TW201718888A - Copper alloy for electric and electronic device, copper alloy sheet for electric and electronic device, conductive component for electric and electronic device, and terminal - Google Patents

Abstract

The present invention relates to a copper alloy for electric and electronic device. The copper alloy includes more than 2 mass% to 36.5 mass% of Zn; 0.1 mass% to 0.9 mass% of Sn; 0.15 mass% to less than 1.0 mass% of Ni; 0.005 mass% to 0.1 mass% of P; 0.001 mass% to 0.1 mass% of Fe; and a remainder comprising Cu and unavoidable impurities, in which 3 < (Ni+Fe)/P < 30, 0.3 < Sn/(Ni+Fe) < 2.7, and 0.002 ≤ [Fe/Ni]<0.6 are satisfied by atomic ratio, and atomic ratio [Fe/Ni]P of Fe to Ni in an [Ni,Fe]-P-based precipitate containing Fe, Ni, and P and atomic ratio [Fe/Ni] of Fe to Ni in the entire amount of copper alloy are satisfied 5 ≤ [Fe/Ni]P/[Fe/Ni] ≤ 200.

Description

Copper alloys for electronic and electrical equipment, copper alloy sheets for electronic and electrical equipment, conductive members and terminals for electronic and electrical equipment

The present invention relates to a Cu-Zn-Sn-based electronic ‧ electrical used as a connector for a semiconductor device, and other terminals, a movable conductive sheet of an electromagnetic relay, and a conductive member for an electronic/electrical device such as a lead frame Copper alloy for machine, copper alloy sheet for electronic and electrical equipment, electronic components, conductive members and terminals for electrical equipment.

The present application claims priority based on Japanese Patent Application No. 2015-150338, filed on Jan.

As the above-mentioned electronic and electrical conductive member, a Cu-Zn alloy has been widely used from the viewpoint of balance of strength, workability, and cost.

Moreover, in the case of a terminal such as a connector, in order to improve the other side The reliability of the contact of the conductive member is applied to the surface of the substrate (primary sheet) made of the Cu-Zn alloy by tin (Sn) plating. When a Cu-Zn alloy is used as a substrate and a conductive member such as a Sn-plated connector is applied to the surface thereof, in order to improve the recyclability of the Sn plating material and at the same time increase the strength, Cu-Zn- is used. Sn alloy.

Here, for example, a conductive member for an electric or electrical device such as a connector is generally formed into a predetermined shape by punching a thin plate (rolled sheet) having a thickness of about 0.05 to 3.0 mm, and at least A part is applied to the bending process to manufacture. In this case, the other side conductive member is brought into contact in the vicinity of the bent portion so that electrical connection with the other side conductive member can be obtained while maintaining the contact state with the other side conductive member by the spring property of the bent portion. Way to use.

Heat resistance and stress relaxation resistance are required in the case where a connector such as a connector that is bent and processed to maintain a contact state with the other side conductive material in the vicinity of the bent portion is applied. Excellent.

Then, for example, in Patent Documents 1 to 4, a method for improving the heat resistance and stress relaxation resistance of the Cu-Zn-Sn-based alloy is proposed.

Patent Document 1 discloses that the Ni-P-based compound is formed by containing Ni in the Cu-Zn-Sn-based alloy, whereby the stress relaxation resistance is improved, and the addition of Fe is also resistant to stress relaxation. Promote to be effective.

Patent Document 2 discloses that Ni, Fe, and P are added together in a Cu-Zn-Sn-based alloy to form a compound, so that strength and elasticity can be obtained. Increased heat and heat resistance.

Further, Patent Document 3 discloses that the addition of Ni to the Cu-Zn-Sn-based alloy while adjusting the Ni/Sn ratio within a specific range improves the stress relaxation resistance, and also describes that the trace addition of Fe is also The improvement of stress relaxation resistance is effective.

Further, in Patent Document 4, which is a target of a lead frame material, Ni and Fe are added together with P in the Cu-Zn-Sn-based alloy, and the atomic ratio of (Fe+Ni)/P is adjusted to 0.2 to 3. In the range, it is possible to form an Fe-P-based compound, a Ni-P-based compound, or an Fe-Ni-P-based compound to improve the stress relaxation resistance.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 5-33087

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2006-283060

[Patent Document 3] Japanese Patent No. 3953357

[Patent Document 4] Japanese Patent No. 3717321

However, in order to further reduce the size and weight of electronic and electrical equipment, the use of copper alloys for electronic and electrical equipment for conductive members for electronic and electrical equipment has required further strength, bending workability, heat resistance, and Improved stress relaxation resistance.

However, in Patent Documents 1 and 2, only the content of each of Ni, Fe, and P is considered, and only the adjustment of such individual content is not necessarily required to reliably and sufficiently improve the stress relaxation resistance.

Further, although Patent Document 3 discloses that the Ni/Sn ratio is adjusted, the relationship between the P compound and the stress relaxation resistance is not considered at all.

Further, in Patent Document 4, only the total amount of Fe, Ni, and P and the atomic ratio of (Fe + Ni) / P are adjusted, and although the heat resistance can be improved, the stress relaxation resistance can not be sufficiently improved.

As described above, in the conventionally proposed method, the heat resistance and stress relaxation resistance of the Cu—Zn—Sn-based alloy cannot be sufficiently improved. Therefore, in the connector or the like having the above-described structure, the residual stress is relaxed and the contact pressure with the other conductive member cannot be maintained in a long-term, particularly high-temperature environment, and an abnormality such as contact failure is likely to occur at an early stage. problem. In order to avoid such problems, it has been necessary to increase the thickness of the material in the past, resulting in an increase in material cost and an increase in weight. Thus, a further improvement in heat resistance and stress relaxation resistance is desired.

The present invention has been made in view of the above-described circumstances, and it is an object of the present invention that the heat resistance and the stress relaxation resistance are excellent and sufficient, and the strength is excellent, the copper alloy for electric and electronic equipment, and the electrons using the same. ‧ Copper alloy sheets for electrical equipment, conductive members and terminals for electronic and electrical equipment.

The inventor has made continuous efforts to experiment and ‧ research Now, by adding an appropriate amount of Ni, P, and Fe in the Cu-Zn-Sn-based alloy, the Fe/Ni ratio in the [Ni,Fe]-P-based precipitate precipitated by the heat treatment conditions is the Fe/Ni ratio of the alloy as a whole. When the Ni ratio is adjusted to an appropriate range, the copper alloy having excellent strength and bending workability can be obtained while the heat resistance and the stress relaxation resistance are reliably and sufficiently improved.

Similarly, it was found that the addition of Ni, P, Fe, and Co in the Cu-Zn-Sn-based alloy and the (Fe+Co)/Ni ratio in the [Ni,(Co,Fe)]-P-based precipitates When the (Fe+Co)/Ni ratio of the entire alloy is adjusted to an appropriate range, the copper alloy excellent in strength and bending workability can be obtained while the heat resistance and the stress relaxation resistance are reliably and sufficiently improved.

The present invention has been completed based on the findings of such.

The copper alloy for electric and electrical equipment according to the present invention is characterized by containing more than 2 mass% and 36.5 mass% or less of Zn, 0.1 mass% or more and 0.9 mass% or less of Sn, 0.15 mass% or more, and less than 1.0 mass%. Ni, 0.005 mass% or more and 0.1 mass% or less of P, 0.001 mass% or more and 0.1 mass% or less of Fe, the remainder is made of Cu and unavoidable impurities; the total content of Ni and Fe and the content of P The ratio (Ni+Fe)/P is such that the atomic ratio satisfies 3<(Ni+Fe)/P<30, and the ratio of the content of Sn to the total content of Ni and Fe is Sn/(Ni+Fe). The atomic ratio is such that 0.3<Sn/(Ni+Fe)<2.7 is satisfied, and the ratio of the content of Fe to the content of Ni [Fe/Ni] is 0.002 ≦[Fe/Ni]<0.6 in atomic ratio; Further, in the parent phase, there is a [Ni,Fe]-P-based precipitate containing Fe, Ni and P, and an atomic ratio of the content of Fe in the Ni-Fe-P-based precipitate to the content of Ni. [Fe/Ni] _P , the atomic ratio [Fe/Ni] of the content of Fe to the content of Ni in the entire alloy satisfies 5 ≦ [Fe/Ni] _P / [Fe/Ni] ≦ 200.

According to the copper alloy for electric and electric equipment configured as described above, Ni and Fe are added together with P, and the addition ratio of Sn, Ni, Fe, and P is restricted, and the precipitate is precipitated from the parent phase (α phase main body). A [Ni,Fe]-P-based precipitate containing Ni and Fe and P. In this case, the atomic ratio [Fe/Ni] _P of the content of Fe in the [Ni,Fe]-P-based precipitate and the content of Ni in the entire alloy and the content of Ni in the alloy. The atomic ratio [Fe/Ni] satisfies 5≦[Fe/Ni] _P /[Fe/Ni]≦200, so that the number density of [Ni,Fe]-P-based precipitates in the alloy can be ensured. The coarsening of the precipitates is suppressed, and the heat resistance and the stress relaxation resistance are excellent.

Here, the "Ni,Fe]-P-based precipitate refers to a ternary precipitate of Ni-Fe-P, and further includes Cu, Zn, Sn containing other elements such as a main component. Multicomponent precipitates of impurities such as O, S, C, Cr, Mo, Mn, Mg, Zr, Ti, and the like. Further, the [Ni, Fe]-P-based precipitates are present in the form of a phosphide or an alloy in which phosphorus is dissolved.

Further, the copper alloy for electric and electric equipment according to the present invention is characterized by containing more than 2 mass% and 36.5 mass% or less of Zn, 0.1 mass% or more and 0.9 mass% or less of Sn, 0.15 mass% or more, and less than 1.0. When the mass% of Ni, 0.005 mass% or more, and 0.1 mass% or less of P, the content of Fe and Co, and the total content of Fe and Co are 0.001 mass% or more and 0.1 mass% or less (however, it contains 0.001 mass% or more). And 0.1 mass% or less of Fe), the remainder is formed by Cu and unavoidable impurities; the ratio of the total content of Ni, Fe, and Co to the content of P (Ni + Fe + Co) / P is determined by atomic ratio Satisfying 3<(Ni+Fe+Co)/P<30, and the ratio of the content of Sn to the total content of Ni, Fe, and Co, Sn/(Ni+Fe+Co), is 0.3<Sn in atomic ratio. /(Ni+Fe+Co)<2.7, and the ratio of the total content of Fe and Co to the content of Ni (Fe+Co)/Ni is 0.002≦(Fe+Co)/Ni<0.6 in atomic ratio. Further, in the parent phase, at least one of Fe and Co, and [Ni, (Fe, Co)]-P-based precipitates containing Ni and P, and [Ni, (Fe, Co)]-P system are contained. the total content of precipitates of Fe and Co and the atomic ratio of Ni content of [(Fe + Co) / Ni] _P, with respect to The total content of gold overall Fe and Co with a content of Ni in the atomic ratio [(Fe + Co) / Ni] to satisfy 5 ≦ [(Fe + Co) / Ni] _P / [(Fe + Co) / Ni 〕 ≦ 200.

According to the above-mentioned copper alloy for electric and electric equipment, Ni is added together with P, and Fe and Co are simultaneously added, and the ratio of addition of Sn, Ni, Fe, Co, and P is restricted, and the mother phase (α phase) is provided. At least one or more of Fe and Co precipitated in the main body and [Ni, (Fe, Co)]-P-based precipitates of Ni and P. Here, the atomic ratio of the total content of Fe and Co in the [Ni,(Fe,Co)]-P-based precipitate to the content of Ni [(Fe+Co)/Ni] _{P is} relative to the alloy. The atomic ratio of the total content of Fe and Co to the content of Ni [(Fe + Co) / Ni] satisfies 5 ≦ [(Fe + Co) / Ni] _P / [(Fe + Co) / Ni] Since ≦200, the number density of [Ni,(Fe,Co)]-P-based precipitates in the alloy can be ensured, and the coarsening of precipitates can be suppressed, and the heat resistance and stress relaxation resistance are excellent.

Further, the "Ni, (Fe, Co)]-P-based precipitate referred to herein means a ternary precipitate of Ni-Fe-P or Ni-Co-P or a Ni-Fe-Co-P 4 Metaphase precipitates further include multicomponent precipitation of O, S, C, Cr, Mo, Mn, Mg, Zr, Ti, etc. containing other elements such as Cu, Zn, Sn, and impurities of the main component. Things. Further, the [Ni, (Fe, Co)]-P-based precipitates are present in the form of a phosphide or an alloy in which phosphorus is dissolved.

In the copper alloy for electric and electric equipment of the present invention, it is preferable to set the average particle diameter of the [Ni,Fe]-P-based precipitate containing Fe, Ni and P to be 100 nm or less.

Further, in the copper alloy for electric and electric equipment of the present invention, the average particle diameter of the [Ni, (Fe, Co)]-P-based precipitate containing at least one of Fe and Co and Ni and P is set to It is preferably 100 nm or less.

In such a case, the average particle diameter of the [Ni,Fe]-P-based precipitate containing Fe, Ni and P, or at least one or more of Fe and Co, and Ni and P are set [Ni, (Fe). Since the average particle diameter of the (P)-P-precipitate is 100 nm or less, fine [Ni,Fe]-P-based precipitates or [Ni,(Fe,Co)]-P-based precipitates are sufficient. The number density is distributed so that heat resistance and stress relaxation resistance can be surely improved.

The copper alloy sheet for an electric/electrical device according to the present invention is characterized by being formed of the above-mentioned rolled material of a copper alloy for electric and electric equipment, and having a thickness of 0.05 mm or more and 3.0 mm or less.

Such a thickness of rolled sheet (bar) is suitable for use in even Connectors, other terminals, movable conductive sheets of electromagnetic relays, lead frames, etc.

The conductive member for an electric/electrical device according to the present invention is characterized by being made of the above-described copper alloy sheet for an electric/electrical machine. In the present invention, the conductive member for an electric/electrical device according to the present invention means a terminal, a connector, a relay, a lead frame, or the like.

The terminal of the present invention is characterized by the above-described copper alloy sheet for electronic and electrical equipment. Further, the terminal in the present invention includes a connector or the like.

The conductive members and terminals for electronic and electrical equipment which are configured as described above are particularly excellent in heat resistance and stress relaxation resistance, so that they can be used satisfactorily even in a high temperature environment.

According to the present invention, it is possible to provide a copper alloy for electronic and electrical equipment which is excellent in heat resistance and stress relaxation resistance, and which is excellent in strength and excellent in strength, and a copper alloy sheet for electronic and electrical equipment using the same, and an electric appliance. Conductive members and terminals for machines.

Fig. 1 is a flow chart showing an example of the steps of a method for producing a copper alloy for an electric/electrical machine according to the present invention.

[Best Mode for Carrying Out the Invention]

Next, a copper alloy for an electric/electrical machine according to an embodiment of the present invention will be described.

The copper alloy for electric and electric equipment according to the present embodiment has a composition containing more than 2 mass% and 36.5 mass% or less of Zn, 0.1 mass% or more and 0.9 mass% or less of Sn, 0.15 mass% or more, and less than 1.0 mass. % of Ni, 0.005 mass% or more and 0.1 mass% or less of P, 0.001 mass% or more and 0.1 mass% or less of Fe, and the remainder is made of Cu and unavoidable impurities.

Then, the ratio of the content of each alloy element to each other is determined by the ratio of the total content of Ni and Fe to the content of P (Ni + Fe) / P in terms of atomic ratio (1) 3<(Ni+Fe)/P<30‧‧‧(1)

Further, the ratio of the content of Sn to the total content of Ni and Fe is Sn/(Ni + Fe) in terms of atomic ratio, which satisfies the following formula (2): 0.3 < Sn / (Ni + Fe) < 2.7 ‧ ‧ (2 )

At the same time, the ratio of the content of Fe to the content of Ni is Fe/Ni in an atomic ratio of 0.002 ≦Fe/Ni<0.6‧‧(3) which satisfies the following formula (3).

In the copper alloy for electric and electric equipment according to the present embodiment, [Ni,Fe]-P-based precipitates containing Fe, Ni, and P are present in the matrix phase, and the [Ni, Fe]-P precipitates. The atomic ratio [Fe/Ni] _P of the content of Fe to the content of Ni in the material, and the atomic ratio [Fe/Ni] of the content of Fe to the content of Ni in the entire alloy satisfy the following (4) ) 5≦[Fe/Ni] _P /[Fe/Ni]≦200‧‧‧(4).

Further, in the copper alloy for electric and electric equipment according to the present embodiment, Co may be contained in addition to the above-mentioned Zn, Sn, Ni, P, and Fe. In this case, the total content of Fe and Co is set to be 0.001 mass% or more and 0.1 mass% or less (however, Fe is contained in an amount of 0.001 mass% or more and 0.1 mass% or less).

In this case, the ratio of the content of each alloy element to each other is determined by the ratio of the total content of Ni, Fe, and Co to the content of P (Ni+Fe+Co)/P in terms of atomic ratio. The following (1') formula 3 <(Ni+Fe+Co)/P<30‧‧‧(1')

Further, the ratio of the content of Sn to the total content of Ni, Fe, and Co is such that Sn/(Ni+Fe+Co) satisfies the following (2') formula: 0.3<Sn/(Ni+Fe+Co) in terms of atomic ratio. <2.7‧‧‧(2')

Further, the ratio of the total content of Fe and Co to the content of Ni (Fe + Co) / Ni is in the atomic ratio, and satisfies the following (3') formula: 0.002 ≦ (Fe + Co) / Ni < 0.6 ‧ ‧ ( 3').

In the case where Co is added, at least one of Fe and Co, and [Ni, (Fe, Co)]-P-based precipitates containing Ni and P are present in the parent phase, [Ni, (Fe, Co) The atomic ratio of the total content of Fe and Co in the P-precipitate to the content of Ni [(Fe+Co)/Ni] _P , the total content of Fe and Co in the entire alloy, and the content of Ni. The atomic ratio [(Fe+Co)/Ni] is the following formula (4'): 5≦[(Fe+Co)/Ni] _P /[(Fe+Co)/Ni]≦200‧‧‧( 4').

Here, the reason why the composition of the alloy and the composition in the precipitate are as defined above will be described below.

(Zn: more than 2 mass% and 36.5 mass% or less)

Zn is a basic alloying element in the copper alloy to be used in the present embodiment, and is an effective element for improving strength and spring characteristics. Moreover, since Zn is cheaper than Cu, it is also effective in reducing the material cost of the copper alloy. When Zn is 2 mass% or less, the effect of reducing the material cost cannot be sufficiently obtained. On the other hand, when Zn exceeds 36.5 mass%, the corrosion resistance is lowered and the cold rolling property is also lowered.

Therefore, the content of Zn is in a range of more than 2 mass% and 36.5 mass% or less. In addition, the content of Zn is preferably in the range of 5 mass% or more and 33 mass% or less in the above range, and more preferably in the range of 7 mass% or more and 27 mass% or less. It is preferably in the range of 7 mass% or more and 12 mass% or less.

(Sn: 0.1 mass% or more and 0.9 mass% or less)

The addition of Sn is effective for strength improvement and contributes to the improvement of the recyclability of the Cu-Zn alloy material with Sn plating. Further, it has been found by the inventors of the present invention that when Sn and Ni coexist, the stress relaxation resistance is also improved. If Sn is less than 0.1 mass%, the effects cannot be sufficiently obtained. On the other hand, when Sn exceeds 0.9 mass%, the hot inter-processability and the cold inter-rollability are lowered, and there is a calendering between cold or cold. The rupture of the rupture occurs under rolling, so that the electrical conductivity is also lowered.

Therefore, the content of Sn is in a range of 0.1 mass% or more and 0.9 mass% or less. In addition, the content of Sn is preferably in the range of 0.2 mass% or more and 0.8 mass% or less, even in the above range.

(Ni: 0.15 mass% or more and less than 1.0 mass%)

By adding Ni together with P, the Ni-P-based precipitates can be precipitated from the parent phase (α phase host), and by adding with Fe and P, the [Ni,Fe]-P-based precipitates can be obtained. Precipitation in the parent phase (α phase host), by adding Fe and Co together with P, the [Ni, (Fe, Co)]-P system precipitates can be Precipitated in the parent phase (α phase body). By the effect of the Ni-P-based precipitates, the [Ni,Fe]-P-based precipitates, and the [Ni,(Fe,Co)]-P-based precipitates on the grain boundary obtained during recrystallization, The average crystal grain size can be controlled, and the strength, bending workability, and stress corrosion cracking resistance can be improved. Further, the presence of the precipitates and the like can greatly improve the stress relaxation resistance. Further, since Ni is made to coexist with Sn, Fe, P, and Co required for the reaction, the stress relaxation resistance can be improved even by solid solution strengthening. On the other hand, when the amount of Ni added is less than 0.15 mass%, the stress relaxation resistance cannot be sufficiently improved. On the other hand, when the amount of Ni added is 1.0 mass% or more, the amount of solid solution Ni is increased to lower the electrical conductivity, and the cost is increased due to an increase in the amount of expensive Ni raw material used.

Therefore, the content of Ni is in the range of 0.15 mass% or more and less than 1.0 mass%. Further, the content of Ni is preferably in the above range, and particularly preferably in the range of 0.2 mass% or more and less than 0.8 mass%.

(P: 0.005 mass% or more and 0.1 mass% or less)

P and Ni have high binding property. When an appropriate amount of P is contained together with Ni, Ni-P-based precipitates can be precipitated, and by adding with Fe and P, [Ni,Fe]-P-based precipitates can be obtained. Precipitation from the parent phase (α phase main body), and addition of Fe and Co together with P, can precipitate [Ni, (Fe, Co)]-P-based precipitates from the parent phase (α phase main body). By the presence of such Ni-P-based precipitates, [Ni,Fe]-P-based precipitates, and [Ni,(Fe,Co)]-P-based precipitates, the stress relaxation resistance can be improved. Here, if the amount of P is not full When it is 0.005 mass%, it is difficult to sufficiently precipitate the Ni-P-based precipitates, the [Ni,Fe]-P-based precipitates, and the [Ni,(Fe,Co)]-P-based precipitates. The stress relaxation characteristics are sufficiently improved. On the other hand, when the amount of P exceeds 0.1 mass%, the amount of P solid solution in the alloy increases, and the electrical conductivity is lowered, and the rolling property is also lowered, and the inter-cold rolling fracture is likely to occur.

Therefore, the content of P is set to be in the range of 0.005 mass% or more and 0.1 mass% or less. The content of P is preferably in the above range, and particularly preferably in the range of 0.01 mass% or more and 0.08 mass% or less.

In many cases, P is an element that is inevitably mixed from the melting raw material of the copper alloy. Therefore, when the content of P is limited as described above, it is necessary to appropriately select the molten raw material.

(Fe: 0.001 mass% or more and 0.1 mass% or less)

When Fe is added together with Ni and P, the [Ni,Fe]-P-based precipitate can be precipitated from the parent phase (α phase host), and by adding a small amount of Co, [Ni, (Fe, Co) can be obtained. )] - The P-based precipitate is precipitated from the parent phase (α phase body). The average crystal grain size can be controlled by the effect of the [Ni,Fe]-P-based precipitate or the [Ni,(Fe,Co)]-P-based precipitate on the grain boundary obtained during recrystallization. The strength, bending workability, and stress corrosion cracking resistance can be improved. Further, by the presence of precipitates such as this, the two characteristics of stress relaxation resistance and heat resistance can be greatly improved. Here, if the content of Fe is less than 0.001 mass%, the stress-resistant pine added by Fe cannot be obtained. The lifting effect of the two characteristics of relaxation and heat resistance. On the other hand, when the content of Fe exceeds 0.1 mass%, the effect of improving both stress relaxation resistance and heat resistance cannot be obtained, and the amount of solid solution Fe is increased to lower the electrical conductivity, and the cold rolling property is also lowered. .

In the case where Fe is added in the present embodiment, the Fe content is in a range of 0.001 mass% or more and 0.1 mass% or less. In addition, the content of Fe is preferably in the range of 0.002 mass% or more and 0.08 mass% or less, even in the above range.

(Total content of Fe and Co: 0.001 mass% or more and 0.1 mass% or less)

When Co is added, it is considered that a part of Fe is substituted with Co. By adding Fe and Co, the [Ni, (Fe, Co)]-P-based precipitate can be precipitated from the parent phase (α phase host). By controlling the effect of the pinned grain boundary obtained by the [Ni, (Fe, Co)]-P-based precipitate on recrystallization, the average crystal grain size can be controlled, and the strength, bending workability, and stress corrosion resistance can be obtained. Increased rupture. Further, by the presence of the [Ni,(Fe,Co)]-P-based precipitate, the two characteristics of stress relaxation resistance and heat resistance can be greatly improved. When the total content of Fe and Co is less than 0.001 mass%, the effect of improving the stress relaxation resistance and the heat resistance by the addition of Fe and Co cannot be sufficiently obtained. On the other hand, when the total content of Fe and Co exceeds 0.1 mass%, not only the effect of improving stress relaxation resistance and heat resistance is further improved, but also the solid solution Fe and the solid solution Co are increased to cause conductivity. Reduced, and the cold ductility is also reduced.

In the present embodiment, when both Fe and Co are added, the content of Fe is 0.001 mass% or more and 0.1 mass% or less, and the total content of Fe and Co is 0.001 mass%. Above and within the range of 0.1 mass% or less. In addition, the total content of Fe and Co is preferably in the range of 0.002 mass% or more and 0.08 mass% or less, even in the above range.

The remainder of each of the above elements is basically Cu and an unavoidable impurity. Here, examples of the unavoidable impurities include Co, Al, Ag, B, Ba, Hf, V, Nb, Ta, Mo, W, Re, Ru, Os, O, S, Se, Rh, Ir, Pd, Pt, Au, Cd, Ga, In, Li, Ge, As, Sb, Tl, Pb, Bi, C, Be, N, H, Hg, Mg, Ti, Cr, Zr, Ca, Sr, Y, Mn, Te, Si, Sc and rare earth elements. Such unavoidable impurities are preferably used in a small amount, and even when waste is used as a raw material, the total amount is preferably 0.3 mass% or less. The desirable total amount of the unavoidable impurities is 0.2 mass% or less, and the most desirable total amount is 0.1 mass% or less.

Further, in the copper alloy for electric and electric equipment of the present embodiment, not only the respective addition amount ranges of the respective alloy elements are adjusted as described above, but it is important that the ratio of the respective elements is proportional to each other in terms of atomic ratio. The method of satisfying the above formulas (1) to (4) is limited. Further, when Co is added, it is important to satisfy the method of (1') to (4'). Therefore, the reasons for limiting the formulas (1) to (4) and (1') to (4') will be described below.

(1) Formula: 3<(Ni+Fe)/P<30

When the ratio of (Ni + Fe) / P is 3 or less, the ratio of the solid solution P increases, the stress relaxation resistance and the heat resistance are lowered, and at the same time, the conductivity is lowered due to the solid solution P, and the calendering property is also When it is lowered, it is easy to cause cold rolling fracture, and the bending workability is also lowered. On the other hand, when the (Ni+Fe)/P ratio is 30 or more, the ratio of the Ni and Fe which are solid-solved increases, and the electrical conductivity decreases, and the amount of expensive Ni raw materials is relatively changed. More, resulting in higher costs. Thus, the (Ni + Fe) / P ratio is limited to the above range. Further, the ratio of (Ni + Fe) / P is preferably in the range of more than 3 and not more than 20 in the above range. More preferably, it is more than 3 and 15 or less.

(2) Formula: 0.3<Sn/(Ni+Fe)<2.7

When the Sn/(Ni+Fe) ratio is 0.3 or less, sufficient stress relaxation resistance and heat resistance improvement effect cannot be exhibited. On the other hand, when the Sn/(Ni+Fe) ratio is 2.7 or more, the relative ratio is relatively When the amount of Ni is small, the amount of Ni-P-based precipitates is reduced, and the improvement of both the stress relaxation resistance and the heat resistance cannot be obtained. Thus, the Sn/(Ni+Fe) ratio is limited to the above range.

Further, the Sn/(Ni + Fe) ratio is preferably in the range of more than 0.3 and not more than 1.5, even within the above range.

(3) Formula: 0.002≦Fe/Ni<0.6

If the Fe/Ni ratio is less than 0.002, the amount of raw material used for expensive Ni is also relatively increased while the strength is lowered, resulting in an increase in cost. On the other hand, when the Fe/Ni ratio is 0.6 or more, sufficient stress relaxation resistance and heat resistance improvement effect cannot be exhibited. Thus, the Fe/Ni ratio is limited to the above range. Further, the Fe/Ni ratio is preferably in the range of 0.002 or more and 0.4 or less, even within the above range. More preferably, it is in the range of 0.002 or more and 0.2 or less.

(4) Formula: 5≦[Fe/Ni] _P /[Fe/Ni]≦200

The atomic ratio [Fe/Ni] _P of the content of Fe in the Ni-Fe]-P-based precipitate to the content of Ni, and the atomic ratio of the content of Fe to the content of Ni in the entire alloy [Fe/ Ni] has also become important. When the ratio of [Fe/Ni] _P /[Fe/Ni] is less than 5, the number density of [Ni,Fe]-P-based precipitates becomes low, and sufficient stress relaxation resistance and heat resistance cannot be obtained. Improvement. On the other hand, when [Fe/Ni] _P / [Fe/Ni] is compared with 200 large, the precipitate will become Fe-P-based precipitates, and the number of precipitates will increase due to the size of the precipitates. Since it becomes low, the improvement of the characteristics of stress relaxation resistance and heat resistance cannot be obtained. Thus, the [Fe/Ni] _P / [Fe/Ni] ratio is limited to the above range. Further, the ratio of [Fe/Ni] _P / [Fe/Ni] is preferably in the range of 10 or more and 100 or less, even in the above range. More preferably, it is more than 15 and 75 or less.

(1'): 3<(Ni+Fe+Co)/P<30

When Fe and Co are added, it is considered that one part of Fe is replaced by Co, and the formula (1') is basically based on the formula (1). Here, if (Ni+ When the Fe+Co)/P ratio is 3 or less, the stress relaxation resistance and the heat resistance are lowered as the ratio of the solid solution P increases, and at the same time, the conductivity is lowered due to the solid solution P, and the rolling property is also lowered. It is easy to cause cold rolling fracture, and the bending workability is also lowered. On the other hand, when the ratio of (Ni+Fe+Co)/P is 30 or more, the ratio of the solid solution of Ni, Fe, and Co increases, and the conductivity is lowered, and the amount of raw material of Co or Ni which is expensive is high. It will also become relatively more, resulting in higher costs. Thus, the (Ni + Fe + Co) / P ratio is limited to the above range. Further, the (Ni + Fe + Co) / P ratio is preferably in the range of more than 3 and not more than 20 in the above range. More preferably, it is more than 3 and 15 or less.

(2'): 0.3<Sn/(Ni+Fe+Co)<2.7

The formula (2') when Fe and Co are added is also in accordance with the above formula (2). When the Sn/(Ni+Fe+Co) ratio is 0.3 or less, sufficient stress relaxation resistance and heat resistance improvement effect cannot be exhibited. On the other hand, when the Sn/(Ni+Fe+Co) ratio is 2.7 or more. In contrast, the amount of (Ni + Fe + Co) is relatively small, and the amount of [Ni, (Fe, Co)] - P-based precipitates is reduced, and the stress relaxation resistance and heat resistance are lowered. Thus, the Sn/(Ni + Fe + Co) ratio is limited to the above range. Further, the Sn/(Ni + Fe + Co) ratio is preferably in the range of more than 0.3 and not more than 1.5, even within the above range.

(3') formula: 0.002 ≦ (Fe + Co) / Ni < 0.6

When Fe and Co are added, the ratio of the total content of Fe and Co to the content of Ni also becomes important. If the (Fe + Co) / Ni ratio is 0.6 In the case of the above, the stress relaxation resistance and the heat resistance are lowered, and the cost is increased due to an increase in the amount of use of the expensive Co raw material. When the (Fe+Co)/Ni ratio is less than 0.002, the amount of raw material used for expensive Ni is relatively large while the strength is lowered, resulting in an increase in cost. Thus, the (Fe + Co) / Ni ratio is limited to the above range. Further, the (Fe + Co) / Ni ratio is preferably in the range of 0.002 or more and 0.4 or less, even within the above range. More preferably, it is 0.002 or more and 0.2 or less.

(4'): 5≦[(Fe+Co)/Ni] _P /[(Fe+Co)/Ni]≦200

When Fe and Co are added, the atomic ratio of the total content of Fe and Co in the [Ni, (Fe, Co)]-P-based precipitate to the content of Ni [(Fe + Co) / Ni] _P , The atomic ratio [(Fe+Co)/Ni] of the total content of Fe and Co to the content of Ni as a whole of the alloy is also important. When the ratio of [(Fe+Co)/Ni] _P /[(Fe+Co)/Ni] is less than 5, the number density of [Ni, (Fe, Co)]-P-based precipitates becomes low. The improvement in stress relaxation resistance and heat resistance cannot be obtained. On the other hand, when [(Fe+Co)/Ni] _P /[(Fe+Co)/Ni] is compared to 200 large, the precipitate will become (Fe, Co)-P-based precipitate, and When the size of the precipitates is increased and the number density is also lowered, the stress relaxation resistance and the heat resistance are not improved.

Thus, the ratio of [(Fe + Co) / Ni ] _P / [(Fe + Co) / Ni] is limited to the above range. Further, the ratio of [(Fe + Co) / Ni] _P / [(Fe + Co) / Ni] is preferably in the range of 10 or more and 100 or less, even in the above range. More preferably, it is more than 15 and 75 or less.

For each of the alloy elements as described above, the ratio of each element is adjusted not only to the individual content but also to the electronic (1) to (3) or (1') to (3') type. In the copper alloy, [Ni,Fe]-P-based precipitates or [Ni,(Fe,Co)]-P-based precipitates are dispersed and precipitated from the parent phase (α-phase body). Then, in order to satisfy the above formula (4) or (4'), the [Ni,Fe]-P-based precipitate or [Ni,(Fe,Co)]-P is restricted by limiting the composition ratio in the precipitate. Since the size of the precipitate is made fine and the number density is ensured, it is considered that the stress relaxation resistance and the heat resistance are improved.

Further, in the present embodiment, the average particle diameter of the [Ni,Fe]-P-based precipitate containing Fe, Ni and P is set to be 100 nm or less. Further, the average particle diameter of the [Ni, (Fe, Co)]-P-based precipitate containing Fe and Co, and Ni and P is set to be 100 nm or less.

In this way, the average particle diameter of the [Ni,Fe]-P-based precipitates and the average particle diameter of the [Ni,(Fe,Co)]-P-based precipitates are made 100 nm or less, and the stress relaxation is considered to be fine. The characteristics and heat resistance can thus be surely improved. The average particle diameter of the precipitate is preferably 5 nm or more and 50 nm or less.

Next, a preferred example of the method for producing a copper alloy for an electric/electrical device according to the above-described embodiment will be described with reference to a flowchart shown in FIG. 1.

[melting ‧ casting step: S01]

First, a molten copper alloy having the above composition is melted. As a copper raw material, 4NCu (oxygen-free copper, etc.) having a purity of 99.99 mass% or more is used. It is advisable, but waste can also be used as a raw material. Further, in the case of melting, an atmosphere furnace can be used. However, in order to suppress oxidation of the additive element, an atmosphere furnace using a vacuum furnace, an inert gas atmosphere, or a reductive atmosphere may be used.

Next, the composition-adjusted molten copper is cast by a suitable casting method using a vertical casting furnace or a horizontal casting furnace, such as a batch casting method such as die casting, a continuous casting method, a semi-continuous casting method, or the like. An ingot (for example, a plate-shaped ingot) is obtained after the alloy.

[heating step: S02]

Thereafter, a homogenization heat treatment is performed in order to homogenize the ingot structure in order to eliminate the segregation of the ingot. Further, in order to solidify the crystals and precipitates, a solution heat treatment is performed. The conditions of the heat treatment are not particularly limited, but they are usually heated at 600 ° C to 1000 ° C for 1 second to 24 hours. If the temperature is less than 600 ° C or the holding time is less than 5 minutes, there is a possibility that a sufficient homogenization effect or a solid solution effect cannot be obtained. On the other hand, if the temperature is maintained above 1000 ° C, a part of the segregation portion will be melted, and if the holding time exceeds 24 hours, the cost will increase. The cooling conditions after the heat treatment may be appropriately determined, but water quenching is usually employed. Further, after the heating step S02, the surface shaving is performed as needed.

[Heat processing step: S03]

Next, in order to improve the efficiency of the roughing and the homogenization of the structure, the ingot may be subjected to hot intercalation after the heating step S02 described above. The The conditions for the hot working are not particularly limited, but usually, the starting temperature is 600 ° C or more and 1000 ° C or less, the finishing temperature is 300 ° C or more and 850 ° C or less, and the working ratio is 10% or more and 99% or less. Further, the ingot heating to the hot start processing temperature may also serve as the heating step S02 described above. That is, after heating in the heating step S02, it is not cooled to near room temperature, and the hot inter-process may be started at the above-described inter-heat processing start temperature. The cooling conditions after the hot working can be appropriately determined, and water quenching is usually used. However, after the hot room is processed, the surface is cut as needed. The processing method of the hot intercalation processing is not particularly limited. However, when the final shape is a plate or a strip, the inter-heat rolling is applied, and it may be rolled to a thickness of about 0.5 mm or more and 50 mm or less. Further, if the final shape is a wire or a rod, extrusion or groove rolling is applied, and if the final shape is a block shape, forging or pressing may be applied. Further, in the ingot produced by the horizontal continuous casting method, the hot intercalation step is usually not performed.

[Intermediate plastic processing step: S04]

Next, the intermediate plastic working is performed on the ingot which is subjected to the homogenization treatment in the heating step S02 or the hot interleave processed material in the interheat processing step S03 in which the inter-heat rolling is performed. The temperature condition in the intermediate plastic working step S04 is not particularly limited, but it is preferably in the range of -200 ° C to +200 ° C which is cold or intertemporal processing. The processing rate of the intermediate plastic working is also not particularly limited, but is usually about 10% or more and 99% or less. The processing method is not particularly limited, but if the final shape is a plate or a strip (a shape that is wound into a coil shape), rolling is applied and rolled to 0.05 mm or more and 15 mm. The thickness of the bottom left and right can be. Further, if the final shape is a wire or a rod, extrusion or groove rolling may be applied, and if the final shape is a block shape, forging or pressing may be applied.

[Intermediate heat treatment step: S05]

Next, after the intermediate plastic working step S04, an intermediate heat treatment which also serves as a solution heat treatment is applied. By performing this intermediate heat treatment, fine [Ni,Fe]-P-based precipitates or [Ni,(Fe,Co)]-P-based precipitates are solid-solved in the matrix phase. Here, in the intermediate heat treatment, a batch type heating furnace or a continuous annealing treatment line may be used. When the intermediate heat treatment is carried out using a batch type heating furnace, it is preferably heated at a temperature of from 600 ° C to 1000 ° C for 5 minutes or more and 24 hours or less. In the case where the intermediate heat treatment is performed using the continuous annealing line, the heating reaching temperature is set to 650 ° C or more and 1000 ° C or less, and is not maintained or maintained for 1 second or more and 5 minutes or less at a temperature within the range. It is better. As described above, the heat treatment conditions in the intermediate heat treatment step S05 will differ depending on the specific means for performing the heat treatment.

Further, the atmosphere for the intermediate heat treatment is preferably a non-oxidizing atmosphere (a nitrogen atmosphere, an inert gas atmosphere, or a reductive atmosphere).

Although the cooling conditions after the intermediate heat treatment are not particularly limited, they may be usually cooled at a cooling rate of about 2,000 ° C / sec to 100 ° C / hr.

Further, in order to complete the solid solution, the intermediate plastic working step S04 and the intermediate heat treatment step S05 may be repeated.

[Final plastic processing step: S06]

After the intermediate heat treatment step S05, the final plastic working is performed until the final size and the final shape. The processing method in the final plastic working is not particularly limited, but if the final product form is a sheet or a strip, rolling (cold rolling) is applied, and the sheet thickness is rolled to a thickness of about 0.05 mm or more and 3.0 mm or less. Just fine. Others, for the final product form, can also be applied to forging or pressing, groove rolling and the like. The processing ratio may be appropriately selected depending on the final thickness or the final shape, but it is preferably in the range of 1% or more and 80% or less. When the processing ratio is less than 1%, the effect of improving the endurance cannot be sufficiently obtained. On the other hand, when it exceeds 80%, the recrystallized structure is substantially lost to become a processed structure, and the bending workability is lowered. Further, the processing ratio is preferably 5% or more and 80% or less, and more preferably 10% or more and 80% or less. After the final plastic working, the person can be directly used as a product, but it is usually preferred to carry out the final heat treatment.

[Final heat treatment step: S07]

After the final plastic working, the final heat treatment step S07 is performed in order to improve the stress relaxation resistance and the heat resistance and the low temperature annealing hardening, or to remove the residual strain. The final heat treatment is preferably carried out at a temperature in the range of from 250 ° C to 600 ° C for from 1 hour to 48 hours. When the heat treatment temperature is high, a short-time heat treatment is performed, and when the heat treatment temperature is low, a long-time heat treatment may be performed. If the temperature of the final heat treatment is less than 250 ° C, or the time of the final heat treatment is less than 1 hour, sufficient stress release cannot be obtained. Put the effect on it. On the other hand, if the temperature of the final heat treatment exceeds 600 ° C, there is a crystallization of recrystallization, and further, the time of the final heat treatment exceeds 48 hours, which only causes an increase in cost.

Further, in the present embodiment, the atomic ratio of the content of Fe in the [Ni, Fe]-P-based precipitate to the content of Ni is controlled by the temperature increase rate. The temperature increase rate is preferably 0.1 ° C / min or more and 10 ° C / min or less.

A Cu-Zn-Sn-based alloy material having a final product form can be obtained in the same manner as above. In particular, when rolling is applied as a processing method, a Cu-Zn-Sn-based alloy sheet (bar) having a thickness of about 0.05 mm or more and 3.0 mm or less can be obtained.

Such a thin plate can also be used directly for a conductive member for an electric/electrical device. However, Sn plating having a thickness of about 0.1 to 10 μm is usually applied to one or both sides of the surface of the board to be attached with Sn. A plated copper alloy strip and a conductive member for electronic and electrical equipment used for other terminals of connectors. The method of Sn plating in this case is not particularly limited. Further, depending on the case, it is also possible to apply a reflow treatment after electrolytic plating.

In the copper alloy for electric and electric equipment according to the present embodiment, the [Ni,Fe]-P-based precipitate from the mother phase of the α-phase main body is appropriately present, and [Ni, Fe] The atomic ratio [Fe/Ni] _P of the content of Fe in the P-precipitate to the content of Ni, and the atomic ratio [Fe/Ni] of the content of Fe to the content of Ni in the entire alloy is set to [Fe/Ni]. In the range of 5 or more and 200 or less, the stress relaxation resistance and the heat resistance are sufficiently excellent, and the strength (endurance) is also high.

Further, in the case where Fe and Co are added, the [Ni, (Fe, Co)]-P-based precipitate from the mother phase of the α-phase main body is appropriately present, and [Ni, (Fe, Co) The atomic ratio of the content of (Fe + Co) to the content of Ni in the P-precipitate [(Fe + Co) / Ni] _P , the content of (Fe + Co) with respect to the entire alloy and When the atomic ratio [(Fe + Co) / Ni] of the content of Ni is in the range of 5 or more and 200 or less, the stress relaxation resistance and the heat resistance are sufficiently excellent, and the strength (endurance) is also high.

The copper alloy sheet for an electric/electrical device of the present embodiment is formed of a rolled material of the above-mentioned copper alloy for electric and electric equipment, and therefore has excellent stress relaxation resistance and heat resistance, and can be suitably used for a connector or the like. Terminals, bus bars, movable conductive sheets of electromagnetic relays, lead frames, etc.

The conductive member and the terminal for the electronic/electrical device of the present embodiment are composed of the above-described copper alloy for electronic and electrical equipment, and a copper alloy sheet for electronic and electrical equipment. Therefore, the stress relaxation resistance and the heat resistance are excellent. It is difficult to generate stress relaxation in a high-temperature environment or in a high-temperature environment, and the reliability is excellent because the strength (hardness) at a high temperature is also reduced. Moreover, the thickness of the conductive member and the terminal for the electronic/electrical device can be reduced.

The embodiment of the present invention has been described above, but the present invention is not limited thereto, and can be appropriately modified without departing from the scope of the technical idea of the invention.

For example, an example of the production method may be mentioned, but the invention is not limited thereto. The copper alloy for electronic and electrical equipment finally obtained may satisfy the composition range specified by the present invention and the composition of the precipitate.

[Examples]

Hereinafter, the results of the verification experiment performed to confirm the effects of the present invention are shown as examples of the present invention, and are shown together with the comparative examples. The following examples are intended to illustrate the effects of the present invention, and the configurations, processes, and conditions described in the examples are not intended to limit the technical scope of the present invention.

First, a raw material made of Cu-40mass%Zn master alloy and oxygen-free copper (ASTM B152 C10100) having a purity of 99.99 mass% or more is prepared, and this is placed in a high-purity graphite crucible, and horizontally used in a N ₂ atmosphere. Continuous casting furnace to melt. Various addition elements were added to the molten copper alloy to melt the molten alloy of the component compositions shown in Tables 1 to 3, and a carbon mold was used to produce an ingot. Thereafter, the cutting was performed to a thickness of about 11 mm, a width of about 80 mm, and a length of about 200 mm.

Next, each of the cut ingots was subjected to heat treatment (homogenization treatment), and maintained at 800 ° C for 4 hours in an Ar atmosphere, followed by water quenching.

Thereafter, surface grinding is performed, and intermediate plastic working and intermediate heat treatment are performed. Specifically, the roughing is performed by making the longitudinal direction of the ingot into a rolling direction and performing cold rolling at a rolling ratio of 95%.

Thereafter, the intermediate heat treatment for the solution treatment is carried out at 700 ° C for a predetermined time so that the average crystal grain size after the intermediate heat treatment is about 20 μm, and water quenching is performed. Thereafter, the rolled material was cut, and surface grinding was performed to remove the oxide film.

Next, cold rolling was performed using a final plastic working at a rolling ratio of 50%. Thereafter, the temperature was raised to 350 ° C at the temperature increase rate shown in Tables 4 to 6, and the final heat treatment was performed for a predetermined period of time, followed by water quenching. Of course Thereafter, cutting and surface grinding were carried out to prepare a strip for property evaluation having a thickness of 0.25 mm and a width of about 180 mm.

For the evaluation of the properties, the mechanical properties (endurance) were investigated, and the stress relaxation resistance and heat resistance were investigated, and the microstructure was observed. The test methods and measurement methods for each evaluation item are as follows.

[crystal grain size observation]

The crystal grain size after the intermediate heat treatment (intermediate annealing) was measured as follows. The surface which is perpendicular to the width direction of the rolling, that is, the TD surface (Transverse direction) is used as the observation surface, and is mechanically polished using water-resistant abrasive paper or diamond abrasive grains, and then finally polished using a colloidal cerium oxide solution. After the polishing, etching was carried out using a mixture of sulfuric acid and nitric acid as an etching solution, and the metal structure was observed by an optical microscope. The crystal grain size is a cutting method according to JIS H 0501 (corresponding to ISO2624-1973), and five longitudinal and lateral designated line segments are drawn, and the number of completely cut crystal grains is counted, and the length is cut. The average value is taken as the average crystal grain size.

[observation of precipitates]

A perforated electron microscope (TEM: manufactured by Hitachi, H-800, HF-2200, and EDX analyzer (manufactured by Noran, EDX analyzer SYSTEM SIX) was used for each characteristic evaluation strip, and the precipitate observation was performed as follows. .

After mechanical polishing using water-resistant abrasive paper and diamond abrasive grains from the surface and the back surface of the rolled material, a TEM observation sample was produced by a double jet method using an electrolytic solution. The TEM observation sample was produced from two portions of the surface and the back surface of the rolled material in two portions of 1/4 length in the thickness direction.

When 10 or more precipitates having a particle diameter of about 10 nm to 50 nm were subjected to electron beam diffraction, it was confirmed that these precipitates have hexagonal crystals of a Fe ₂ P-based or Ni ₂ P-based crystal structure (space group: P- 62 m (189)) or Co ₂ P-based or Fe ₂ P-based orthorhombic (space group: P-nma (62)). After the electron beam was diffracted, and the composition of the precipitate was analyzed by EDX (energy dispersive X-ray spectroscopy) for each of the precipitates, it was confirmed that the precipitated product contained a group selected from the group consisting of Fe and Co and Ni. At least one of the elements and the P, that is, one of the defined [Ni, (Fe, Co)]-P system precipitates. Moreover, the Fe/Ni ratio or the (Fe+Co)/Ni ratio in the precipitate was calculated from the analysis result of the composition of the precipitate of EDX.

[Evaluation of heat resistance]

The heat resistance was evaluated in accordance with JCBA T315:2002 "Test for Annealing Softening Characteristics of Copper and Copper Alloy Strips" at a semi-softening temperature at the time of heat treatment at each temperature for one hour. The sum of the hardness of the strip for property evaluation and the hardness of the strip which was heat-treated at 700 ° C for 1 hour in an electric furnace was calculated, and the temperature at which the hardness was half with respect to the total was set as the "half-softening temperature". Plot the hardness after each hour at 50 ° C in a temperature range of 200 to 700 ° C, and prepare a hardness-temperature curve, thereby The "actual semi-softening temperature" is determined by the curve.

In addition, the hardness is based on the microhardness test method prescribed by JIS-Z2248 (ISO7438:2005, Metallic Materials-Bend test (MOD)), and the surface of the property evaluation strip, that is, the ND plane (Normal Direction) is aggravated by the test. 1.96 N (= 0.2 kgf) to determine Vickers hardness.

[mechanical characteristics]

The test piece No. 13B specified in JIS Z 2201 (corresponding to ISO6892) was extracted from the strip for property evaluation, and by JIS-Z 2241 (ISO6892-1:2009, Metallic Materials-Tensile testing-Part 1: Method of test at The room temperature (MOD)) offset method was used to determine the Young's modulus E and the 0.2% endurance σ _0.2 . Further, the test piece was subjected to a tensile test in a tensile direction and extracted in a direction perpendicular to the rolling direction of the property evaluation strip.

The Young's modulus E obtained was used for the stress relaxation resistance test.

[stress relaxation resistance]

The stress relaxation resistance test was performed by loading the stress according to the cantilever beam type method of the Japan Copper Association Technical Standard JCBA-T309:2004, for samples with a Zn amount exceeding 2 mass% and less than 15 mass% (recorded in Table 4). The "2-15Zn evaluation" column in ~6), the residual stress rate after holding at 150 ° C for 500 hours, the amount of Zn is A sample having a mass of 15 mass% or more and 36.5 mass% or less (recorded in the column of "15-36.5Zn evaluation" in Tables 4 to 6) was used to measure the residual stress rate after holding at a temperature of 120 ° C for 500 hours.

As a test method, a test piece (width: 10 mm) is extracted from each of the characteristics evaluation strips in a direction perpendicular to the rolling direction, and the maximum surface stress of the test piece is 80% of the endurance, and the initial bending is performed. The displacement is set to 2mm and the span length is adjusted. The above surface maximum stress can be defined by the formula.

Surface maximum stress (MPa) = 1.5Et δ ₀ /Ls ²

However, E: Young's coefficient (MPa)

t: thickness of the sample (t=0.25 mm)

δ ₀ : initial flexural displacement (2mm)

Ls: span length (mm).

Further, the residual stress rate was calculated using the following formula.

Residual stress rate (%) = (1 - δ t / δ ₀ ) × 100

However, δ t: permanent flexural displacement (mm) after holding at 120 ° C for 500 h, or after maintaining at 150 ° C for 500 h - permanent flexural displacement (mm) after being kept at normal temperature for 24 h

δ ₀ : initial flexural displacement (mm).

If the residual stress rate is 80% or more, the evaluation is ○, and less than 80% is evaluated. Estimated by ×.

The results of the evaluations described above are shown in Tables 4, 5, and 6.

In Comparative Example 101, the atomic ratio of the total content of Fe and Co in the [Ni, (Co, Fe)]-P-based precipitate to the content of Ni [(Fe + Co) / Ni] _P , and the alloy The ratio of the total atomic ratio of Fe and Co to the content of Ni ((Fe+Co)/Ni) [(Fe+Co)/Ni] _P /[(Fe+Co)/Ni] Since the range of the present invention is low, heat resistance and stress relaxation resistance are insufficient.

In Comparative Example 102, the atomic ratio [Fe/Ni] _P of the content of Fe in the [Ni,Fe]-P-based precipitate to the content of Ni, and the content of Fe in the entire alloy and the content of Ni in the alloy. Since the ratio of atomic ratio [Fe/Ni] [Fe/Ni] _P / [Fe/Ni] is higher than the range of the present invention, heat resistance and stress relaxation resistance are insufficient.

In Comparative Example 103, since the content of Fe was larger than the range of the present invention, heat resistance and stress relaxation resistance were insufficient.

In Comparative Example 104, since P and Fe were not added, heat resistance and stress relaxation resistance were insufficient.

In Comparative Example 105, since P was not added, heat resistance and stress relaxation resistance were insufficient.

In Comparative Example 106, the content of Ni was smaller than the range of the present invention, and the atomic ratio of (Ni + Fe) / P, Sn / (Ni + Fe) and Fe / Ni was also outside the scope of the present invention, so heat resistance And the stress relaxation resistance is insufficient.

In contrast, not only the individual content of each alloying element is set within the range defined by the present invention, but the ratio of each alloy component to each other is also within the range defined by the present invention, and further, [Ni, The atomic ratio [Fe/Ni] _P of the content of Fe in the Fe]-P-based precipitate to the content of Ni, and the atomic ratio of the content of Fe in the entire alloy to the content of Ni [Fe/Ni] The atomic ratio of the total content of Fe and Co in the [Fe/Ni] _P /[Fe/Ni] or [Ni,(Co,Fe)]-P-based precipitates to the content of Ni [(Fe+ Co)/Ni] _P , and the ratio of the total content of Fe and Co in the alloy to the atomic ratio of the content of Ni [(Fe + Co) / Ni] [(Fe + Co) / Ni] _P / [( Also, in the examples of the present invention in the range of the present invention, Fe+Co)/Ni] is excellent in heat resistance and stress relaxation resistance, and thus can be suitably applied to a connector or other terminal.

In the example No. 41 of the present invention shown in Table 2, although Sn/(Ni+Fe+Co) is expressed as 0.30, this value is 0.3003 for the coincidence with the decimal point of other values. . That is, Sn/(Ni+Fe+Co) of the inventive example No. 41 is within the scope of the invention.

Claims (5)

A copper alloy for electric and electrical equipment, characterized by containing more than 2 mass% and 36.5 mass% or less of Zn, 0.1 mass% or more and 0.9 mass% or less of Sn, 0.15 mass% or more, and less than 1.0 mass% of Ni, 0.005 mass% or more and 0.1 mass% or less of P, 0.001 mass% or more and 0.1 mass% or less of Fe, the remainder is made of Cu and unavoidable impurities; and the ratio of the total content of Ni and Fe to the content of P ( Ni+Fe)/P is in an atomic ratio of 3<(Ni+Fe)/P<30, and the ratio of the content of Sn to the total content of Ni and Fe is Sn/(Ni+Fe) in atomic ratio. In order to satisfy 0.3<Sn/(Ni+Fe)<2.7, the ratio of the content of Fe to the content of Ni [Fe/Ni] satisfies 0.002 ≦[Fe/Ni]<0.6 in atomic ratio; The mother phase has a [Ni,Fe]-P-based precipitate containing Fe, Ni and P, and an atomic ratio of the content of Fe in the Ni-Fe-P-based precipitate to the content of Ni [Fe/ Ni] _P , the atomic ratio [Fe/Ni] of the content of Fe to the content of Ni in the entire alloy satisfies 5 ≦ [Fe/Ni] _P / [Fe/Ni] ≦ 200. A copper alloy for electric and electrical equipment, characterized by containing more than 2 mass% and 36.5 mass% or less of Zn, 0.1 mass% or more and 0.9 mass% or less of Sn, 0.15 mass% or more, and less than 1.0 mass% of Ni, 0.005 mass% or more and 0.1 mass% or less of P together, and Fe and Co are contained, and the total content of Fe and Co is 0.001 mass% or more and 0.1 mass% or less (however, it is 0.001 mass% or more and 0.1 mass% or less). Fe), the remainder is made of Cu and unavoidable impurities; the ratio of the total content of Ni, Fe, and Co to the content of P (Ni+Fe+Co)/P is 3<(Ni) in atomic ratio. +Fe+Co)/P<30, and the ratio of the content of Sn to the total content of Ni, Fe, and Co is Sn/(Ni+Fe+Co) in an atomic ratio of 0.3<Sn/(Ni+Fe). +Co)<2.7, and the ratio of the total content of Fe and Co to the content of Ni (Fe+Co)/Ni satisfies 0.002≦(Fe+Co)/Ni<0.6 in atomic ratio; In the phase, there are at least one of Fe and Co, and [Ni, (Fe, Co)]-P-based precipitates of Ni and P, and Fe in the [Ni, (Fe, Co)]-P-based precipitate. And the atomic ratio of the total content of Co to the content of Ni [(Fe+Co)/Ni] _P , relative to the Fe of the alloy as a whole The atomic ratio [(Fe + Co) / Ni] of the total content of Co to the content of Ni satisfies 5 ≦ [(Fe + Co) / Ni] _P / [(Fe + Co) / Ni] ≦ 200. A copper alloy sheet for an electric/electrical machine, which is characterized by being a rolled material of a copper alloy for electric equipment and electric equipment of claim 1 or claim 2, and having a thickness of 0.05 mm or more and 3.0 mm or less. A conductive member for an electric/electrical machine, characterized by being made of a copper alloy sheet for electronic and electrical equipment of claim 3. A terminal characterized by the copper alloy sheet for electronic and electrical equipment of claim 3.