respectively, and then the bending test was performed on the wires 28-33 at room temperature in the same manner as in Examples 1-12 to determine the number of breaks. Furthermore, using the tensile test pieces 28 to 33 after the tensile test, the maximum particle diameter of the aluminum fine crystal grains and the maximum particle diameters of the first and second nanoparticles were determined in the same manner as in Examples 1 to 12, respectively. Table 3 shows the obtained tensile strength, number of breaks, electrical conductivity, maximum particle size of the aluminum fine crystal grains, maximum particle size of the first nanoparticles, and maximum particle size of the second nanoparticles, respectively.

As shown in Table 3, the second nanometer is obtained when the plastic deformation process with an equivalent strain of 0.5 is performed in advance, as compared with the case of performing a strong process with an equivalent strain of 100 without performing the plastic deformation process (Example 14). When the maximum grain size of the particles is reduced by a plastic deformation process with an equivalent strain of 0.9 in advance, the maximum grain size of each of the aluminum microcrystals, the first nanoparticles, and the second nanoparticles is reduced. When the plastic deformation processing of No. 2 was performed, a decrease in the maximum particle size of the first nanoparticles could be confirmed. And the improvement of the tensile strength was able to be confirmed with refinement | miniaturization of each maximum particle size of the 1st nanoparticle and the 2nd nanoparticle.
Here, as compared with Example 14, even when plastic deformation with an equivalent strain of 0.2 was performed in advance, a decrease in the maximum particle size of the first nanoparticles and the second nanoparticles was not confirmed, and the equivalent strain Even if a plastic deformation process of 0.2 or less is performed, in order to roughly align the eutectic structure in the aluminum casting (to make the eutectic structure easy to collapse), the plastic deformation process applied before the strong process is performed. It was found that the equivalent strain needs to be 0.5 or more.
In addition, even if plastic deformation processing with an equivalent strain of 3 or more is performed in advance, a decrease in the maximum particle size of the first nanoparticles and the second nanoparticles is not confirmed, which is equivalent to the plastic deformation processing applied before performing strong processing. It was found that the strain needs to be 2 or less. In addition, when plastic deformation processing with an equivalent strain of 3 or more is performed, the maximum particle size of the first nanoparticles and the second nanoparticles does not decrease even when strong processing is performed. It is understood that the Al—Fe-based intermetallic compound portion in the structure was refined halfway and became difficult to collapse during strong processing.

(Examples 34 to 36)
Aluminum castings 34 to 36 each containing 0.6% by mass, 2% by mass, and 2.5% by mass of manganese are cast, and each of the aluminum castings 34 to 36 has a disk shape with a diameter of 10 mm and a thickness of 1 mm. The workpieces 34 to 36 were prepared. Next, the workpieces 34 to 36 are sandwiched between the upper anvils shown in FIG. 1 and the lower anvil is rotated a predetermined number of times with respect to the upper anvils while applying a pressure of 6 GPa to the workpieces 34 to 36. Each of the workpieces 34 to 36 was subjected to a strong processing with an equivalent strain of 100 by introducing a shear strain, followed by a heat treatment at a temperature of 250 ° C. for 0.2 hours in an argon gas atmosphere. Aluminum alloy conductors 34 to 36 were produced. Since the amount of shear strain introduced into the workpieces 34 to 36 varies depending on the distance from the center of the workpieces 34 to 36, test pieces for each evaluation are previously placed in the workpieces 34 to 36. Each region to be taken out was set, and the number of rotations of the lower anvil was set in this region so that strong machining with at least an equivalent strain of 100 was performed.

From the produced aluminum alloy conductors 34 to 36, tensile test pieces 34 to 36 and wire base materials 34 to 36 for producing conductor strands were produced, respectively. Here, the tensile test piece was produced so that the center of the gauge part having a gauge length of 1.5 mm and a gauge width of 0.7 mm was located at a position 2 mm from the center of the aluminum alloy conductors 34 to 36. Further, the wire base materials 34 to 36 have an open annular shape with an inner diameter of 9 mm and an outer diameter of 10 mm produced by matching the center positions with the centers of the aluminum alloy conductors 34 to 36, and the central portion in the width direction along the circumferential direction. The center line which passes was produced so that it might correspond to the circle | round | yen with a radius of 9.5 mm centering on the center of the aluminum alloy conductors 34-36. Then, the wire base materials 34 to 36 are swaged to form a wire having a wire diameter of 1 mm, and the die wire drawing is performed to produce conductor wires 34 to 36 having a wire diameter of 80 μm. Wire strands were formed using the obtained conductor wires 34 to 36, respectively, and electric wires 34 to 36 having a cross-sectional area of 0.2 mm ² were produced.

And the tensile test was done at normal temperature using the tensile test pieces 34-36, and the tensile strength was calculated | required. In addition, the electrical conductivity was measured using the produced conductor wires 34 to 36, and then the bending radius was 15 mm and the bending angle range was ± 90 degrees with a load of 100 g applied to the wires 34 to 36, respectively. The number of breaks was determined by conducting a bending test in which left and right repeated bending was performed at room temperature. Further, a specimen for a transmission electron microscope is prepared from each of the tensile test pieces 34 to 36 after the tensile test, the structure of the aluminum alloy conductors 34 to 36 is observed, and the maximum grain size of the aluminum fine crystal grains existing in the field of view, The maximum particle sizes of the first and second nanoparticles present in the field of view were determined. Table 4 shows the obtained tensile strength, number of breaks, electrical conductivity, maximum particle size of the aluminum fine crystal grains, maximum particle size of the first nanoparticles, and maximum particle size of the second nanoparticles, respectively.

(Comparative Examples R34 to R36)
The disk-shaped aluminum alloy conductors 34 to 36 produced in Examples 34 to 36 were each subjected to strong processing with an equivalent strain of 50 on the workpieces 34 to 36 to obtain disk-shaped aluminum alloy conductors. R34 to R36 were produced. Next, tensile test pieces R34 to R36 and conductor strands R34 to R36 were respectively produced from the produced aluminum alloy conductors R34 to R36 in the same manner as in Examples 34 to 36, and further, the conductor strands R34 to R36 were cut off. Electric wires R34 to R36 having an area of 0.2 mm ² were produced. And the tensile test was done at normal temperature using tensile test piece R34-R36, and the tensile strength was calculated | required. Moreover, electrical conductivity was measured using the produced conductor strands R34 to R36, respectively, and then bending tests were performed on the wires R34 to R36 at room temperature in the same manner as in Examples 34 to 36 to determine the number of breaks. Further, a specimen for a transmission electron microscope is prepared from each of the tensile test pieces R34 to R36 after the tensile test, and the structure of the aluminum alloy conductors R34 to R36 is observed, and the maximum grain size of the aluminum fine crystal grains existing in the field of view, The maximum particle sizes of the first and second nanoparticles present in the field of view were determined. Table 4 shows the obtained tensile strength, number of breaks, electrical conductivity, maximum particle size of the aluminum fine crystal grains, maximum particle size of the first nanoparticles, and maximum particle size of the second nanoparticles, respectively.

(Examples 37 to 40)
Aluminum castings 37 to 40 each containing 0.3% by mass, 0.7% by mass, 2% by mass, and 2.5% by mass of chromium were cast, and each aluminum casting 37 to 40 had a diameter of 10 mm and a thickness. Disk-shaped workpieces 37 to 40 having a thickness of 1 mm were produced. Next, the workpieces 37 to 40 are sandwiched between the upper anvils shown in FIG. 1, and the lower anvil is rotated with respect to the upper anvil a predetermined number of times while applying a pressure of 6 GPa to the workpieces 37 to 40. After introducing a shear strain into the workpieces 37 to 40 and performing strong processing each having an equivalent strain of 100, a heat treatment is performed at a temperature of 250 ° C. for 0.2 hours in an argon gas atmosphere. Aluminum alloy conductors 37 to 40 were produced. Since the amount of shear strain introduced into the workpieces 37 to 40 varies depending on the distance from the center of the workpieces 37 to 40, test pieces for each evaluation are previously placed in the workpieces 37 to 40. Each region to be taken out was set, and the number of rotations of the lower anvil was set in this region so that strong machining with at least an equivalent strain of 100 was performed.

From the produced aluminum alloy conductors 37 to 40, tensile test pieces 37 to 40 and wire base materials 37 to 40 for producing conductor wires were produced, respectively. Here, the tensile test piece was produced so that the center of the gauge part having a gauge length of 1.5 mm and a gauge width of 0.7 mm was located at a position 2 mm from the center of the aluminum alloy conductors 37 to 40. Further, the wire base materials 37 to 40 are formed in an open ring shape having an inner diameter of 9 mm and an outer diameter of 10 mm, which is produced by matching the center position with the center of the aluminum alloy conductors 37 to 40, and the central portion in the width direction along the circumferential direction. The center line which passes was produced so that it might correspond to the circle | round | yen with a radius of 9.5 mm centering on the center of the aluminum alloy conductors 37-40. Then, a swaging process is performed on the wire base materials 37 to 40 to form a wire with a wire diameter of 1 mm, and a die wire drawing process is performed to produce conductor strands 37 to 40 with a wire diameter of 80 μm. A twisted wire was formed using each of the obtained conductor wires 37 to 40 to produce electric wires 37 to 40 having a cross-sectional area of 0.2 mm ² .

And the tensile test was done at normal temperature using the tensile test pieces 37-40, and the tensile strength was calculated | required. Moreover, the electrical conductivity was measured using the produced conductor wires 37 to 40, respectively, and then the bending radius was 15 mm and the bending angle range was ± 90 degrees with a load of 100 g applied to the wires 37 to 40, respectively. The number of breaks was determined by conducting a bending test in which left and right repeated bending was performed at room temperature. Further, a specimen for a transmission electron microscope is prepared from each of the tensile test pieces 37 to 40 after the tensile test, the structure of the aluminum alloy conductors 37 to 40 is observed, and the maximum grain size of the aluminum fine crystal grains existing in the visual field, The maximum particle sizes of the first and second nanoparticles present in the field of view were determined. Table 5 shows the obtained tensile strength, number of breaks, electrical conductivity, maximum particle diameter of the aluminum fine crystal grains, maximum particle diameter of the first nanoparticles, and maximum particle diameter of the second nanoparticles, respectively.

(Comparative Examples R37 to R40)
The disk-shaped aluminum alloy conductors 37 to 40 produced in Examples 37 to 40 were each subjected to strong processing with an equivalent strain of 50 on the workpieces 37 to 40, so that the disk-shaped aluminum alloy conductors were formed. R37 to R40 were produced. Next, tensile test pieces R37 to R40 and conductor strands R37 to R40 were respectively produced from the produced aluminum alloy conductors R37 to R40 in the same manner as in Examples 37 to 40. Further, the conductor strands R37 to R40 were cut off. Electric wires R37 to R40 having an area of 0.2 mm ² were produced. And the tensile test was done at normal temperature using tensile test piece R37-R40, and the tensile strength was calculated | required. Moreover, electrical conductivity was measured using produced conductor strand R37-R40, respectively, Then, the bending test was done with respect to electric wire R37-R40 at normal temperature similarly to Examples 37-40, and the frequency | count of a fracture | rupture was calculated | required. Further, a specimen for a transmission electron microscope is prepared from each of the tensile test pieces R37 to R40 after the tensile test, the structure of the aluminum alloy conductors R37 to R40 is observed, and the maximum grain size of the aluminum fine crystal grains existing in the field of view, The maximum particle sizes of the first and second nanoparticles present in the field of view were determined. Table 5 shows the obtained tensile strength, number of breaks, electrical conductivity, maximum particle diameter of the aluminum fine crystal grains, maximum particle diameter of the first nanoparticles, and maximum particle diameter of the second nanoparticles, respectively.

From the results shown in Tables 4 and 5, it has a nano-particle dispersed structure formed by subjecting an aluminum casting containing 0.3% by mass or more and 5% by mass or less of manganese or chromium to strong processing with an equivalent strain of 100 or more. The aluminum alloy conductor has a fine aluminum crystal grain size of 800 nm or less, the first and second nanoparticles have a particle size of 500 nm or less, a tensile strength at the time of a tensile test at room temperature of 220 MPa or more, and repeated at room temperature. It can be confirmed that the number of breaks in the bending test is 3 million times or more and the electrical conductivity at room temperature is 50% IACS or more.

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the configuration described in the above-described embodiment, and the matters described in the scope of claims. Other embodiments and modifications conceivable within the scope are also included.
Further, the present invention also includes a combination of components included in the present embodiment and other embodiments and modifications.
In addition, in the above invention, aluminum is naturally applied also when an unavoidable impurity is included.

10: Workpiece, 11, 11a: Dimple, 12: Upper anvil, 13: Lower anvil

Claims (13)

A method of manufacturing an aluminum alloy conductor that is commonly used in a vibration or bending drive environment or vibration state,
An intermetallic compound is formed with aluminum, and has a reaction composition in which an eutectic reaction or a peritectic reaction occurs in a region where the amount of addition to aluminum is 5% by mass or less. The aluminum casting containing element X, which is less than 0.3% by mass to 5% by mass, is subjected to strong processing with a total sum of equivalent strains of 100 or more. A first nanoparticle composed of a fine crystal grain, the intermetallic compound existing in a grain of the aluminum fine crystal grain, and a second nanoparticle composed of the intermetallic compound present in a grain boundary of the aluminum fine crystal grain. Forming a nanoparticle-dispersed tissue having particles ,
According to the repeated bending test at room temperature, the aluminum fine crystal grains have a particle size of 800 nm or less, the first and second nanoparticles have a particle size of 500 nm or less, and the tensile strength at the time of a tensile test at room temperature is 220 MPa or more. A method for producing an aluminum alloy conductor, wherein the number of breaks is 3 million times or more, and the electrical conductivity at room temperature is 50% IACS or more . A method of manufacturing an aluminum alloy conductor that is commonly used in a vibration or bending drive environment or vibration state,
An intermetallic compound is formed with aluminum, and has a reaction composition in which an eutectic reaction or a peritectic reaction occurs in a region where the amount of addition to aluminum is 5% by mass or less. The aluminum casting containing element X, which is less than 0.3% by mass to 5% by mass, is subjected to strong processing with a total sum of equivalent strains of 100 or more. A first nanoparticle composed of a fine crystal grain, the intermetallic compound existing in a grain of the aluminum fine crystal grain, and a second nanoparticle composed of the intermetallic compound present in a grain boundary of the aluminum fine crystal grain. Forming a nanoparticle-dispersed tissue having particles ,
The method for producing an aluminum alloy conductor, wherein the aluminum cast body is heat-treated at a temperature of 300 ° C. or less before or during the strong processing. A method of manufacturing an aluminum alloy conductor that is commonly used in a vibration or bending drive environment or vibration state,
An intermetallic compound is formed with aluminum, and has a reaction composition in which an eutectic reaction or a peritectic reaction occurs in a region where the amount of addition to aluminum is 5% by mass or less. The aluminum casting containing element X, which is less than 0.3% by mass to 5% by mass, is subjected to strong processing with a total sum of equivalent strains of 100 or more. A first nanoparticle composed of a fine crystal grain, the intermetallic compound existing in a grain of the aluminum fine crystal grain, and a second nanoparticle composed of the intermetallic compound present in a grain boundary of the aluminum fine crystal grain. Forming a nanoparticle-dispersed tissue having particles ,
The said aluminum alloy conductor is heat-processed at the temperature of 300 degrees C or less, The manufacturing method of the aluminum alloy conductor characterized by the above-mentioned . In the manufacturing method of the aluminum alloy conductor of any one of Claims 1-3, the said casting structure is 1) the primary crystal of the aluminum-based solid solution in which the said element X was dissolved in aluminum, and between aluminum and the said metal Eutectic structure of compound, 2) eutectic structure of aluminum and intermetallic compound, 3) crystallized product of intermetallic compound, eutectic structure of aluminum and intermetallic compound, and 4) aluminum-based solid solution 1. A method for producing an aluminum alloy conductor, wherein the primary crystal is an eutectic structure of aluminum and the intermetallic compound, or a crystallized product of the intermetallic compound. 5. The method for producing an aluminum alloy conductor according to claim 4 , wherein the aluminum casting is preliminarily subjected to plastic deformation with an equivalent strain of 2 or less. The manufacturing method according to claim 4 or 5 aluminum alloy conductor, wherein the element X is a iron producing method of an aluminum alloy conductor, characterized in that it contains 0.6 wt% to 5 wt% or less of aluminum . 7. The method for producing an aluminum alloy conductor according to claim 6 , wherein iron is contained in an amount of 1.5% by mass to 2.5% by mass with respect to aluminum. The method for producing an aluminum alloy conductor according to claim 6 or 7 , wherein the aluminum casting is cast using one or both of an aluminum ingot and an aluminum recycled material. . 6. The method for producing an aluminum alloy conductor according to claim 5 , wherein the element X is manganese and is contained in the aluminum in an amount of 0.6% by mass to 2.5% by mass. In the manufacturing method of the aluminum alloy conductor of any one of Claims 1-3, the said casting structure | tissue was included in 1) the aluminum base solid solution in which the said element X was dissolved in aluminum, and this aluminum base solid solution. The intermetallic compound, or 2) an aluminum-based solid solution in which the element X is dissolved in aluminum, a crystallized product of the intermetallic compound included in the aluminum-based solid solution, and the intermetallic compound precipitated in the aluminum-based solid solution. A method for producing an aluminum alloy conductor, which is a compound. 11. The method for producing an aluminum alloy conductor according to claim 10 , wherein the element X is chromium and is contained in the aluminum in an amount of 0.6 mass% to 5 mass%. The aluminum alloy conductor according to any one of claims 1 to 11 , wherein the aluminum alloy conductor is formed by drawing at a workability of 5 or more, and a conductor wire having a wire diameter of 0.03 mm to 0.5 mm is used. A method of manufacturing an electric wire characterized by 13. The method of manufacturing an electric wire according to claim 12 , wherein the conductor wire is heat-treated at a temperature of 350 [deg.] C. or less.

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