JP2001234308A - Metallic formed stock and its forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metallic formed stock forming method by which a metal formed stock can easily and efficiently be formed and the shape of the stock to be formed is not limited. SOLUTION: A pin is inserted into a base material, a sliding piece is moved while being slid on the base material, the original crystal grains of the base material are collapsed along the moving path of the sliding piece by plastic fluidity, then are recrystallized, and fine crystal grains are formed. In this way, by the mechanical recrystallization, a fine crystal part 21 where the crystal grains are locally refined is formed. In this metallic formed stock 20, only the fine crystal part 21 exhibits superplasticity, and in the remaining parts 22 and 23, superplasticity is not exhibited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal forming material which can be suitably used for superplastic working and a method for forming the same, and a molding member and a forming method which are formed using the metal forming material.

[0002]

2. Description of the Related Art Structural materials include metal materials and resin-based materials. With the diversification and complexity of structures,
BACKGROUND ART Resin-based materials that can easily form a molded member having a complicated shape are widely used as structural materials. On the other hand, from the viewpoint of environmental issues, there is a demand for further use of a metal material having excellent recyclability as compared with a resin material. As described above, in order to use metal materials more widely as structural materials used for diversified and complicated structures, metal forming materials must have large plastic deformation so that they can be formed into complex shapes. Must be possible.

When a metal material is subjected to an external force at a predetermined temperature and at a predetermined strain rate by refining crystal grains,
It is known to exhibit superplasticity that enables plastic deformation until the elongation reaches several hundred percent. Therefore, by using a metal forming material in which crystal grains are refined, a plastic member having a complicated shape can be formed by largely plastic deformation. Such a metal forming material in which crystal grains are refined is formed by rolling or extruding a base material, crushing the crystal grains, and then recrystallizing the whole with recrystallization or phase transformation. I have.

[0004]

The prior art superplastic metal forming material obtained by rolling or extruding as described above is limited to a plate or a mold material, and the material is carbon steel, titanium material or the like. Or an aluminum alloy containing an alloy component that suppresses recrystallization growth. Also, in superplastic forming, a pressing force is given to a metal forming material by gas while adjusting the gas pressure according to the forming amount (deformation amount) of each part, and the whole is formed into a predetermined shape, but the whole is uniformly crystallized. In a metal forming material having fine grains, it is necessary to restrain a portion that does not need to be deformed during plastic working so that only a portion to be plastically deformed is deformed, and there are cases where forming is difficult.

More specifically, as shown in FIG. 16, an L-shaped forming member 1 can be formed by bending a flat metal forming material 2 at a central portion 3 as shown in FIG. Only the central portion 3 needs to exhibit superplasticity, and the sides 4, 5 on both sides thereof do not need to exhibit superplasticity. When these sides 4 and 5 exhibit superplasticity, it is necessary to prevent the sides 4 and 5 from being deformed, which makes it difficult to adjust the gas pressure or to adjust the load by using another load applying means, and to save time and effort. In such a case, the molding becomes difficult and the molding is troublesome.

Further, as shown in FIG. 17, an L-shaped forming member 7 bent at the center can be formed by bending an L-shaped metal forming material 8 which is an extruded material at the center 9. However, in bending, FIG.
Has the same problems as in the case of the molding shown in FIG. Further FIG.
As shown in FIG. 8, the forming member 10 having a part protruding from the remaining part of the flat plate can be formed by deep drawing a part of the flat metal forming material in one thickness direction. The case also has the same problem as the case of the molding shown in FIG.

Accordingly, an object of the present invention is to provide a metal forming material which can be formed easily and with less trouble, and a method for forming the same.

Another object of the present invention is to provide a method for forming a metal forming material in which the material of the metal forming material to be formed can cover a wider range than before.

Still another object of the present invention is to provide a method for forming a metal molding material in which the shape of the metal molding material to be formed is not limited.

[0010]

According to the first aspect of the present invention, a crystal grain is locally refined, and the crystal grain having the refined crystal grain is superplasticized at a predetermined temperature and a predetermined strain rate. Is a metal forming material characterized by exhibiting the following.

According to the present invention, the fine crystal part in which the crystal grains are refined develops superplasticity at a predetermined temperature and a predetermined strain rate, and the remaining part does not develop superplasticity. In processing, fine work and operation such as using a different force to be applied to each fine region or using a jig for the same so as not to deform the remaining portion are required. Accordingly, the molding can be performed easily and with less labor without requiring any labor and jig for preventing the remaining portion from being deformed.

According to the second aspect of the present invention, a sliding piece is inserted into a base material for forming a metal forming material, and the sliding piece is moved while sliding with respect to the base material, and the sliding piece is moved. The crystal grain is locally refined along the moving path of the moving piece.

According to the present invention, the sliding piece is moved while being slid with respect to the base material, and the crystal grains are locally refined along the moving path of the sliding piece. Superplasticity develops only near the moving path of the moving piece. In the metal forming material, the crystal grains in the remaining portion other than the fine crystal portion are not refined, so that the forming can be performed more easily and the shape can be formed with high precision.

According to a third aspect of the present invention, a base material for forming a metal forming material comprising a metal which undergoes a phase transformation at a transformation point lower than a melting point is heat-treated in a temperature change cycle in which the base material locally passes through the transformation point. Is repeated, and the crystal grains of the heat-treated fine crystal part are refined.

According to the present invention, the heat treatment is repeated in a temperature change cycle in which the base material locally passes through the transformation point, and the crystal grains are locally refined. Express. In the metal forming material, the crystal grains in the remaining portion other than the fine crystal portion are not refined, so that the forming can be performed more easily and the shape can be formed with high precision.

According to a fourth aspect of the present invention, a crystal grain of a base material for forming a metal forming material is locally crushed, and the crystal grain is recrystallized in a crushed crystal part. This is a method for forming a metal forming material to be formed.

According to the present invention, when the crystal grains of the base material are locally crushed, they are recrystallized in the crushed crystal parts, and the recrystallized crystal grains become fine crystal grains. Thereby, crystal grains are locally refined, and this fine crystal part is
Superplasticity can be developed at a predetermined temperature and a predetermined strain rate. Compared with the case where the crystal grains of the entire base material for forming the metal forming material are refined, the processing amount for refining the crystal grains can be reduced. Therefore, the processing can be performed in a short time at a low cost, with a reduced processing time.

According to a fifth aspect of the present invention, a sliding piece is inserted into a base material for forming a metal forming material, and the sliding piece is moved while sliding with respect to the base material. It is characterized in that it is locally recrystallized along the movement path of the piece.

According to the present invention, since the sliding piece is inserted into the base material, moved while sliding, and recrystallized to make crystal grains fine, the base material having the same shape as the metal forming material to be formed is formed. Is prepared, a metal forming material having a required shape and having locally refined crystal grains can be formed without deforming the shape. Therefore, the shape of the metal forming material to be formed is not limited to a flat plate shape, for example, including a cylindrical shape and a rod shape. In addition, since the crystal grains can be refined only by moving the sliding piece while sliding, the metal forming material can be formed by the refinement treatment easily and without using a large-scale apparatus. In addition, the crystal grains can be refined only in the vicinity of the movement path where the sliding piece has been moved, and the crystal grains can be refined only in the region where superplasticity is to be developed. A high-precision metal forming material in which crystal grains in a high region are refined can be formed, and even a metal forming material in which a region where superplasticity is desired to be developed is small can be easily formed. By subjecting the whole to a local fine crystallization process using a sliding piece continuously, it is also possible to obtain a conventional molding material in which the whole is finely crystallized. Furthermore, according to this method, it is possible to easily form them from a magnesium alloy or the like, which has been difficult to refine crystal grains by the conventional method of rolling and extrusion, and the material for forming the metal forming material can be easily formed. The range of application can be widened.

According to a sixth aspect of the present invention, a base material for forming a metal forming material made of a metal which undergoes a phase transformation at a transformation point lower than a melting point is heat-treated in a temperature change cycle in which the base material locally passes through the transformation point. Is repeated to recrystallize in the heat-treated fine crystal part.

According to the present invention, the base material is recrystallized by repeating the heat treatment in a temperature change cycle in which the base material locally passes through the transformation point, and the crystal grains in the fine crystal part are refined. If a base material having the same shape as the material is prepared, a metal forming material having a required shape and locally refined crystal grains can be formed without deforming the shape. Therefore, the shape of the metal forming material to be formed is not limited to a flat plate shape, for example, including a cylindrical shape and a rod shape. Further, since the crystal grains can be refined only by performing the heat treatment, the formation is easy. In addition, the crystal grains can be refined only in the vicinity of the heat-treated area, and the crystal grains can be refined only in the area where superplasticity is to be exhibited. It is possible to form a highly accurate metal forming material. In addition, the heat treatment can be performed over a wide range, and a metal forming material having a wide fine crystal part to exhibit superplasticity can be easily formed.

According to a seventh aspect of the present invention, there is provided a molded member wherein the fine crystal part of the metal forming material according to any one of the first to third aspects is formed by superplastic working.

According to the present invention, since the fine crystal part of the metal forming material that locally exhibits superplasticity is formed by superplastic working, the remaining portion that does not exhibit superplasticity has a precision of not being deformed. Of a molded member having a high hardness can be obtained.

The present invention according to claim 8 is characterized in that the fine crystal part is superplastically worked to form a formed member using the metal forming material according to any one of claims 1 to 3. It is a molding method.

According to the present invention, since the fine crystal part of the metal forming material which locally exhibits superplasticity is superplastically processed and the formed member is formed, the deformation of the remaining part can be easily prevented. The member can be easily formed.

[0026]

FIG. 1 is a perspective view showing a metal forming material 20 according to an embodiment of the present invention. FIG. 2 is a perspective view showing the metal forming material 20 as viewed from a section line II-II in FIG. 3 is a cross-sectional view showing the structure of the fine crystal part 21 shown in FIG.
It is sectional drawing which expands and shows. The metal molding material 20 is a flat plate-shaped material, and is naturally made of metal. The metal is, for example, a light metal or light metal alloy, more specifically, an aluminum alloy (Al5083 or Al606).
1) High strength aluminum alloy (for example, Al7075)
Or an aluminum-lithium alloy (Al-Li209
4). The metal may be titanium or its alloy, other light metal such as magnesium or its alloy, or steel such as carbon steel and stainless steel, instead of aluminum alloy. Or a single element metal other than these and an alloy thereof.

In the metal forming material 20, crystal grains are locally refined, and the crystal grains 2 are refined.
1 is configured to exhibit superplasticity at a predetermined temperature and a predetermined strain rate. As shown in FIG. 2, the crystal grains of the fine crystal part 21 are the remaining parts 22, 23 excluding the fine crystal part.
Finer than In the metal forming material 20, crystal grains are refined in a fine crystal part 21 which is a central part in the width direction X, extends over the entire area in the thickness direction Z, and extends over the entire area in the longitudinal direction Y.
More specifically, the shape of the cross section perpendicular to the longitudinal direction Y of the fine crystal part 21 is substantially uniform in the longitudinal direction Y.
In this example, the width is tapered so that the width on one side in the thickness direction is larger than the width on the other side in the thickness direction, but the cross-sectional shape can be controlled to the same width or the like by a processing method. The width direction X, the longitudinal direction Y, and the thickness direction Z are perpendicular to each other.

The superplasticity is a property that when a strain is generated at a temperature and a strain rate determined by the kind of a metal or the like, it can be plastically deformed until the elongation becomes several hundreds percent. When the temperature and the strain rate are under predetermined conditions, superplasticity is exhibited. In the case where the metal is a high-strength aluminum alloy, when the crystal grains are fine crystal grains having a
Superplasticity is exhibited when the strain rate is about 10 ⁻³ mm / sec at about 00 ° C. In the metal forming material 20, the crystal grains of the fine crystal part 21 have a grain size of 1 μm as shown in FIG. The crystal grains of each of the remaining portions 22 and 23 on both sides are non-fine crystal grains having a particle size that does not exhibit superplasticity even when the fine crystal portion 21 is subjected to superplasticity.

FIG. 4 is a perspective view for explaining a method of forming the metal forming material 20. The metal forming material 20 is locally crushed by the forming method according to the present invention, that is, locally crushes crystal grains of a base material 25 (for convenience, an intermediate product is also described as a base material in the present invention) for forming the metal forming material. Thus, the crystal grains are recrystallized in the crushed crystal portion 26 where the crystal grains are crushed. The crystal grains to be recrystallized become fine crystal grains, and when the recrystallization is completed in the crushed crystal part 26, the fine crystal part 21 is formed to form the metal forming material 20 in which the crystal grains are locally refined. be able to. In the method shown in FIG. 4, a pin 30, which is a sliding piece, is inserted into the base material 25, and the pin 30 is moved while sliding with respect to the base material 25, and is locally moved along the movement path of the pin 30. The crystal grains are crushed and recrystallized in the crushed crystal part 26 to refine the crystal grains.

FIG. 5 shows a rotary sliding member 28 with a pin 30 used in the method of forming the metal forming material 20 shown in FIG.
FIG. The crystal grains of the base material 25 are locally crushed using the rotary sliding member 28. Rotary sliding member 28
Has a substantially cylindrical rotating base 29 and a cylindrical pin 30 provided coaxially with the rotating base 29. The rotating base 29 has an end surface 3 perpendicular to the axis L1 of the rotating sliding member 28.
1 and projecting in the axial direction from the end face 31
0 are integrally formed. Such a rotary sliding member 2
8 can be driven to rotate about the axis L1 by driving means (not shown), can be driven in the axial direction, and can be displaced in the direction perpendicular to the axis L1 and the axis L1.
At least one of the angular displacements about an axis intersecting 1
Two displacements.

Using the rotary sliding member 28, the base material 25
The pin 30 is inserted into the base member 25, and the rotary sliding member 28 is rotated in the rotation direction A about the axis L1 to slide the pin 30 with respect to the base material 25, and is additionally moved in the movement direction B perpendicular to the axis L1. Then, the crystal grains can be locally crushed along the movement path of the pin 30 and recrystallized in the crushed crystal part 26. The mechanism for crushing and recrystallizing the crystal grains is generated by generation of frictional heat due to rotation and plastic working of the surrounding base material. In addition to the pins 30, the end surface 31 of the rotating base 29 may be slid on the base material 25. In FIG. 4, the end face 31 is also slid.

The metal forming material 20 as shown in FIG. 1 is formed by disposing the axis L1 in the thickness direction Z and moving it in the longitudinal direction Y. End surface 31 of rotating base 29 of rotating sliding member 28
Outside diameter D1, outside diameter D2 of pin 30 and pin 30
Is determined as appropriate according to the size of the portion where crystal grains are to be crushed, that is, the size of the fine crystal portion 21 to be formed.

If the outer diameters D1 and D2 are made larger, the width of the fine crystal part 21 becomes larger, and if the outer diameters D1 and D2 are made smaller, the width of the fine crystal part 21 can be made smaller. Increasing the protruding length T1 increases the depth (dimension in the thickness direction) of the fine crystal portion 21, and reducing the protruding length T1 can reduce the depth of the fine crystal portion 21. The protrusion length T1 is preferably such that crystal grains are refined in the entire region in the thickness direction in order to produce a forming material for forming by superplastic processing, and the thickness T2 of the metal forming material 20 to be formed. Is determined almost identically. For example, fine crystal part 2
1 is formed with a maximum width on the side on which the end face 31 slides, the maximum width W1 is about 15 mm, and the minimum width W on the opposite side.
2 is about 10 mm, and the thickness T2 of the metal molding material 20
In forming the metal forming material 20 having a diameter of about 4 to 5 mm, the outer diameter D1 of the rotating base 29 is 15 mmφ,
Has an outer diameter D2 of 10 mm and a protrusion amount T1 of 5 mm.

The rotation speed N and the movement speed V are determined by the metal forming material (base material 25). For example, in the case of a high-strength aluminum alloy, the rotation speed N is 2000 mi.
n ^-1 (2000 rpm) and a moving speed V of 3.3 mm
/ S (200 mm / min). Further, since the rotary sliding member 28 is slidably rotated on the base material 25, the base material 2
5 and a material having a high softening point, for example, alloy steel SK3 or stainless steel SUS630.

FIG. 6 is a flowchart showing the procedure of the forming method shown in FIG. In step s0, a base material 25 having the same shape as the metal forming material 20 to be formed is prepared, and the forming operation is started. Next, in step s1, the rotary sliding member 2
8 is rotated to rotate the pin 30, and the next step s2
Thus, the pin 30 is inserted into the base material 25 with the pin 30 rotated in this manner. The insertion of the pin 30 into the base material 25 is performed by moving the pin 30 in an axial direction or a direction intersecting the axis L1. As shown in FIG. 1, when the metal forming material 20 is formed such that both end portions of the fine crystal portion 21 face the outside at the end face of the metal forming material 20, the base is located upstream of the moving direction B of the moving path of the pin 30. Starting position 3 as shown by a virtual line in FIG.
The pin 30 can be inserted into the base material 25 by arranging the pin 30 at 5 and moving the pin 30 from the movement start position 35 toward the base material 25 in the movement direction B.

More specifically, when the pin 30 is moved toward the base material 25 and the pin 30 contacts the base material 25 (at this time, the end face 31 is also in contact with the base material 25), the pin 30 and the rotating base 29 are rotated. Is slid with respect to the base material, and the frictional heat and deformation heat generated by the sliding cause the portion of the base material 25 in the vicinity of the region where the pin 30 is in contact with the base material to have a softening point, for example, 400 ° C. As described above, the temperature is raised to, for example, about 450 ° C., and this portion is softened. The pin 30 is further moved in the softened state as described above, and the softened base material flows around the pin (plastic flow) due to the rotation of the pin 30 and wraps around in the movement direction B upstream of the pin 30. The pins 30 move into the base material 25 in such a manner as to push the softened base material apart, whereby the pins are inserted into the base material 25.

After the pin 30 is inserted into the base material 25, the rotary sliding member 28 is moved in step s3, whereby the pin 25 moves along a predetermined movement path, in the present embodiment in the longitudinal direction of the base material 25. Is moved with respect to the base material 25 so that the axis L1 moves on a virtual plane 36 perpendicular to the width direction extending in the width direction. The movement of the rotary sliding member 28 including the pin 25 with respect to the base material 25 in step s3 is performed by sliding the pin 30 and the rotation base 29 with the base material 25 as in the case of inserting the pin 30 in step s2. The peripheral portion 38 of the pin 30 is softened, and the softened base material plastically flows and wraps around the pin 30 in the moving direction B upstream.
0 moves in the movement direction B with respect to the base material 25 so as to separate the softened base material.

By moving the pin 30 while sliding, the base material around the pin 30 is mechanically heated,
By softening and mechanically plastically flowing, the original crystal grains of the base material 25 are crushed, and the pins 30 are re-crystallized after flowing around the upstream side in the moving direction of the pins 30. In other words, in the crushed crystal part 26 formed on the upstream side in the moving direction of the pin 30, the base material that has flowed around by plastic flow is recrystallized. In this way, the movement of the pin 30 causes the base material to be locally dynamically recrystallized and thermally recrystallized. Since this recrystallization is performed in a state where the applied strain is very large and cooled by the surrounding base material that is not heated, the crystal grains to be recrystallized become fine crystal grains without growing. In this way, the crystal grains are refined, and fine crystal parts 21 are formed.

In such a step of moving the pin 30,
The rotation speed N and the movement speed V of the pin 30 and the rotary sliding member 28 are mutually related parameters and are determined as appropriate. If the moving speed V is too low for a certain rotation speed N, the base material around the pins 30 will be overheated, wasteful energy will be consumed, and conversely, the moving speed V will be too high. In this case, the heating of the base material around the pins 30 becomes insufficient, so that the crystal grains are crushed and plastic flow cannot be performed. Therefore, the rotation speed N and the movement speed V are determined so that the base material flows in a suitable plastic flow in a state where the base material is heated and heated sufficiently and sufficiently.

After the pin 30 is moved while achieving such a recrystallization action, the pin 30 is separated from the base material 25 while the pin 30 is rotated in step s5. The detachment of the pin 30 from the base material 25 is performed by moving the pin 30 in an axial direction or a direction intersecting the axis L1. As shown in FIG. 1, when the metal forming material 20 is formed such that both end portions of the fine crystal portion 21 face the outside at the end face of the metal forming material 20, the pin 30 is moved downstream in the moving direction B of the moving path of the pin 30. The pin 30 can be disengaged from the base material 25 by moving the pin 30 in the movement direction B to the movement end position 39 as shown by a virtual line in FIG. Also in the detachment process of the pin 30, the base material around the pin 30 is removed at each step s2.
As in the step of inserting the s3 pin and the step of moving the pin, it is plastically flowed and recrystallized to achieve an effect of making crystal grains fine.

Accordingly, the pin 30 is inserted into the base material 25 from the movement start position 35 while rotating, moved with respect to the base material 25, further moved to the movement end position 39, and separated from the base material 25, whereby the base material 25 is removed. Crystal grains can be refined over the entire region in the longitudinal direction of the material 25.

After the pins 30 are detached from the base material 25, the rotation of the rotary sliding member 28 is stopped and the rotation of the pins 30 is stopped in step s5. Stop pin 30
In step s6, the forming operation of the metal forming material 20 ends. Thus, the metal forming material 20 can be formed.

According to such a metal forming material 20, the fine crystal part 21 exhibits superplasticity at a predetermined temperature and a predetermined strain rate, and the remaining parts 22, 23 do not exhibit superplasticity.
When the metal forming material 20 is subjected to plastic working, it is not necessary to devise a device for preventing the remaining portion from being deformed.
For example, there is no need to prevent deformation by varying the force applied to each fine area, or to use a jig for preventing deformation, and no fine work and operation are required. Therefore, no work and no jig are required for preventing the remaining portions 22 and 23 from being deformed, so that the molding can be performed easily and with reduced work.

According to the metal molding material 20, the pins 30
Is moved while being slid with respect to the base material 25, and crystal grains are locally refined along the movement path of the pin 30, so that superplasticity is developed only in the vicinity of the movement path of the pin 30. . In the metal forming material 20, the crystal grains of the remaining portions 22, 23 excluding the fine crystal portion 21 are not refined,
Molding can be performed more easily and highly accurately in shape.

The fine crystal part 21 in which the crystal grains have been made fine has high strength at normal temperature.

According to the above-described forming method for forming such a metal forming material 20, the crystal grains of the base material 25 are locally crushed, so that they are recrystallized in The crystallized crystal grains become fine crystal grains, so that a fine crystal part 21 in which crystal grains are locally refined can be formed. This fine crystal part 21 can be made to exhibit superplasticity at a predetermined temperature and a predetermined strain rate. As compared with the case where the crystal grains of the entire base material for forming the metal forming material 21 are refined, the processing amount for refining the crystal grains can be reduced. Therefore, the processing can be performed in a short time at a low cost, with a reduced processing time.

According to the above-described forming method, the pins 30 are inserted into the base material 25 and moved while being slid, and recrystallized to refine crystal grains. When the base material 25 having a shape is prepared, the shape is not changed as in the case of rolling or extrusion and the shape is not deformed, the required shape is obtained, and the crystal grains are locally refined. The formed metal forming material 20 can be formed. Therefore, in the above-described example, although the flat plate-shaped metal forming material 20 is formed, the metal forming material 20 to be formed is not limited to such a plate-like shape, and includes, for example, cylindrical and rod-like shapes as described later. There is no restriction on the shape and material of the material. For example, a metal molding material can be formed from the above-described metals, or a part of an aluminum casting or the like can be treated so as to exhibit superplasticity to form a metal molding member. In addition, since the crystal grains can be refined only by moving the pins 30 while sliding, the metal forming material 20 can be formed by performing the refinement process easily and without using a large-scale apparatus. In addition, the crystal grains can be refined only in the vicinity of the movement path where the pin 30 has been moved, and the crystal grains can be refined only in the region where superplasticity is desired to be exhibited. It is possible to form a highly accurate metal molding material 20 in which crystal grains in the region are refined, and it is possible to easily form even a metal molding material in which a region where superplasticity is desired to be developed is small.

FIG. 7 is a perspective view for explaining a forming method for forming the forming member 40 by using the metal forming material 20. FIG. 7A shows the metal forming material 20, and FIG.
(2) shows the molded member 40. The forming member 40 is an L-shaped member, and the above-mentioned fine crystal part 21 of the metal forming material 20 is formed by superplastic working. The molding of the molding member 40 may be performed under a temperature condition at which the fine crystal part 21 develops superplasticity, for example, by using a high-pressure gas to give a strain that satisfies a strain rate condition at which superplasticity develops. In order to make it possible to apply a pressing force to the metal forming material 20 and to superplastically deform it in the fine crystal part 21,
Form a molded member. More specifically, for example, FIG.
As shown in (1), the pressing force F1 is applied to the fine crystal portion 21 at one of the thickness directions at a plurality of locations in the longitudinal direction, and the remaining portion 22 is applied to the other portion in the thickness direction at a plurality of locations in the longitudinal direction (the direction opposite to the pressing force F1). ) Is given a pressing force F2 and the remaining portion 23
By applying a pressing force F3 to the other side in the thickness direction (the same direction as the pressing force F2) at a plurality of locations in the longitudinal direction, only the fine crystal part 21 is plastically deformed, and the molded member 40 is formed.

According to such a forming method, the microcrystalline portion 21 of the metal forming material 20 which locally exhibits superplasticity is superplastically processed and the formed member 40 is formed.
23 can be easily prevented, and the molded member 40
Can be easily formed. More specifically, the remaining portions 22 and 2 which are portions that are not desired to be deformed even when a pressing force is applied to the regions spaced apart as described above to form them.
It is possible to plastically deform only the fine crystal portion 21 without devising a method for preventing the deformation of the microstructure 3, for example, without taking measures such as holding the whole with a jig. Therefore, molding is facilitated, and the molding device can be simplified.

The formed member 4 thus formed is
According to No. 0, a metal forming material 2 that locally exhibits superplasticity
Since the 0 microcrystal part 21 is formed by superplastic working, the remaining parts 22 and 23 that do not exhibit superplasticity can obtain a highly accurate formed member 40 that is not deformed.
Therefore, it can be suitably used as a component of a machine requiring high accuracy.

Metal Formed Member 2 of Another Embodiment of the Present Invention
As a method of forming 0, the base material 25 is supported on the surface plate on one side in the thickness direction, and the pins 30 are inserted from the other side in the thickness direction, and the above-described steps s0 to s6 are performed. Is also good. By providing the surface plate on the opposite side of the rotary base 29 of the rotary sliding member 28 with respect to the thickness direction of the base material 25 in this way, even if the base material is softened and fluidized, the material is fluidized. The base material is, as it were, confined in a region surrounded by the non-fluidized surrounding base material, the rotary sliding member 28 (specifically, the rotary base), and the surface plate. Therefore, leakage to the outside is prevented, and both ends in the thickness direction of the formed fine crystal part 21 are:
The metal forming material 20 can be formed so as to be flush or substantially flush with both end faces in the thickness direction of the remaining portions 22 and 23. In addition, when the surface plate is used as described above, the rotation speed N
By appropriately setting the moving speed V and the moving speed V, it is possible to prevent a problem that the base material is excessively softened due to the moving speed V becoming too slow, and the pins 30 penetrate into the surface plate and burn. it can.

As a method of forming a metal forming member 20 according to still another embodiment of the present invention, when forming a metal forming material 20 in which both end portions of the fine crystal portion 21 are exposed to the outside, a virtual line is shown in FIG. As described above, the auxiliary members 45 and 46 may be provided at both end portions of the fine crystal portion so as to face from the upstream side and the downstream side in the moving direction B of the pin 30.
Each of the auxiliary members 45 and 46 is a separate member made of the same material as the base material 25, and the end face on the side facing the end face 31 has the base material 2.
5 is provided so as to be flush with the surface on which the end face 31 faces.

When each of the auxiliary members 45 and 46 is used, in the pin insertion step of step s2, the pin 30 is once inserted into the auxiliary member 45 on the movement start position side, and moves from this state toward the base material 25. Then, it is inserted into the base material 25.
The pin 30 may be inserted into the auxiliary member 45 by moving the pin 30 in the axial direction or in a direction intersecting with the axis L1 while rotating the pin 30. Therefore, for example, by using the auxiliary member 45 including the movement start position 35,
Toward the movement start position 35, the axis direction or the axis L
It may be made to move in the direction crossing 1 and to be inserted into the auxiliary member 45. At this time, the insertion of the pin 30 can be facilitated by forming a recess such as a column in the auxiliary member 45 corresponding to the movement start position 35.

When using the auxiliary members 45 and 46,
In the above-described pin releasing step of step s4, the pin 3
No. 0 once moves into the auxiliary member 46 on the movement end position side, separates from the base material 25, and separates from the auxiliary member 46. The pin 30 may be detached from the auxiliary member 46 by moving the pin 30 in an axial direction or a direction intersecting with the axis L1 while the pin 30 is rotated. Therefore, for example, by using the auxiliary member 46 including the movement end position 36,
It is also possible to move from the movement end position 36 in the axial direction or the direction intersecting with the axis L1 to separate from the auxiliary member 46.

By using the auxiliary members 45 and 46 in this manner, even if the base material moves to the upstream side in the moving direction B due to the plastic flow accompanying the movement of the pin 30 as described above, The surplus base material on the side is collected by the auxiliary member 45, and the insufficient material on the downstream side in the moving direction B is replenished as the base material from the auxiliary member 46, so that the aforementioned steps s0 to s6 are performed. After the crystal grain refining operation is completed, the auxiliary members 45 and 46 are separated from the base material, so that the base material swells at a portion upstream of the movement direction B or has a recess at the downstream side of the movement direction B. Is prevented from being formed, and the metal molding material 20 having a shape that exactly matches the shape of the prepared base material 25 can be formed.

The base material swelled on the upstream side in the movement direction B is not collected and separated by the auxiliary member 45, but
You may make it simply cut off. Therefore, by using at least the auxiliary member 46, the prepared base material 2
The metal molding material 20 whose shape exactly matches 5 can be formed.

FIG. 8A is a perspective view showing a metal forming material 20a according to still another embodiment of the present invention.
(2) is a perspective view showing a forming member 40a formed using the metal forming material 20a. The above-mentioned metal molding material 2
It is similar to 0 and the related embodiments, and corresponding parts are denoted by the same reference numerals, and only different points will be described. The metal forming material 20a has a cylindrical shape, and has a plurality of fine crystal parts 21a extending in the axial direction at one end in the axial direction and spaced in the circumferential direction. The fine crystal portion 21a is formed by inserting the pin 30 into the cylindrical base material from the outside in the radial direction by using the rotary sliding member 28 in the same manner as in the case of the above-described rectangular flat metal forming material 20 so that the fine crystal portion 21a extends in the axial direction. It is formed by moving to.

By using this metal forming material 20a to apply a pressing force with one end in the axial direction outward in the radial direction, each fine crystal portion 21a is plastically deformed, as shown in FIG. 8 (2). As shown in the figure, the forming member 40 whose one end in the axial direction is expanded in a truncated cone shape can be easily formed. Even with such a cylindrical metal forming material 20a, a formed member can be formed such that the remaining portion 22a other than the fine crystal portion 21a is not deformed.

FIG. 9 is a side end view showing the end face of one end in the axial direction of the molded member 40a as viewed in the axial direction. As described above, by using the metal forming material 20a in which the fine crystal parts 21a are formed at intervals in the circumferential direction and forming by expanding the diameter as described above, the thickness changes at equal intervals in the circumferential direction. Specifically, it is possible to form the molded member 40a having a small thickness at each fine crystal part 21a and a large thickness at the remaining part 22a.

Further, as another embodiment of the present invention, a metal forming member in which the fine crystal parts are connected to the entire circumference is formed so that the fine crystal parts formed by one movement of the pin 30 overlap each other. It may be formed. In such a metal molding material, a molded member having a uniform thickness in the circumferential direction can be molded by enlarging and molding one end in the axial direction as described above.

FIG. 10 shows the base material 25 of the metal forming material 20a.
It is a perspective view which shows the axial direction one end part of a. In order to form the cylindrical metal forming material 20a, the cylindrical base material 25 is required.
a is prepared. In the metal forming material 20a, each fine crystal part 21a extends over the entire region in the thickness direction (radial direction), and at one end, faces outward in the axial direction, but the other end forms the metal forming material 20a. It is present in the axial middle part.

In forming such a metal forming material 20a, in the pin inserting step, the pins 30 are inserted into the base material 25a passing through the fine crystal portion 21a where the axis L1 is to be formed.
May be moved toward the inside in the radial direction, and inserted into the base material 25a. Further, at this time, a recess 5 having the same shape as the pin 30 is provided at a position where the pin 30 is to be inserted.
It is preferable to form 0. The pin 30 inserted in this way is moved along the axis to the end 3
9a to form the fine crystal part 21a,
The bulging of the base material at the other end (the end on the upstream side in the moving direction of the pin 30) of the fine crystal portion 21a can be prevented.
An annular auxiliary member 46a is provided at the other end in the axial direction of the base material 25a so that the outer peripheral surface is flush with the base material 25a, and is separated from the base material 25a so as to move to the auxiliary member 46a. In addition, it is possible to prevent a recess from being formed at one end of the fine crystal portion 21a. In addition, when such a cylindrical metal molding material is formed, by inserting a cylindrical support member therein, the effect obtained by using a surface plate when forming a flat metal molding material is obtained. The same effect as described above can be achieved.

FIG. 11 is a perspective view showing one end in the axial direction of a metal forming material 20b according to still another embodiment of the present invention. The metal forming material 21b is similar to the metal forming material 20a. The difference is that fine crystal parts 21b1, 21b2 having different lengths in the axial direction are formed alternately in the circumferential direction, and the other points are the same. Each fine crystal part 21b1,
21b2 extends in the axial direction from the end face of one end in the axial direction, and the fine crystal part 2 having a large axial length.
1b1 and a fine crystal part 21b2 having a small axial length.
Are alternately formed in the circumferential direction. Such a metal forming material 20b tends to increase in diameter at one end in the axial direction toward the end face. Therefore, it is possible to easily mold a molding member whose one end in the axial direction is expanded in a truncated cone shape.

FIG. 12A is a perspective view showing a metal forming material 20c according to still another embodiment of the present invention.
2 (2) is a perspective view showing a molding member 40c formed using the metal molding material 20c. Similar to the previously described metal forming material 20 and the related embodiments,
Corresponding parts have the same reference characters allotted, and only different points will be described. The metal forming material 20c has a cylindrical shape, and has fine crystal parts 21c that extend spirally at intervals in the axial middle part. This fine crystal part 21c
Is formed by inserting the pin 30 into the cylindrical base material from the outside in the radial direction and moving it spirally using the rotary sliding member 28 in the same manner as described above.

By using the metal forming material 20c to apply a pressing force in the opposite direction between the both ends in the axial direction and the intermediate portion in the axial direction, the fine crystal portion 21c is plastically deformed, and as shown in FIG. As shown in (5), the cylindrical forming member 40c bent at the middle portion in the axial direction can be easily formed. Even with such a metal molding material 20c,
The molded member can be formed such that the remaining portion 22c other than the fine crystal portion 21c is not deformed.

FIG. 13 shows the base material 25 of the metal forming material 20c.
It is sectional drawing which shows a part of c. When both ends of the fine crystal part 21c are not exposed to the outside like the metal molding material 20c, in forming the metal molding material 20c,
In the pin insertion step, by forming a recess in the base material 25c as described with reference to FIG. 10, it is possible to prevent the base material from expanding as described above. In this case, the wedge-shaped auxiliary member 46c has a pointed end located at the end of the fine crystal portion 21c on the downstream side in the moving direction of the pin 30, and the diameter of the wedge-shaped auxiliary member 46c increases as the distance from the pointed end increases. One of the end surfaces 51, 52 is provided in contact with the base material surface, and the pin 30 is inserted from the state 53 into the base material 25c.
The end surface 31 of the rotating base 29 moves along the other 52 of the end surfaces 51, 52 of the auxiliary member 46c, and the movement end position 39c may be moved to a state 54 in which the end position 39c is present in the auxiliary member 46c. . As a result, the material can be replenished from the auxiliary member 46c so that no recess is formed in the metal molding material 20c.

FIG. 14A is a perspective view showing a metal forming material 20d according to still another embodiment of the present invention.
4 (2) is a perspective view showing a molded member 40d formed using the metal molding material 20d. Similar to the previously described metal forming material 20 and the related embodiments,
Corresponding parts have the same reference characters allotted, and only different points will be described. The metal forming material 20d is flat and has a spiral fine crystal part 21d formed in a region near one corner. The fine crystal part 21d is formed by inserting the pin 30 into the base material from the thickness direction and moving it in a spiral shape using the rotary sliding member 28 as described above.

Using the metal forming material 20d, a region where the fine crystal part 21d is formed is pressed from one side in the thickness direction, and a peripheral region is pressed from the other side in the thickness direction to plastically deform the fine crystal part 21d. FIG.
As shown in (2), it is possible to easily mold the molding member 40d having a shape in which a part of the region protrudes from the remaining flat region. Even with such a rectangular metal forming material 20d, a formed member can be formed such that the remaining portion 22d other than the fine crystal portion 21d is not deformed.

FIG. 15A is a perspective view showing a metal forming material 20e according to still another embodiment of the present invention.
5 (2) is a perspective view showing a forming member 40e formed using the metal forming material 20e. Similar to the previously described metal forming material 20 and the related embodiments,
Corresponding parts have the same reference characters allotted, and only different points will be described. The metal forming material 20e is a material having an L-shaped cross section perpendicular to the longitudinal direction, and has a fine crystal part 21e formed over the entire central portion at the longitudinal center. The fine crystal part 21e is formed by inserting the pin 30 into the base material from the thickness direction using the rotary sliding member 28 in the same manner as described above, and moving the pin 30 to the entire central part so that the movement path overlaps. Is done.

By using the metal forming material 20e, the central portion where the fine crystal portion 21e is formed and both ends in the longitudinal direction are pressed from opposite sides, and the fine crystal portion 21e is plastically deformed. As shown in (2), the forming member 40e having an L-shaped cross section bent at the center can be easily formed. Such an L-shaped metal forming material 20e
Even in this case, the molded member can be formed such that the remaining portion 22e excluding the fine crystal portion 21e is not deformed.

As a method of forming a metal forming material according to still another embodiment of the present invention, a base material for forming a metal which undergoes a phase transformation at a transformation point lower than the melting point, for example, a metal forming material made of carbon steel, is locally applied. The heat treatment may be repeated in a temperature change cycle that passes through the transformation point to refine the crystal grains of the heat treated fine crystal part. Specifically, for example, when forming the metal molding material 20 of FIG.
The above-mentioned heat treatment is performed on the portion of the base material 25 where the fine crystal part is to be formed using the heating means, and the portion corresponding to the remaining portion is cooled using the cooling means so that the heat treatment by the heating means is not performed. Thus, the metal forming material 20 is formed. By performing a partial heat treatment in this manner, the heat-treated portion undergoes a phase transformation, and the original crystal grains are crushed.
Thermal recrystallization takes place in this crushed crystal part. By performing a heat treatment so that the recrystallized crystal grains do not grow large, the crystal grains can be refined.

According to the method for forming a metal forming material to be heat-treated in this manner, the base material 25 is re-crystallized by repeating the heat treatment in a temperature change cycle that locally passes through the transformation point. When a base material having the same shape as the metal forming material 20 to be formed is prepared, the shape is required, and the crystal grains are locally refined without deforming the shape. The metal molding material 20 can be formed. In addition to the flat plate shape, FIGS.
There is no limitation on the shape of the metal forming material to be formed, including the shapes shown in FIGS. 12, 14 and 15, and also the shapes such as, for example, cylindrical shapes and rod shapes. Also, the crystal grains can be refined only by heat treatment,
Easy to form. In addition, the crystal grains can be refined only in the vicinity of the heat-treated area, and the crystal grains can be refined only in the area where superplasticity is to be exhibited. It is possible to form a highly accurate metal forming material. Further, the heat treatment can be performed over a wide range, and it can be easily formed even if the metal forming material 20 has a large fine crystal part 21 in which superplasticity is to be developed. Such an effect is achieved regardless of the shape.

The metal forming material 20 formed by such a heat treatment also exhibits superplasticity only in the vicinity of the heat treatment region. In the metal forming material 20, the crystal grains of the remaining portions 22, 23 excluding the fine crystal portion 21 are not refined,
Molding can be performed more easily and highly accurately in shape.

As another embodiment of the present invention, a pin 30
In the method of moving while rotating, the base material 25 may be heated so that the base material 25 can easily reach the softening point. Thereby, the moving speed V of the pin 30 can be increased, and the forming time can be shortened. At this time, heating is performed so that the portion where crystal grains are not desired to be refined is not heated to a temperature higher than the softening point.

As still another embodiment of the present invention, a pin 3 rotated to plastically flow a base material is provided.
Instead of 0, the sliding piece to be reciprocated by the piston may be moved in a direction intersecting the direction of the reciprocating movement. With such a method, a metal forming material can be formed in the same manner as when the pin 30 is rotated.

[0076]

According to the first aspect of the present invention, the fine crystal part in which the crystal grains are refined expresses superplasticity at a predetermined temperature and a predetermined strain rate, and the remaining part does not express superplasticity. In performing the plastic working of the metal forming material, it is not necessary to perform fine operations and operations such as changing a force to be applied to each fine region or using a jig for that in order to prevent the remaining portion from being deformed. . Accordingly, the molding can be performed easily and with less labor without requiring any labor and jig for preventing the remaining portion from being deformed.

According to the present invention, the sliding piece is moved while sliding with respect to the base material, and the crystal grains are locally refined along the moving path of the sliding piece. Therefore, superplasticity appears only in the vicinity of the moving path of the sliding piece. In the metal forming material, the crystal grains in the remaining portion other than the fine crystal portion are not refined, so that the forming can be performed more easily and the shape can be formed with high precision.

According to the third aspect of the present invention, according to the present invention, the heat treatment is repeated in a temperature change cycle in which the base material locally passes the transformation point, and the crystal grains are locally refined. Therefore, superplasticity develops only in the vicinity of the heat treatment region.
In the metal forming material, the crystal grains in the remaining portion other than the fine crystal portion are not refined, so that the forming can be performed more easily and the shape can be formed with high precision.

According to the present invention, when the crystal grains of the base material are locally crushed, they are recrystallized in the crushed crystal parts, and the recrystallized crystal grains become fine crystal grains. Thereby, crystal grains are locally refined, and superfine plasticity can be developed in the fine crystal portion at a predetermined temperature and a predetermined strain rate. Compared with the case where the crystal grains of the entire base material for forming the metal forming material are refined, the processing amount for refining the crystal grains can be reduced. Therefore, the processing can be performed in a short time at a low cost, with a reduced processing time.

According to the fifth aspect of the present invention, the sliding piece is inserted into the base material, moved while sliding, and recrystallized to refine the crystal grains. When a base material having the same shape is prepared, a metal forming material having a required shape and locally refined crystal grains can be formed without deforming the shape. Therefore, the shape of the metal forming material to be formed is not limited to a flat plate shape, for example, including a cylindrical shape and a rod shape. In addition, since the crystal grains can be refined only by moving the sliding piece while sliding, the metal forming material can be formed by the refinement treatment easily and without using a large-scale apparatus. In addition, the crystal grains can be refined only in the vicinity of the movement path where the sliding piece has been moved, and the crystal grains can be refined only in the region where superplasticity is to be developed. A high-precision metal forming material in which crystal grains in a high region are refined can be formed, and even a metal forming material in which a region where superplasticity is desired to be developed is small can be easily formed.

The conventional superplastic moldable material has a very narrow range, such as one containing an alloy component that suppresses recrystallization growth. However, according to the present method, a wide range of material can be finely divided. It can be crystallized and made superplastic.

According to the sixth aspect of the present invention, the base material is
Heat treatment is repeated and recrystallized in a temperature change cycle that locally passes through the transformation point to refine the crystal grains in the fine crystal part, so if a base material having the same shape as the metal forming material to be formed is prepared, It is possible to form a metal forming material having a required shape and locally refined crystal grains without deforming the shape. Therefore, the shape of the metal forming material to be formed is not limited to a flat plate shape, for example, including a cylindrical shape and a rod shape. Further, since the crystal grains can be refined only by performing the heat treatment, the formation is easy. In addition, the crystal grains can be refined only in the vicinity of the heat-treated area, and the crystal grains can be refined only in the area where superplasticity is to be exhibited. It is possible to form a highly accurate metal forming material. In addition, the heat treatment can be performed over a wide range, and a metal forming material having a wide fine crystal part to exhibit superplasticity can be easily formed.

According to the present invention, since the fine crystal portion of the metal forming material that locally exhibits superplasticity is formed by superplastic working, the remaining portion that does not exhibit superplasticity is: A highly accurate molded member that is not deformed can be obtained.

According to the present invention, the fine crystal part of the metal forming material which locally exhibits superplasticity is subjected to superplastic processing to form a formed member, so that the deformation of the remaining part is easily prevented. Therefore, the molded member can be easily molded.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a metal forming material 20 according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II in FIG.

FIG. 3 is an enlarged cross-sectional view showing a fine crystal part 21 of FIG. 2;

FIG. 4 is a perspective view for explaining a method of forming the metal forming material 20.

FIG. 5 is a front view showing the rotary sliding member 28;

FIG. 6 is a flowchart showing a procedure for forming a metal forming material 20;

FIG. 7 is a perspective view showing a metal forming material 20 and a forming member 40.

FIG. 8 shows a metal forming material 20a according to another embodiment of the present invention.
FIG. 4 is a perspective view showing a molding member 40a.

FIG. 9 is a side end view showing an end surface of one end in the axial direction of the metal molding material 20a.

FIG. 10 is a perspective view showing a base material 25a.

FIG. 11 is a perspective view showing a metal forming material 20b according to still another embodiment of the present invention.

FIG. 12 is a perspective view showing a metal forming material 20c and a forming member 40c according to still another embodiment of the present invention.

FIG. 13 is a sectional view showing a base material 25c.

FIG. 14 is a perspective view showing a metal forming material 20d and a forming member 40d according to still another embodiment of the present invention.

FIG. 15 is a perspective view showing a metal forming material 20e and a forming member 40e according to still another embodiment of the present invention.

FIG. 16 is a perspective view showing a molding member 1 according to a conventional technique.

FIG. 17 is a perspective view showing another molding member 7 of the related art.

FIG. 18 is a perspective view showing a molding member 10 according to the related art.

[Explanation of symbols]

 20, 20a to 20e Metal forming material 21, 21a to 21e Fine crystal part 22, 22a to 22e, 23 Residual part 25 Base material 26 Crushed crystal part 28 Rotating sliding member 29 Rotating base 30 Pin 31 End face 40 Molded part 45, 46, 46a, 46c auxiliary members

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme Court II (Reference) C22K 3:00 C22K 3:00 (72) Inventor Yoshikazu Ikemoto 3-1-1 Higashikawasakicho, Chuo-ku, Kobe-shi, Hyogo Prefecture Kawasaki Heavy Industries, Ltd.Kobe Factory

Claims (8)

[Claims] 1. A metal forming material characterized in that crystal grains are locally refined, and a fine crystal part in which the crystal grains are refined expresses superplasticity at a predetermined temperature and a predetermined strain rate. 2. A sliding piece is inserted into a base material for forming a metal forming material, and the sliding piece is moved while being slid with respect to the base material, and is moved along a moving path of the sliding piece. 2. The crystal grain is locally refined by the method.
Metal forming material as described. 3. The heat treatment is repeated in a temperature change cycle in which a base material for forming a metal forming material made of a metal that undergoes phase transformation at a transformation point lower than the melting point locally passes through the transformation point. 2. The metal forming material according to claim 1, wherein the crystal grains in the fine crystal part are refined. 4. A method for forming a metal forming material, comprising locally crushing crystal grains of a base material for forming the metal forming material, and recrystallizing the crystal grains in the crushed crystal portion. . 5. A sliding piece is inserted into a base material for forming a metal molding material, and the sliding piece is moved while sliding with respect to the base material. The method for forming a metal forming material according to claim 4, wherein recrystallization is performed locally. 6. A base material for forming a metal forming material made of a metal which undergoes a phase transformation at a transformation point lower than a melting point is subjected to a heat treatment repeatedly in a temperature change cycle in which the base material locally passes through the transformation point. The method for forming a metal forming material according to claim 4, wherein recrystallization is performed at the formed fine crystal part. 7. A formed member, wherein the fine crystal part of the metal forming material according to claim 1 is formed by superplastic working. 8. A forming method, comprising: using the metal forming material according to any one of claims 1 to 3, superplastically processing the fine crystal part to form a formed member.