CN108291275B

CN108291275B - Copper alloy material

Info

Publication number: CN108291275B
Application number: CN201680065120.7A
Authority: CN
Inventors: 矢野翔一郎; 佐藤志信; 坂本敏夫
Original assignee: Mitsubishi Materials Corp
Current assignee: Mitsubishi Materials Corp
Priority date: 2015-11-09
Filing date: 2016-10-11
Publication date: 2020-03-13
Anticipated expiration: 2036-10-11
Also published as: KR20180078244A; EP3375897A1; WO2017081969A1; EP3375897B1; JP6736869B2; CN108291275A; US20180291490A1; KR102493118B1; EP3375897A4; JP2017088948A

Abstract

The invention is characterized by having the following composition: the Cr-Zr-P alloy material contains 0.1 to 1.5 mass% of Cr, 0.05 to 0.25 mass% of Zr, 0.005 to 0.10 mass% of P, and the balance of Cu and unavoidable impurities, and contains Cr, Zr and P, wherein the Cr-Zr-P compound has an area ratio of 0.5 to 5.0% in a structural observation, is in a needle-like or granular form, and has a longest side length of 100 [ mu ] m or less.

Description

Copper alloy material

Technical Field

The present invention relates to a copper alloy material suitable for parts used in a high-temperature environment, such as a casting die material and a welding part such as a contact piece.

This application claims priority based on 2015, 11/9/japanese patent application No. 2015-219851 and uses the contents therein.

Background

Conventionally, Cu — Cr — Zr alloys such as C18150 have been used as a material for a casting die and a welding member in a high temperature environment as shown in patent documents 1 to 3 because of their excellent heat resistance and electrical conductivity.

Such a Cu — Cr — Zr alloy is generally produced through the following production steps: a Cu-Cr-Zr alloy ingot is subjected to plastic working, for example, solution treatment for holding at 950 to 1050 ℃ for 0.5 to 1.5 hours and aging treatment for holding at 400 to 500 ℃ for 2 to 4 hours, and finally machined into a predetermined shape. The solution treatment step in the Cu — Cr — Zr-based alloy may be performed together with the plastic working step, or may be produced by replacing the so-called inline (inline) solution treatment in which the solution treatment is performed simultaneously with the hot rolling.

In addition, in the Cu — Cr — Zr alloy, Cr and Zr are solid-dissolved in a parent phase of Cu in a solid solution treatment, and precipitates of Cr and Zr are finely dispersed by an aging treatment, thereby improving strength and electric conductivity.

Patent document 1: japanese laid-open patent publication No. 62-182238 (A)

Patent document 2: japanese laid-open patent publication No. 62-182239 (A)

Patent document 3: japanese laid-open patent publication No. H04-210438 (A)

Although the Cu — Cr — Zr-based alloy has excellent heat resistance, when exposed to a use environment having a peak temperature of 500 ℃ or higher, re-solution of precipitates starts to occur, and as the re-solution proceeds, strength and conductivity decrease, and crystal grains coarsen.

When the crystal grains are coarsened, the propagation speed of cracks may increase, and the product life may be shortened. Further, since the crystal grains are locally coarsened, there is a problem that mechanical properties such as strength and elongation are remarkably reduced.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and an object thereof is to provide a copper alloy material which can suppress coarsening of crystal grains even when used in a high-temperature environment of 500 ℃ or higher, has stable performance, and has an excellent service life.

In order to solve the above problem, a copper alloy material according to an aspect of the present invention (hereinafter referred to as "copper alloy material of the present invention") has a composition comprising: the Cr-Zr-P alloy material contains 0.1 to 1.5 mass% of Cr, 0.05 to 0.25 mass% of Zr, 0.005 to 0.10 mass% of P, and the balance of Cu and unavoidable impurities, and contains Cr, Zr and P, wherein the Cr-Zr-P compound has an area ratio of 0.5 to 5.0% in a structural observation, is in a needle-like or granular form, and has a longest side length of 100 [ mu ] m or less.

The copper alloy material having this structure contains 0.1 to 1.5 mass% Cr, 0.05 to 0.25 mass% Zr, and 0.005 to 0.10 mass% P, with the remainder being Cu and unavoidable impurities, and thus, the strength (hardness) and the electrical conductivity can be improved by precipitating fine precipitates by aging treatment.

In the copper alloy material of the present invention, a Cr-Zr-P compound containing Cr, Zr, and P is present, and the area ratio of the Cr-Zr-P compound is set in the range of 0.5% to 5.0% in the structure observation. Since the Cr — Zr — P compound containing Cr, Zr, and P does not disappear even under high temperature conditions of about 1000 ℃, coarsening of crystal grains can be suppressed by pinning effect (pinning effect) of grain boundaries due to the Cr — Zr-P compound even when used in a high temperature environment.

Further, the Cr-Zr-P compound is in the form of a needle or a granule, and the longest side is set to be 100 μm or less, so that the pinning effect can be reliably exhibited.

In the copper alloy material of the present invention, it is preferable that the average crystal grain size after the heat treatment at 1000 ℃ for 30 minutes is 200 μm or less.

In this case, the crystal grains are not coarsened even after the heat treatment at 1000 ℃ for 30 minutes, and the mechanical properties and the electrical conductivity are stable even when the material is used in a high-temperature environment of 500 ℃ or higher.

In the copper alloy material of the present invention, it is preferable that Co is contained in a range of 0.02 mass% or more and 0.15 mass% or less, and the atomic ratio [ Co ]/[ P ] of Co to P is in a range of 0.5. ltoreq. Co ]/[ P ]. ltoreq.5.0.

In this case, since Co is contained in a range of 0.02 mass% or more and 0.15 mass% or less in addition to Cr and Zr, a CoP compound and Co are present₂The P compound can exhibit the pinning effect of the grain boundary together with the Cr-Zr-P compound, and can reliably suppress the coarsening of the crystal grains even when used in a high-temperature environment.

Further, the atomic ratio [ Co ] to P [ P ] is set to 0.5. ltoreq. Co ]/[ P ] is set to 5.0 or less, so that it is possible to suppress the remaining Co and P from being dissolved in the matrix phase and to suppress the decrease in conductivity.

Further, in the copper alloy material of the present invention containing Co, the total content of Ti and Hf as inevitable impurities is preferably 0.10 mass% or less.

In this case, since the total content of Ti and Hf as elements forming a compound with P is limited to 0.10 mass% or less, a CoP compound and Co can be reliably formed₂The P compound can effectively exhibit pinning effect of grain boundaries and can suppress coarsening of crystal grains.

According to the present invention, it is possible to provide a copper alloy material which can suppress coarsening of crystal grains even when used in a high-temperature environment of 500 ℃ or higher, has stable performance, and has an excellent service life.

Drawings

Fig. 1 is a flowchart of a method for producing a copper alloy material according to an embodiment of the present invention.

Fig. 2A is a photograph of a tissue observation of the example. A photograph showing the structure of example 2 of the present invention.

Fig. 2B is a photograph of the tissue observation of the example. The photograph of the structure of comparative example 1 is shown.

FIG. 3A is a photograph showing the structure after heat treatment at 1000 ℃ for 30 minutes. The structure observation photograph after the heat treatment of example 2 of the present invention is shown.

FIG. 3B is a photograph showing the structure after heat treatment at 1000 ℃ for 30 minutes. The structure observation photograph after the heat treatment of comparative example 1 is shown.

FIG. 4A is an SEM image of example 2 of the present invention.

FIG. 4B shows an EPMA (Cr) image of example 2 of the present invention.

FIG. 4C is an EPMA (Zr) image of example 2 of the present invention.

Fig. 4D is an epma (p) image of comparative example 2.

Fig. 5A is an SEM image of comparative example 1.

FIG. 5B is an EPMA (Cr) image of comparative example 1.

FIG. 5C is an EPMA (Zr) image of comparative example 1.

FIG. 6 shows an example of SEM-EPMA image when the area ratio of the Cu-Zr-P compound is calculated.

Detailed Description

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

The copper alloy material of the present embodiment is used for parts used in a high-temperature environment, such as a casting die and a welding part.

The copper alloy material of the present embodiment has the following composition: contains 0.1 to 1.5 mass% of Cr, 0.05 to 0.25 mass% of Zr, 0.005 to 0.10 mass% of P, and the balance of Cu and unavoidable impurities.

In addition, the copper alloy material of the present embodiment may contain Co in the range of 0.02 mass% or more and 0.15 mass% or less as necessary, and the atomic ratio [ Co ]/[ P ] of Co to P may be in the range of 0.5. ltoreq. Co ]/[ P ] ≦ 5.0. When Co is contained, the total content of Ti and Hf as inevitable impurities is preferably 0.10 mass% or less.

In the copper alloy material of the present embodiment, a Cr — Zr — P compound (phase) containing Cr, Zr, and P is present, and the area ratio of the Cr — Zr — P compound (phase) is in the range of 0.5% to 5.0% in the structure observation of any cross section. The Cr-Zr-P compound is in the form of a needle or a granule, and the longest side is 100 μm or less.

The "Cr-Zr-P compound phase" means a phase composed of a Cr-Zr-P compound in a predetermined content and surrounded by grain boundaries.

The needle-like morphology means that the aspect ratio of the phase is 5 or more, and the granular morphology means that the aspect ratio of the phase is 1 to 3.

The length of the longest side of the needle-like form of the Cr-Zr-P compound (phase) is obtained by measuring the length in the longitudinal direction of the needle-like form.

The length of the longest side of the granular form of the Cr-Zr-P compound (phase) is obtained by measuring the length of the granular form in the direction in which the longest length can be obtained.

Regarding the area ratio of the Cr-Zr-P compound (phase), the area ratio of the Cr-Zr-P compound (phase) is obtained by microetching an arbitrary cross section (for example, a cross section parallel to the rolling direction) of the copper alloy material, observing the structure by SEM or the like, and further, performing elemental analysis on the cross section to be observed by EPMA or the like.

In the copper alloy material of the present embodiment, the average crystal grain size after the heat treatment at 1000 ℃ for 30 minutes is 200 μm or less.

The reason why the composition, crystal structure, and the like are defined as described above in the copper alloy material of the present embodiment will be described below.

(Cr is 0.1 mass% or more and 1.5 mass% or less)

Cr is an element having the following effects: that is, Cr-based precipitates are finely precipitated in grains of the matrix by aging treatment, thereby improving strength (hardness) and electric conductivity.

When the content of Cr is less than 0.1 mass%, the precipitation amount during the aging treatment may be insufficient, and the effect of improving the strength (hardness) may not be sufficiently obtained. When the content of Cr exceeds 1.5 mass%, coarse Cr crystal substances may be formed, and workability may be deteriorated.

From the above, in the present embodiment, the content of Cr is set within a range of 0.1 mass% or more and 1.5 mass% or less. In order to reliably achieve the above-described operational effects, the lower limit of the content of Cr is preferably 0.3 mass%, and the upper limit of the content of Cr is preferably 1.0 mass%.

(Zr: 0.05 to 0.25 mass%)

Zr is an element with the following function and effect: that is, Zr-based precipitates are finely precipitated in grains of the matrix by aging treatment, thereby improving strength (hardness) and electric conductivity.

If the Zr content is less than 0.05 mass%, the precipitation amount during the aging treatment may be insufficient, and the effect of improving the strength (hardness) may not be sufficiently obtained. When the Zr content exceeds 0.25 mass%, the electrical conductivity and the thermal conductivity may decrease. Further, even when more than 0.25 mass% of Zr is contained, there is a possibility that further strength improvement effect cannot be obtained.

From the above, in the present embodiment, the content of Zr is set to be in the range of 0.05 mass% or more and 0.25 mass% or less. In order to reliably achieve the above-described operational effects, the lower limit of the Zr content is preferably 0.07 mass%, and the upper limit of the Zr content is preferably 0.15 mass%.

(P is 0.005 to 0.10 mass%)

A Cr-Zr-P compound (phase) containing Cr, Zr and P is formed by adding P to a Cu-Cr-Zr alloy. Since the Cr-Zr-P compound (phase) does not disappear even under high temperature conditions such as 1000 ℃, the pinning effect of grain boundaries is exhibited even when the Cr-Zr-P compound is used under a high temperature environment, and coarsening of crystals can be suppressed.

When the content of P is less than 0.005% by mass, the Cr-Zr-P compound (phase) may not be sufficiently formed. On the other hand, when the content of P exceeds 0.10 mass%, the conductivity is lowered, and the Cr-Zr-P compound (phase) is coarsened, so that the pinning effect may not be sufficiently exhibited.

From the above, in the present embodiment, the content of P is set in the range of 0.005 mass% or more and 0.10 mass% or less. In order to reliably exhibit the above-described effects, the lower limit of the content of P is preferably 0.01 mass%, and the upper limit of the content of P is preferably 0.05 mass%.

(Co: 0.02 mass% or more and 0.15 mass% or less)

Formation of CoP compound and Co by Co addition₂P compound, CoP compound and Co₂The P compound and the Cr-Zr-P compound (phase) exhibit a pinning effect of grain boundaries, and even when used in a high-temperature environment, coarsening of crystal grains can be reliably suppressed.

When the Co content is less than 0.02 mass%, the CoP compound and Co cannot be sufficiently formed₂The P compound, despite the addition of Co, may not achieve a further improvement in pinning effect. On the other hand, when the content of Co exceeds 0.15 mass%, the CoP compound and Co₂The P compound is coarsened, and further improvement of the pinning effect may not be achieved even with the addition of Co.

From the above, when Co is added in the present embodiment, the content of Co is set in the range of 0.02 mass% or more and 0.15 mass% or less. In order to reliably exhibit the above-described effects, the lower limit of the content of Co is preferably 0.03 mass%, and the upper limit of the content of Co is preferably 0.1 mass%. Also, in the case where Co is not intentionally added, Co may be contained as an impurity in an amount of less than 0.02 mass%.

(atomic ratio of Co to P [ Co ]/[ P ]: 0.5 or more and 5.0 or less)

When Co is added, the atomic ratio [ Co ]/[ P ] of Co to P is set to be in the range of 0.5. ltoreq. Co ]/[ P ] ≦ 5.0. By defining the atomic ratio of Co to P [ Co ]/[ P ], formation of a CoP compound and Co can be suppressed₂The remaining Co and P that the P compound does not contribute to are dissolved in the mother phase, and the conductivity is lowered. In order to reliably exhibit the above-described effects, the lower limit of the atomic ratio [ Co ]/[ P ] of Co to P is preferably 1.0, and the upper limit of the atomic ratio [ Co ]/[ P ] of Co to P is preferably 3.0.

(total of Ti and Hf: 0.10% by mass or less)

When Co is added, the total content of Ti and Hf as inevitable impurities is preferably 0.10 mass% or less. These Ti and Hf elements are easily generatedA compound forming Co, and thus there is a possibility that the CoP compound and Co cannot be formed sufficiently₂And (3) a P compound. Therefore, by defining the total content of Ti and Hf as inevitable impurities as described above, the CoP compound and Co can be reliably formed₂P compound and can exert a pinning effect. In order to reliably exhibit the above-described effects, the total content of Ti and Hf as inevitable impurities is preferably 0.03 mass% or less.

(other unavoidable impurities: 0.05% by mass or less)

In addition to the above Cr, Zr, P, Co, Ti, Hf, other unavoidable impurities include B, Al, Fe, Sn, Zn, Si, Mg, Ag, Ca, Te, Mn, Ni, Sr, Ba, Sc, Y, V, Nb, Ta, Mo, W, Re, Ru, Os, Se, Rh, Ir, Pd, Pt, Au, Cd, Ga, In, Li, Ge, As, Sb, Tl, Pb, Be, N, H, Hg, Tc, Na, K, Rb, Cs, Po, Bi, lanthanides, O, S, C, and the like. These inevitable impurities may lower the electric conductivity and the thermal conductivity, and therefore the total amount is preferably 0.05 mass% or less.

(area ratio of Cr-Zr-P compound (phase): 0.5% or more and 5.0% or less)

When the area ratio of the Cr-Zr-P compound (phase) is less than 0.5%, the pinning effect of the grain boundary by the Cr-Zr-P compound (phase) may be insufficient, and the coarsening of the crystal grains may not be suppressed. On the other hand, if the area ratio of the Cr-Zr-P compound (phase) exceeds 5.0%, there is a possibility that the workability may be deteriorated.

From the above, in the present embodiment, the area ratio of the Cr — Zr — P compound (phase) is defined to be 0.5% or more and 5.0% or less. The lower limit of the area ratio of the Cr-Zr-P compound (phase) is preferably set to 1.0%, and the upper limit of the area ratio of the Cr-Zr-P compound (phase) is preferably set to 3.0%.

(the longest side of the needle-like, granular Cr-Zr-P Compound (phase) has a length of 100 μm or less.)

When the longest side of the needle-like or granular form of the Cr-Zr-P compound (phase) exceeds 100. mu.m, the pinning effect may not be sufficiently exhibited.

As described above, in the present embodiment, the length of the longest side of the Cr-Zr-P compound (phase) is defined to be 100 μm or less. The upper limit of the length of the longest side of the Cr-Zr-P compound (phase) is preferably 80 μm.

(average grain size after heat treatment at 1000 ℃ for 30 minutes: 200 μm or less)

The average crystal grain size after heat treatment at 1000 ℃ for 30 minutes is 200 μm or less, whereby, for example, coarsening of crystal grains is reliably suppressed when used in a high-temperature environment of 500 ℃ or more, and the properties such as strength are stabilized.

From the above, in the present embodiment, the average crystal grain size after the heat treatment at 1000 ℃ for 30 minutes is set to 200 μm or less.

Next, a method for producing a copper alloy material according to an embodiment of the present invention will be described with reference to a flowchart of fig. 1.

(melting and casting step S01)

First, a copper raw material made of oxygen-free copper having a copper purity of 99.99 mass% or more is charged into a carbon crucible, and melted in a vacuum melting furnace to obtain a copper melt. Next, the additive elements are added to the obtained melt so as to have a predetermined concentration, and a copper alloy melt is obtained by adjusting the composition.

Here, as the raw materials of Cr, Zr, and P as the additive elements, high-purity raw materials are used, and for example, a raw material of Cr having a purity of 99.99 mass% or more, a raw material of Zr having a purity of 99.95 mass% or more, and a raw material of P having a purity of 99.99 mass% or more are used. And Co was added as needed. As the raw materials of Cr, Zr, Co, and P, a master alloy with Cu can be used.

Then, the copper alloy melt adjusted in composition is poured into a mold to obtain an ingot.

(homogenization Process S02)

Subsequently, heat treatment is performed to homogenize the obtained ingot.

Specifically, the ingot is homogenized under the conditions of 950 ℃ to 1050 ℃ for 1 hour or more in the air atmosphere.

(Hot working Process S03)

Then, the ingot is hot-rolled at a reduction ratio of 50% to 99% in a temperature range of 900 ℃ to 1000 ℃ to obtain a rolled material. The hot working may be hot forging. Immediately after the hot working, cooling was performed by water cooling.

(solution treatment step S04)

Next, the rolled material obtained in the hot working step S03 is subjected to a heating treatment at 920 to 1050 ℃ and 0.5 to 5 hours, and then subjected to a solution treatment. The heat treatment is performed, for example, in the atmosphere or in an inert gas atmosphere, and cooling after heating is performed by water cooling.

Further, by performing the streamline solution treatment, the hot working step S03 and the solution treatment step S04 can be performed at the same time.

Specifically, the ingot is hot-rolled at a reduction ratio of 50% to 99% in a temperature range of 900 ℃ to 1000 ℃ inclusive, and immediately cooled from a temperature of 920 ℃ to 1050 ℃ inclusive by water cooling, thereby being subjected to solution treatment.

(aging treatment Process S05)

Next, after the solution treatment step S04, an aging treatment is performed to precipitate precipitates such as Cr-based precipitates and Zr-based precipitates in a fine manner, thereby obtaining an aging-treated material.

Here, the aging treatment is performed, for example, under conditions of 400 ℃ to 530 ℃ and 0.5 hour to 5 hours.

The heat treatment method in the aging treatment is not particularly limited, but is preferably performed in an inert gas atmosphere. The cooling method after the heat treatment is not particularly limited, but is preferably performed by water cooling.

The copper alloy material of the present embodiment is manufactured through such a process.

According to the copper alloy material according to the present embodiment configured as described above, since the composition contains 0.1 mass% to 1.5 mass% of Cr, 0.05 mass% to 0.25 mass% of Zr, 0.005 mass% to 0.10 mass% of P, and the balance of Cu and unavoidable impurities, fine precipitates are precipitated by the aging treatment, and the strength (hardness) and the electrical conductivity can be improved.

In addition, in the present embodiment, since the Cr — Zr — P compound (phase) containing Cr, Zr, and P is present, and the area ratio of the Cr — Zr — P compound (phase) is in the range of 0.5% or more and 5.0% or less in the structure observation, the Cr — Zr — P compound (phase) does not disappear even when used in a high-temperature environment, and coarsening of crystal grains can be suppressed by the pinning effect of the Cr — Zr — P compound (phase).

In the present embodiment, the Cr — Zr — P compound (phase) is in a needle-like or granular form, and the longest side is 100 μm or less, so that the pinning effect can be reliably exhibited.

In addition, in the present embodiment, since the average crystal grain size after the heat treatment at 1000 ℃ for 30 minutes is set to 200 μm or less, the crystal grains are not coarsened and the mechanical properties and the electrical conductivity are stable even when used in a high-temperature environment of 500 ℃ or more.

In the present embodiment, when Co is contained in a range of 0.02 mass% to 0.15 mass%, and the atomic ratio [ Co ]/[ P ] of Co to P is set in a range of 0.5. ltoreq. Co ]/[ P ] ≦ 5.0, a CoP compound and Co are formed₂The P compound can exhibit the pinning effect of the grain boundary together with the Cr — Zr — P compound (phase), and can reliably suppress coarsening of crystal grains even when used in a high-temperature environment. Further, the atomic ratio [ Co ] to P [ P ] is set to 0.5. ltoreq. Co ]/[ P ] is set to 5.0 or less, so that it is possible to suppress the remaining Co and P from being dissolved in the matrix phase and to suppress the decrease in conductivity.

When Co is contained, the total content of Ti and Hf, which are inevitable impurities, is 0.10 mass% or less, and thus the CoP compound and Co can be reliably formed₂P compound ofThe pinning effect of the grain boundary is effectively exerted, and coarsening of the crystal grains can be effectively suppressed.

The embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and can be modified as appropriate within a range not departing from the technical spirit of the present invention.

Examples

The results of the confirmation experiment performed to confirm the effects of the present invention will be described below.

A copper raw material comprising oxygen-free copper having a purity of 99.99 mass% or more was prepared, and the raw material was charged into a carbon crucible and then subjected to a vacuum melting furnace (degree of vacuum 10)^-2Pa or less) to obtain a molten copper. The obtained copper melt was added with various additive elements to adjust the composition shown in table 1, and after holding for 5 minutes, the copper alloy melt was poured into a cast iron mold to obtain an ingot. The ingot was about 80mm in width, about 50mm in thickness and about 130mm in length.

As the raw material of Cr as the additive element, a raw material having a purity of 99.99 mass% or more was used, and as the raw material of Zr, a raw material having a purity of 99.95 mass% or more was used.

Subsequently, the steel sheet was homogenized at 1000 ℃ for 1 hour in an atmospheric atmosphere, and then hot rolled. A hot rolled material having a width of about 100mm, a thickness of about 10mm and a length of about 520mm was obtained by setting the rolling reduction at the time of hot rolling to 80%.

In the present example, the solution treatment was performed by cooling at the cooling rate shown in table 1 at the end of hot rolling, and the so-called streamlined solution treatment was performed.

Next, aging treatment was performed at 500 (+ -15) ℃ for 3 hours. Thereby, a copper alloy material was obtained.

The structure of the copper alloy material after aging treatment of the obtained copper alloy material was observed, and the Cr-Zr-P compound (phase) was evaluated. The electrical conductivity and tensile strength of the copper alloy material after aging treatment were measured.

The heat treatment was performed by holding the copper alloy material after the aging treatment at 1000 ℃ for 30 minutes, and then water cooling was performed, and the average crystal grain size and tensile strength of the copper alloy material obtained were evaluated.

FIGS. 2A and 2B are photographs showing the structure of the copper alloy materials of example 2 of the present invention and comparative example 1, respectively, after the aging treatment and before the heat treatment at 1000 ℃ for 30 minutes.

Similarly, fig. 3A and 3B show photographs of the structure of the copper alloy materials of example 2 of the present invention and comparative example 1 after the aging treatment and the heat treatment at 1000 ℃ for 30 minutes, respectively.

(composition analysis)

The composition of the copper alloy material obtained was measured by ICP-MS analysis. The measurement results are shown in table 1.

(Cr-Zr-P Compound (phase))

In the thickness of the obtained copper alloy material, a sample of 10mm × 15mm was cut from the center of the width of the plate, and the surface in the rolling direction (RD direction) was polished and then microetched.

This sample was observed by SEM, and in an SEM-EPMA image (field of view of 250. mu. m.times.250. mu.m), a region having a higher Cr, Zr and P concentration than the parent phase was judged as "Cr-Zr-P compound (phase)", and the length of the longest side was measured. Then, the area ratio of the Cu-Zr-P compound was determined by the following formula.

Area ratio (area occupied by Cr-Zr-P compound (phase)/(250 μm × 250 μm)

Fig. 4A to 4D show SEM-EPMA images of inventive example 2, and fig. 5A to 5C show SEM-EPMA images of comparative example 1. FIG. 6 shows an example of SEM-EPMA image (field of view of 250. mu. m.times.250. mu.m) when calculating the area ratio of the Cu-Zr-P compound.

(average grain size)

In the thickness of the copper alloy material, a sample of 10mm × 15mm was cut from the center of the width of the plate, and the surface in the rolling direction (RD direction) was polished and then microetched.

The sample was observed, and the average crystal grain size was measured by the cutting method specified in JIS H0501.

(conductivity)

The center of the cross section of the 10mm × 15mm sample was measured 3 times using SIGMA TEST D2.068.068 (probe diameter φ 6mm) manufactured by FOERSTER JAPAN LIMITED.

(tensile Strength)

The test was carried out using a test piece of JIS Z22412 with the rolling direction set as the tensile direction and a 100kN tensile tester.

[ Table 1]

[ Table 2]

As shown in fig. 2A and 3A, in inventive examples 1 to 6, the coarsening of crystal grains was also suppressed after exposure to a high-temperature environment.

On the other hand, as represented in fig. 2B and 3B, in comparative examples 1 to 3 and 5, the crystal grains were coarsened after being left in a high-temperature environment. In comparative example 4, no coarsening of crystal grains was observed, but the conductivity was lowered as compared with examples 1 to 6 of the present invention (described later).

In comparative example 1 in which no P was added, a needle-like and granular Cr-Zr-P compound (phase) was not formed, and therefore, the tensile strength was greatly reduced after the heat treatment at 1000 ℃ for 30 minutes.

In comparative example 2 in which the area ratio of the needle-shaped and granular Cr-Zr-P compound (phase) exceeded the range of the present invention, the tensile strength was greatly reduced after the heat treatment at 1000 ℃ for 30 minutes.

In comparative example 3 in which the Zr content exceeded the range of the present invention, the electric conductivity was low, and the tensile strength was greatly reduced after the heat treatment at 1000 ℃ for 30 minutes.

In comparative example 4 in which the content of Co exceeds the range of the present invention, the conductivity is lowered.

In comparative example 5 in which the area ratio of the needle-like and granular Cr-Zr-P compound (phase) is smaller than the range of the present invention, the tensile strength was greatly reduced after the heat treatment at 1000 ℃ for 30 minutes.

On the other hand, in inventive examples 1 to 6, the electrical conductivity was high, and the tensile strength was not greatly reduced after the heat treatment at 1000 ℃ for 30 minutes. In inventive examples 3 to 6 in which the grain size after the heat treatment at 1000 ℃ for 30 minutes was 200 μm or less, the decrease in tensile strength after the heat treatment at 1000 ℃ for 30 minutes was further suppressed.

As is clear from the above, according to the examples of the present invention, it is possible to provide a copper alloy material which can suppress coarsening of crystal grains even when used in a high-temperature environment of 500 ℃.

Industrial applicability

The deterioration of properties of a member made of a Cu-Cr-Zr alloy in a high-temperature environment can be suppressed, and the life of products such as a die material for casting and a welding member can be extended.

Claims

1. A copper alloy material is characterized in that,

has the following composition: contains 0.1 to 1.5 mass% of Cr, 0.05 to 0.25 mass% of Zr, 0.005 to 0.10 mass% of P, and the balance of Cu and unavoidable impurities,

the copper alloy material further contains Co in a range of 0.02 mass% or more and 0.15 mass% or less, and the mass ratio [ Co ]/[ P ] of Co to P is set in a range of 0.5. ltoreq. Co ]/[ P ] ≦ 5.0,

wherein a Cr-Zr-P compound containing Cr, Zr and P is present in the copper alloy material, and the area ratio of the Cr-Zr-P compound is set to be in the range of 0.5% to 5.0% in the structure observation,

the Cr-Zr-P compound is in the form of a needle or a granule, and the longest side is 100 μm or less.

2. The copper alloy material according to claim 1,

the average grain size after heat treatment at 1000 ℃ for 30 minutes is 200 μm or less.

3. The copper alloy material according to claim 1 or 2,

the total content of Ti and Hf as inevitable impurities is set to 0.10 mass% or less.