TWI522483B - Copper alloy, thin plate of copper alloy and method for producing copper alloy - Google Patents

Description

Copper alloy, copper alloy sheet and copper alloy manufacturing method

The present invention relates to a mechanical component, an electrical component, a switch component, a bus bar, a connector, or the like, or an industrial device, such as a semiconductor component such as a home appliance or a lead frame for a semiconductor device, or a printed wiring board. Copper alloy strips are suitable copper alloys, copper alloy sheets, and copper alloys.

This patent application claims priority based on Japanese Patent Application No. 2013-167045, filed on Jan. 9, 2013, the entire entire entire entire entire entire entire entire entire entire entire entire And refer to this content for reference.

Copper alloys which are various uses as described above are conventionally used as a Cu-Fe-P-based copper alloy containing Fe and P. As a Cu-Fe-P-based copper alloy, a copper alloy (CDA19400 alloy) containing Fe: 2.1% by mass or more and 2.7% by mass or less, P: 0.015% by mass or more and 0.15% by mass or less, and Zn: 0.05 mass may be exemplified. % or more and 0.20% by mass or less. Further, the CDA 19400 alloy is an international standard alloy specified by the CDA (Copper Development Association).

Here, the above-mentioned CDA19400 alloy is widely used in various types of precipitation-strengthening alloys in which an intermetallic compound such as Fe or Fe-P is precipitated in a copper matrix phase, and is excellent in strength, electrical conductivity, and thermal conductivity. use.

In recent years, with the expansion of the use of Cu-Fe-P-based copper alloys, or the weight reduction, thinning, and miniaturization of electrical and electronic equipment, CDA19400 alloys are required to have higher strength, conductivity, and excellent performance. Bending workability.

Further, the lead frame, the connector, and the like are manufactured by etching or punching a copper alloy sheet. Here, when the copper alloy sheet composed of the CDA 19400 alloy or the like is subjected to punching, the mold has a sharp wear and the use of the mold must be replaced in a short period of time.

For this reason, for example, in the patent documents 1 and 2, it is proposed to add C to the Cu-Fe-P alloy in order to suppress cracks in the hot rolling step and improve the properties such as the wear resistance of the blanking die. Moreover, in order to improve the characteristics of the strength of the Cu-Fe-P alloy, etc., it is proposed to add Mg or the like.

[Previous Technical Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 11-323464

[Patent Document 2] Japanese Patent Laid-Open No. Hei 11-350055

However, a copper alloy composed of a Cu-Fe-P alloy has a large number of surface defects when rolling a cast ingot to produce a copper alloy sheet. When the above surface defects are present, there is a problem that the manufacturing cost of the copper alloy sheet is greatly increased because the manufacturing yield is drastically lowered.

Further, when the copper alloy sheet composed of the Cu-Fe-P-based alloy is subjected to press working, etching, or silver plating, a non-smooth shape defect of the coarse iron alloy particles may occur.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a copper alloy, a copper alloy sheet, and a method for producing a copper alloy, which are capable of suppressing generation of surface defects and shape defects in a Cu-Fe-P alloy. .

In order to solve this problem, the inventors of the present invention have conducted intensive studies and found that the surface defects and shape defects of the Cu-Fe-P alloy produced in the CDA19400 alloy or the like are caused by the exposure of the iron alloy particles containing Fe and C to the copper alloy. Formed on the surface of the sheet.

It is also known that when a certain amount or more of C is present in the copper alloy melt, "the liquid phase containing Fe as a main component and containing C" and the liquid phase containing "Cu as a main component" are separated by liquid phase, and the ingot is ingot. Large Fe-C crystals will be formed inside. The following insight is obtained: the coarse Fe-C junction formed in the ingot The crystal is a cause, and iron alloy particles exposed on the surface of the copper alloy sheet are formed.

The present invention is based on the above-described findings, and the copper alloy according to the first aspect of the present invention contains Fe: 1.5% by mass or more and 2.7% by mass or less, and P: 0.008% by mass or more and 0.15% by mass or less, and Zn: 0.01% by mass or more and 0.5% by mass or less, and the residual portion is Cu and unavoidable impurities, and the content of C contained as the unavoidable impurities is less than 3 ppm by mass.

In the copper alloy of this constitution, the content of C which is unavoidable is controlled to be less than 3 ppm by mass. As described above, since the C system has an element which promotes the liquid phase separation of the "liquid phase containing Fe as a main component and containing C" and the liquid phase containing "Cu as a main component", the more the content of C is, the more the content of C is. The easier it is to form coarse Fe-C crystals in the ingot. According to this, by controlling the content of C as described above, generation of coarse Fe-C crystals can be suppressed, and surface defects of the iron alloy particles can be greatly reduced. Further, it is possible to suppress the shape defect of the product due to the coarse Fe-C crystal.

Here, the copper alloy of the present invention may further contain any one or both of Ni: 0.003 mass% or more and 0.5 mass% or less, and Sn: 0.003 mass% or more and 0.5 mass% or less.

At this time, Ni or Sn can be attempted to increase the strength of the Cu-Fe-P-based copper alloy by being dissolved in the mother phase of Cu.

Further, in the copper alloy of the present invention, Mg, Ca, and Sr may be further contained in a range of 0.0007 mass% or more and 0.5 mass% or less. At least one or two or more of Ba, a rare earth element, Zr, Si, Al, Be, Ti, and Co.

At this time, by using elements such as Mg, Ca, Sr, Ba, rare earth elements, Zr, Si, Al, Be, Ti, Co, etc., the strength of the Cu-Fe-P alloy can be improved and the die-resistant mold can be tried. Increase in wear and tear.

Further, in the copper alloy of the present invention, the content of Mn contained in the unavoidable impurities is preferably 20 ppm by mass or less, and the content of Ta is 1 ppm by mass or less.

When the copper alloy melt is liquid phase separated as described above, the element such as Mn or Ta is contained in the "liquid phase containing Fe as a main component and contains C", and tends to promote liquid phase separation. Therefore, when Mn and Ta containing too many unavoidable impurities are excessive, there is a possibility that coarse Fe-C crystals are easily formed in the ingot. Therefore, by setting the content of Mn to 20 ppm by mass or less and the content of Ta to 1 ppm by mass or less, it is possible to reliably suppress the generation of coarse Fe-C crystals.

A copper alloy sheet according to a second aspect of the present invention is a copper alloy sheet composed of the copper alloy, wherein surface defects having a length of 200 μm or more formed by exposing the iron alloy particles containing Fe and C to the surface are 5 /m ² or less. More preferably, the surface defects having a length of 200 μm or more are set to 2/m ² or less, and preferably set to less than 1 / m ² .

Further, in the copper alloy sheet of the present invention, the thickness of the sheet is set to 0.5 mm or less.

According to the copper alloy sheet having such a configuration, since the content of C which is unavoidable impurities is a copper alloy which is suppressed to be low, generation of iron alloy particles containing Fe and C can be suppressed, and the iron alloy particles can be suppressed from being caused. The occurrence of surface defects. Further, it is possible to suppress the shape defect of the product due to the coarse Fe-C crystal. Further, by setting the surface defects having a length of 200 μm or more to 5/m ² or less, it is possible to remarkably reduce the defect rate of the product which is caused by press working, etching, or silver plating. In particular, when the thickness of the copper alloy sheet is 0.5 mm or less, when there is a surface defect of 200 μm or more, the thickness direction is also defective, and for example, pressing, etching, or the like is performed to impart a fine shape. When processing, it will become a cause of failure. From the above viewpoints, when the thickness of the copper alloy sheet is 0.2 mm or less, the effects of the present invention can be further exerted. When the manufacturing cost of the copper alloy sheet and the obtained effect are considered, it is preferable that the lower limit of the thickness of the thin plate is 0.05 mm, but it is not limited thereto.

A method for producing a copper alloy according to a third aspect of the present invention is the method for producing a copper alloy, comprising the steps of: melting a raw material to form a melting step of a copper alloy melt; and maintaining the copper alloy melt in the molten metal The high temperature holding step of 1300 ° C or higher and the molten copper alloy which is maintained at 1300 ° C or higher are supplied to the mold to obtain a casting step of the ingot.

According to the method for producing a copper alloy having such a configuration, a casting step of obtaining an ingot by providing a high-temperature holding step of holding a copper alloy melt at 1300 ° C or higher and supplying a molten copper alloy held at 1300 ° C or higher to a mold is provided. Therefore, in the copper alloy melt, liquid phase separation of "liquid phase containing Fe as a main component and containing C" and "liquid phase containing Cu as a main component" can be suppressed, and coarse Fe-C crystals can be suppressed. The generation. According to this, The surface defects caused by the iron alloy particles can be reduced. Further, it is possible to suppress the shape defect of the product due to the coarse Fe-C crystal.

According to the present invention, a copper alloy, a copper alloy sheet, and a copper alloy can be produced, which are capable of suppressing generation of surface defects and shape defects in a Cu-Fe-P alloy.

S01‧‧‧ melting step

S02‧‧‧High temperature maintenance steps

S03‧‧‧ casting steps

RD‧‧‧Rolling direction

L‧‧‧ Length of surface defects

[Fig. 1] An optical microscopic observation photograph of a surface defect of a copper alloy sheet.

Fig. 2 is a flow chart showing a method of producing a copper alloy according to an embodiment of the present invention.

[Best Practice for Carrying Out the Invention]

Hereinafter, a copper alloy according to a first embodiment of the present invention will be described.

The copper alloy according to the first embodiment of the present invention contains Fe: 1.5% by mass or more and 2.7% by mass or less, P: 0.008% by mass or more and 0.15% by mass or less, and Zn: 0.01% by mass or more and 0.5% by mass or less, and the residual portion The portion is Cu and an unavoidable impurity, and the content of C contained as an unavoidable impurity is less than 3 ppm by mass.

Hereinafter, the reason why the content of these elements is set to the above range will be described.

(Fe)

Fe is a solid solution in the mother phase of Cu, and a precipitate containing P (Fe-P compound) is formed at the same time. By dispersing the Fe-P compound in the mother phase of Cu, the electrical conductivity is not lowered, and the strength and hardness are improved.

Here, when the content of Fe is less than 1.5% by mass, the effect of strength improvement or the like is insufficient. On the other hand, when the content of Fe exceeds 2.7% by mass, a large crystal is formed to impair the cleanliness of the surface. Further, there is a problem that the conductivity and the workability are lowered.

Therefore, in the present embodiment, the content of Fe is set to be 1.5% by mass or more and 2.7% by mass or less. In order to achieve the above-described effects, the content of Fe is preferably in the range of 1.8% by mass or more and 2.6% by mass or less.

(P)

P is an element having a deoxidation effect. Further, as described above, an Fe-P compound is formed simultaneously with Fe. By dispersing the Fe-P compound in the mother phase of Cu, the electrical conductivity is not lowered, and the strength and hardness are improved.

Here, when the content of P is less than 0.008% by mass, the effect of strength improvement or the like is insufficient. On the other hand, when the content of P exceeds 0.15% by mass, the electrical conductivity and workability are lowered.

Therefore, in the present embodiment, the content of P is set to 0.008. The amount % or more is 0.15 mass% or less. In order to achieve the above-described effects, the content of P is preferably in the range of 0.01% by mass or more and 0.05% by mass or less.

(Zn)

Zn is an element which is solid-solubilized in the mother phase of Cu and has an effect of improving the heat-resistant peelability of the solder.

Here, when the content of Zn is less than 0.01% by mass, the effect of improving the solder heat-resistant peeling property cannot be sufficiently obtained. On the other hand, even if the content of Zn exceeds 0.5% by mass, the effect is saturated.

Therefore, in the present embodiment, the content of Zn is set to be 0.01% by mass or more and 0.5% by mass or less. In order to achieve the above-described effects, the content of Zn is preferably in the range of 0.05% by mass or more and 0.35% by mass or less.

(C)

C is contained in the above copper alloy as an unavoidable impurity. Here, when the content of C is large, the surface defects of the copper alloy sheet are greatly increased. The result of observing one of the surface defects by an optical microscope is shown in Fig. 1.

As a result of analysis by EPMA (Electron Probe Micro Analyzer), the surface defects observed in the present embodiment were caused by iron alloy particles having Fe and C.

In general, when melting the above copper alloy, the Fe element The element is present in the state of melting in the "liquid phase containing Cu as the main component". However, when C is present in a certain amount or more, the copper alloy melt is separated into "liquid phase containing Cu as a main component" and "liquid phase containing Fe as a main component and containing C", and as a result, coarse Fe- The C crystal will be present in the ingot. Thereafter, by rolling the ingot, the iron alloy particles resulting from the coarse Fe-C crystals are exposed on the surface of the copper alloy sheet, and it is considered that the above surface defects are generated. Further, when the iron alloy particles are subjected to press working, etching, or silver plating, a shape defect occurs.

Therefore, by reducing the C element, surface defects and shape defects caused by the iron alloy particles can be suppressed. Here, in the present embodiment, the content of the restriction C is less than 3 ppm by mass. In order to reliably achieve the above-mentioned suppression of surface defects and shape defects, it is preferred to set the content of C to less than 2 ppm by mass.

Further, as an unavoidable impurity other than C, for example, Ni, Sn, Mg, Ca, Sr, Ba, rare earth elements, Zr, Si, Al, Be, Ti, H, Li, B, N, O, F, Na, S, Cl, K, V, Cr, Mn, Co, Ga, Ge, As, Se, Br, Rb, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sb, Te, I, Cs, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, and the like. Such unavoidable impurities are preferably 0.3% by mass or less based on the total amount. When the manufacturing cost of the copper alloy and the effect obtained are considered, the lower limit of the total amount of the unavoidable impurities is preferably 0.1% by mass, but is not limited thereto.

Next, a method for producing a copper alloy according to the embodiment An example will be described with reference to the flowchart shown in FIG. 2.

<melting step S01>

The copper raw material, pure iron, Zn or Cu-Zn master alloy, P or Cu-P master alloy is melted to form a copper alloy melt. In addition, the copper raw material is so-called 4NCu having a purity of 99.99% by mass or more, and the pure iron is so-called 3NFe having a purity of 99.9% by mass or more, or 49.7% by mass or more, and the atmosphere is preferably Ar. The temperature in the melting, for example, 1100 to 1300 °C.

<High temperature maintaining step S02>

Next, the obtained copper alloy melt was heated to 1300 ° C or higher and held. By maintaining the copper alloy melt at a high temperature, liquid phase separation in the copper alloy melt can be suppressed. In the high temperature holding step S02, the temperature is preferably 1300 ° C or more and 1500 ° C or less, and the holding time is set to be in the range of 1 min or more and 24 h or less.

<Casting step S03>

Further, a molten alloy of 1300 ° C or higher is poured into a mold from a state of being maintained at a high temperature to produce an ingot. In this manner, the ingot of the copper alloy of the present embodiment can be produced.

Here, the cooling rate at the time of casting is preferably a high speed. For example, the cooling rate from 1300 ° C to 900 ° C is preferably 5 ° C / s or more, and more preferably 10 ° C / s or more. When considering the manufacturing cost of the copper alloy and the effect obtained, the above upper limit of the cooling rate is preferably 200 ° C / s, but is not limited herein.

After the hot rolling is performed on the obtained ingot, a copper alloy sheet having a specified thickness can be produced by appropriately repeating cold rolling and heat treatment. The hot rolling pass is carried out under the conditions of 750 ° C to 1000 ° C in a reducing atmosphere. The reduction ratio of the cold rolling is 40 to 95%, the heat treatment is performed at 400 to 700 ° C, and the final annealing is performed at 200 to 350 ° C after the final rolling.

In the copper alloy sheet, surface defects having a length of 200 μm or more formed by exposing the iron alloy particles containing Fe and C to the surface are 5/m ² or less. The surface defect of 200 μm or more is preferably 2/m ² or less. Further, it is preferably 1/m ² or less.

According to the present embodiment, the amount of C contained in the unavoidable impurities is less than 3 ppm by mass, so that generation of coarse Fe-C crystals in the ingot can be suppressed. According to this, formation of the iron alloy particles due to the coarse Fe-C crystals can be suppressed, and the occurrence of surface defects can be greatly reduced. Moreover, the shape defect of a product can be suppressed.

Further, in the production method of the present embodiment, the high temperature holding step S02 for maintaining the copper alloy melt at a high temperature of 1300 ° C or higher and the copper alloy melt held at 1300 ° C or higher are supplied to the mold to produce an ingot. Since the casting step S03 is carried out, the formation of coarse Fe-C crystals can be suppressed.

Hereinafter, a copper alloy according to a second embodiment of the present invention will be described.

The copper alloy according to the second embodiment of the present invention contains Fe: 1.5% by mass or more and 2.7% by mass or less, and P: 0.008% by mass or more and 0.15 mass%. 5% by mass or less, Zn: 0.01% by mass or more and 0.5% by mass or less, and Ni: 0.003 mass% or more and 0.5 mass% or less, and Sn: 0.003 mass% or more and 0.5 mass% or less, or both, and further, 0.0007 mass At least one or two or more of Mg, Ca, Sr, Ba, a rare earth element, Zr, Si, Al, Be, Ti, and Co are contained in a range of 0.5% or more and 0.5% by mass or less, and the residual portion is Cu and The unavoidable impurity contains C in an amount of less than 3 ppm by mass as the unavoidable impurities.

Hereinafter, the reason why the content of these elements is set to the above range will be described. The same elements as those of the first embodiment will be omitted.

(Ni)

Ni is a solid solution in the mother phase of Cu and has an effect of improving the strength and resistance to bending fatigue of the lead (resistance to repeated bending fatigue).

Here, when the content of Ni is less than 0.003 mass%, the above effects cannot be sufficiently obtained. On the other hand, when the content of Ni exceeds 0.5% by mass, the electrical conductivity is remarkably lowered.

Therefore, in the present embodiment, the content of Ni is set to be 0.003% by mass or more and 0.5% by mass or less. In order to achieve the above-described effects, the content of Ni is preferably in the range of 0.008% by mass or more and 0.2% by mass or less.

(Sn)

Sn is solid-dissolved in the mother phase of Cu and has strength and weldability. The role of the rise.

Here, when the content of Sn is less than 0.003 mass%, the above effects cannot be satisfactorily achieved. On the other hand, when the content of Sn exceeds 0.5% by mass, the electrical conductivity is remarkably lowered.

Therefore, in the present embodiment, the content of Sn is set to be 0.003% by mass or more and 0.5% by mass or less. In order to achieve the above-described effects, the content of Sn is preferably in the range of 0.008% by mass or more and 0.2% by mass or less.

(Mg, Ca, Sr, Ba, rare earth elements, Zr, Si, Al, Be, Ti, Co)

Mg, Ca, Sr, Ba, rare earth elements, Zr, Si, Al, Be, Ti, Co are solid-dissolved in the mother phase of copper, or exist as precipitates or crystals, and have Cu-Fe The effect of the strength enhancement of the -P alloy also has the effect of making the die-resistant mold wear-resistant.

Here, when the content of Mg, Ca, Sr, Ba, a rare earth element, Zr, Si, Al, Be, Ti, and Co is less than 0.0007 mass%, the above effects cannot be sufficiently obtained. On the other hand, when the content of Mg, Ca, Sr, Ba, rare earth elements, Zr, Si, Al, Be, Ti, and Co exceeds 0.5% by mass, the electrical conductivity is lowered and a large oxide or a large oxide is easily formed. Precipitates or crystals, which in turn impair the cleanliness of the surface.

Therefore, the copper alloy of the present embodiment has a content of Mg, Ca, Sr, Ba, a rare earth element, Zr, Si, Al, Be, Ti, and Co of 0.0007 mass% or more and 0.5 mass% or less. Still, to be sure In order to achieve the above-described effects, the content of Mg, Ca, Sr, Ba, rare earth elements, Zr, Si, Al, Be, Ti, and Co is preferably in the range of 0.005 mass% or more and 0.15 mass% or less.

Here, the rare earth element means Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.

Further, as an inevitable impurity other than C, for example, H, Li, B, N, O, F, Na, S, Cl, K, V, Cr, Mn, Ga, Ge, As, Se, Br, Rb, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sb, Te, I, Cs, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi et al. Such unavoidable impurities are preferably 0.3% by mass or less based on the total amount. When the manufacturing cost of the copper alloy and the effect obtained are considered, the lower limit of the total amount of the unavoidable impurities is preferably 0.1% by mass, but is not limited thereto.

The copper alloy according to the second embodiment is produced by the melting step S01, the high temperature holding step S02 of the melt, and the casting step S03 which are the same as those of the first embodiment. In the melting step S01, for the addition of Ni, Sn, Mg, Ca, Sr, Ba, a rare earth element, Zr, Si, Al, Be, Ti, and Co, a single element of a metal element or a mother alloy containing the above element is used.

According to the present embodiment configured as described above, since Ni and Sn are contained, it is possible to attempt to increase the strength by solid solution hardening.

In addition, at least one or two or more of Mg, Ca, Sr, Ba, a rare earth element, Zr, Si, Al, Be, Ti, and Co are contained in a range of 0.0007 mass% or more and 0.5 mass% or less. Can try Cu-Fe-P The alloy is further strengthened in strength, and at the same time attempts to improve the wear resistance of the punching die.

Further, since the content of C is less than 3 ppm by mass, the formation of iron alloy particles containing Fe and C can be suppressed, and the occurrence of surface defects can be greatly reduced. Moreover, the shape defect of a product can be suppressed.

Hereinafter, a copper alloy according to a third embodiment of the present invention will be described.

The copper alloy according to the third embodiment of the present invention contains Fe: 1.5% by mass or more and 2.7% by mass or less, P: 0.008% by mass or more and 0.15% by mass or less, and Zn: 0.01% by mass or more and 0.5% by mass or less, and the residual portion The content of C contained in the unavoidable impurities is less than 3 ppm by mass, the content of Mn is 20 ppm by mass or less, and the content of Ta is 1 ppm by mass or less.

Hereinafter, the reason why the content of these elements is set to the above range will be described. The same elements as those of the first embodiment will be omitted.

(Mn, Ta)

Mn and Ta are contained in the copper alloy as an unavoidable impurity.

In general, when the copper alloy is melt-cast, the Fe element is present in a molten phase in the "liquid phase containing Cu as a main component". However, when C is present in a certain amount or more, the copper alloy melt is separated into "liquid phase containing Cu as a main component" and "liquid phase containing Fe as a main component and containing C". in When the copper alloy melt is separated in the liquid phase as described above, Mn and Ta are contained in the "liquid phase containing Fe as a main component and containing C", and are elements which promote the liquid phase separation.

Therefore, by reducing the content of Mn and Ta while reducing the C element, the liquid phase separation of the copper alloy melt can be suppressed, the formation of coarse Fe-C crystals can be suppressed, and the surface defects and shapes caused by the iron alloy particles can be suppressed. bad. Therefore, in the copper alloy of the present embodiment, the content of C is limited to less than 3 ppm by mass, the content of Mn is limited to 20 ppm by mass or less, and the content of Ta is limited to 1 ppm by mass or less. In order to reliably achieve the above-mentioned suppression of surface defects and shape defects, it is preferable to set the content of C to less than 2 ppm by mass, to set the content of Mn to less than 15 ppm by mass, and to set the content of Ta to be less than Full 0.7 mass ppm.

Further, as an unavoidable impurity other than C, Mn, and Ta, for example, Ni, Sn, Mg, Ca, Sr, Ba, a rare earth element, Zr, Si, Al, Be, Ti, H, Li, B, N, O, F, Na, S, Cl, K, V, Cr, Co, Ga, Ge, As, Se, Br, Rb, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sb, Te, I, Cs, Hf, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, and the like. Such unavoidable impurities are preferably 0.3% by mass or less based on the total amount. When the manufacturing cost of the copper alloy and the effect obtained are considered, the lower limit of the total amount of the unavoidable impurities is preferably 0.1% by mass, but is not limited thereto.

The copper alloy according to the third embodiment is the same as the melting step S01 and the molten metal in the first embodiment and the second embodiment. The high temperature holding step S02 and the casting step S03 are manufactured.

In the melting step S01, it is preferred to use a raw material having a small content of Mn and Ta. In particular, since the possibility that the Mn element is mixed by the iron-based raw material or the like is high, it is preferable to use the iron-based raw material strictly. It is preferable to use a Fe raw material having Mn of 0.1% by mass or less and Ta of 0.005% by mass or less.

In the present embodiment, the content of C contained as an unavoidable impurity is less than 3 ppm by mass, the content of Mn is 20 ppm by mass or less, and the content of Ta is 1 ppm by mass or less. Therefore, the liquid phase separation of the copper alloy melt can be suppressed, and the formation of the iron alloy particles containing Fe and C can be suppressed, and the occurrence of surface defects can be greatly reduced. Moreover, the shape defect of a product can be suppressed.

In the above, the method of producing the copper alloy, the copper alloy sheet, and the copper alloy according to the embodiment of the present invention is described, but the present invention is not limited thereto, and can be appropriately modified without departing from the scope of the technical idea of the present invention.

For example, a copper melt is melted to form a copper melt, and various elements are added to the copper melt. However, the present invention is not limited thereto, and the scrap steel raw material or the like may be melted to prepare a component.

Further, in the present embodiment, the case where the high temperature holding step S02 is provided has been described. However, the present invention is not limited thereto, and the content of C may be reduced by other means. For example, the incorporation of the C element can be prevented by strictly selecting the raw materials used. Since the possibility that the C element is mixed by the iron-based raw material or the like is high, it is preferable to use the iron-based raw material strictly.

In addition, in the third embodiment, Ni: 0.003 mass% or more and 0.5 mass% or less, and Sn: 0.003 mass% or more and 0.5 mass% or less may be contained, and further, it may be 0.0007 mass% or more and 0.5 mass. In the range of % or less, at least one or two or more of Mg, Ca, Sr, Ba, a rare earth element, Zr, Si, Al, Be, Ti, and Co are contained.

[Examples]

Hereinafter, the results of the confirmation experiment performed to confirm the effects of the present invention will be described.

(Example 1)

A copper raw material composed of oxygen-free copper (ASTM B152 C10100) having a purity of 99.99% by mass or more and a C content of 1 ppm by mass or less is prepared, and this is placed in a crucible made of alumina, and is set to a high cycle of an Ar atmosphere. The melting furnace is used for melting.

In the obtained copper melt, pure iron, Cu-Zn master alloy, Cu-Ni master alloy, Cu-Sn master alloy, Cu-P master alloy, and Mg, Ca, Sr, as raw materials are added as needed. Raw materials or master alloys of Ba, rare earth elements, Zr, Si, Al, Be, Ti, Co, which are melted at 1200 ° C in an Ar atmosphere, are prepared into the composition shown in Table 1, and poured into a water-cooled copper mold. To make the ingot. In addition, the C content of each raw material is 10 mass ppm or less. The size of the ingot produced was set to a thickness of about 30 mm, a width of about 150 mm, and a length of about 200 mm. Still, in the present invention example 1 In 27, high-purity iron (purity of 99.99% by mass) was used as an iron raw material.

Further, in Inventive Examples 23 to 26, the obtained melt was once heated from 1200 ° C to 1300 ° C, and then an ingot was produced.

The cooling rate from 1300 ° C to 900 ° C when the melt temperature is 1300 ° C and the cooling rate from 1200 ° C to 900 ° C when the melt temperature is 1200 ° C is set to be about 10 ° C / s or more. .

Further, in Comparative Examples 1 and 2, C powder was added and the amount of C was increased by contact with the melt.

The obtained ingot was heated to 950 ° C and subjected to hot rolling until a thickness of 5.0 mm. After the hot rolling, surface grinding was performed to remove the oxide film, and the thickness was 4.0 mm.

Thereafter, the rough rolling was performed to have a thickness of 0.4 mm. Next, a heating step of 550 ° C × 1 hour was carried out, and further, cold rolling was performed to have a thickness of 0.2 mm.

Next, a heating step of 450 ° C × 1 hour was carried out, and final cold rolling was performed to prepare a bar having a thickness of about 0.1 mm × a width of about 150 mm.

Further, as a final annealing, a heating step of 250 ° C × 1 hour was carried out, and the obtained bar was used as a bar for property evaluation. Here, all of the above heat treatments are carried out in an Ar atmosphere.

The following characteristics evaluation was carried out using the obtained property evaluation bar.

(Method for measuring Fe, P, Zn, other added elements and impurity content)

In the composition of Table 1, Fe, P, Zn, and other additive elements were measured using a glow discharge mass spectrometer (GD-MS), and C was measured by an infrared absorption method.

(mechanical properties)

According to JIS Z 2241:2011 (according to ISO 6892-1:2009), sample No. 13B was sampled from the bar for property evaluation, and 0.2% proof force was measured by an offset method.

Further, the test piece was sampled in such a manner that the stretching direction of the tensile test was parallel with respect to the rolling direction of the bar for property evaluation.

(number of defects)

In the bar for property evaluation, the number of surface defects having a length of 200 μm or more formed by exposing foreign matter to the surface was examined for 25 pieces of copper strips of 0.2 m ² . The length of the defect is set by the maximum length of the rolling direction of the surface flaw of the foreign matter exposed on the surface. The number of average defects (number/m ² ) was calculated by the above evaluation method.

The evaluation results are shown in Table 1.

In Comparative Examples 1 and 2 in which the content of C which is unavoidable impurities is more than the range of the present invention, the number of defects is extremely large, 11.2 / m ² and 11.0 / m ² .

In contrast, in the case of Example 1-27 of the present invention in which the content of C of the unavoidable impurities was less than 3 ppm by mass, the number of defects was 4.4/m ² or less, which was confirmed as compared with the comparative example. Significantly reduced.

Further, in Examples 8-22 and 24-26 of the present invention in which Mg, Ca, Sr, Ba, a rare earth element, Zr, Si, Al, Be, Ti, and Co were added, 0.2% of the endurance was about 500 MPa, and it was confirmed. Increase in strength characteristics.

Further, the copper alloy melt was held at 1300 ° C to prepare an ingot, and in the inventive examples 23 to 26 in which the high temperature of the melt was maintained, the number of defects was further reduced. From this, it was confirmed that the surface defects of the copper alloy sheet can be further suppressed by performing high temperature retention of the copper alloy melt.

(Example 2)

A copper raw material composed of oxygen-free copper (ASTM B152 C10100) having a purity of 99.99% by mass or more, a C content of 1 ppm by mass or less, a Mn content of 0.1 ppm by mass or less, and a Ta content of 0.1 ppm by mass or less is prepared. This was placed in an alumina crucible and melted by a high-frequency melting furnace set to an Ar atmosphere.

In the obtained copper melt, pure iron, Fe-Mn master alloy, Fe-Ta master alloy, Cu-Zn master alloy, Cu-Ni master alloy, Cu-Sn master alloy, Cu as a raw material are added as needed. -P master alloy, and raw materials or master alloys of Mg, Ca, Sr, Ba, rare earth elements, Zr, Si, Al, Be, Ti, Co, and the same method as in Example 1 were prepared as shown in Table 2. An ingot of the composition shown (thickness about 30 mm x width about 150 mm x length about 200 mm). Further, in Inventive Examples 39 to 41, the obtained melt was once heated from 1200 ° C to 1300 ° C, and then an ingot was produced.

Using this ingot, a property evaluation bar having a thickness of about 0.1 mm and a width of about 150 mm was produced in the same manner as in Example 1.

The following characteristics evaluation was carried out using the obtained property evaluation bar.

In addition, the number of defects is evaluated in more detail. Therefore, the front and back sides of 50 sheets of 0.2 m ² copper strips are observed from the bar for characteristic evaluation, and the surface having a length of 200 μm or more formed by the foreign matter exposed on the surface is inspected. The number of defects. The length of the defect is set by the maximum length of the rolling direction of the surface flaw of the foreign matter exposed on the surface. The number of average defects (number/m ² ) was calculated by the above evaluation method.

(Method for measuring Fe, P, Zn, Mn, Ta, other added elements and impurity content)

Fe, P, and Zn were measured using an inductively coupled plasma luminescence spectrometer (ICP-AES). Mn, Ta, and other additive elements were measured using a glow discharge mass spectrometer (GD-MS).

C is measured by an infrared absorption method.

The evaluation results are shown in Table 2.

In Examples 35 to 41 of the present invention in which the content of Mn which is an unavoidable impurity is 20 ppm by mass or less and the content of Ta is 1 ppm by mass or less, the number of average defects is further reduced.

From this, it was confirmed that the surface defect of the copper alloy sheet can be further suppressed by setting the content of Mn of the unavoidable impurities to 20 ppm by mass or less and the content of Ta to 1 ppm by mass or less.

[Industry Utilization]

According to the method for producing a copper alloy, a copper alloy sheet, and a copper alloy according to the present invention, surface defects and shape defects in the Cu-Fe-P alloy can be suppressed.

Claims (5)

A copper alloy sheet comprising a copper alloy containing Fe: 1.5% by mass or more and 2.7% by mass or less, P: 0.008% by mass or more and 0.15% by mass or less, and Zn: 0.01% by mass or more and 0.5% by mass or less. Further, the residual portion is Cu and an unavoidable impurity, and the content of C contained as the unavoidable impurity is less than 3 ppm by mass, the content of Mn is 20 ppm by mass or less, and the content of Ta is 1 ppm by mass. In the copper alloy sheet, the surface defects having a length of 200 μm or more formed by exposing the iron alloy particles containing Fe and C to the surface are 5/m ² or less. The copper alloy sheet according to claim 1, which further contains Ni: 0.003 mass% or more and 0.5 mass% or less, and Sn: 0.003 mass% or more and 0.5 mass% or less. The copper alloy sheet according to claim 1 or claim 2, further comprising Mg, Ca, Sr, Ba, a rare earth element, Zr, Si, Al, Be, Ti in a range of 0.0007 mass% or more and 0.5 mass% or less. At least one or two or more of Co. The copper alloy sheet according to claim 1, wherein the thickness of the thin plate is 0.5 mm or less. A method for producing a copper alloy sheet, the method for producing a copper alloy sheet according to any one of claims 1 to 3, comprising the steps of: melting a raw material to form a copper alloy melt, and melting the copper alloy melt The liquid is held at a high temperature holding step of 1300 ° C or higher, and the molten copper alloy which is kept at 1300 ° C or higher is supplied into the mold to obtain a casting step of the ingot.