A copper alloy, a method for preparing the same, and an application thereof

Abstract

The application belongs to the technical field of alloys, and particularly relates to a copper alloy and a preparation method and application thereof. The copper alloy comprises Cu and Ti3O4, and the mass fraction of Ti3O4 accounts for less than 8% of the copper alloy. The copper alloy of the application has a conductivity of more than 30% IACS due to the specific components and the special limitation of the content of Ti3O4, and the copper alloy of the application also has good compressive strength and elongation.

Description

Technical Field

[0001] This invention belongs to the field of alloy technology, and specifically relates to a copper alloy, its preparation method, and its application. Background Technology

[0002] Cu-Be alloys possess high hardness, elastic limit, fatigue limit, and wear resistance, as well as good corrosion resistance, thermal conductivity, and electrical conductivity, making them the preferred material for various conductive elastic components. However, due to the high toxicity of Be, the development of alternative materials for Cu-Be alloys is particularly important considering environmental protection and sustainable development factors. Among them, Cu-Ti alloys are an ideal alternative to Cu-Be alloys due to their high strength, high elasticity, good stress relaxation resistance, and good electrical conductivity. However, because electron scattering of Ti atoms has a significant impact on conductivity, solution-treated Ti significantly reduces the conductivity of Cu-Ti alloys, limiting their further application. To improve the conductivity of Cu-Ti alloys, Chinese invention patent 2020109742214 provides a Cu-Ti alloy with an ultrafine-grained structure exhibiting a conductivity of 18.89% IACS and a yield strength of 1076 MPa, along with its preparation method. Chinese invention patent 2018104605124 provides a method for preparing a Cu-Ti alloy strengthened by nano-oxide dispersion through cold pressing and hot pressing sintering to improve conductivity. However, these methods offer limited improvement in the conductivity of Cu-Ti alloys. Therefore, new preparation methods are still needed to further enhance the conductivity of Cu-Ti alloys.

[0003] In addition, although existing technologies use laser selective melting additive manufacturing to prepare Cu-Ti copper alloys, the Cu content in these copper alloys does not exceed 10%, with the balance being Ti. These copper alloys have good tensile strength and elongation, but their electrical conductivity is far below 30% IACS.

[0004] Therefore, there is an urgent need to provide a new copper alloy that significantly improves its electrical conductivity and, further, enhances its tensile strength and elongation. Summary of the Invention

[0005] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a copper alloy, its preparation method, and its applications. The copper alloy of this invention is Cu-Ti3O4, which has good electrical conductivity exceeding 30% IACS, for example, a conductivity of 31.8-56.5% IACS. Furthermore, the copper alloy of this invention also has good tensile strength and elongation.

[0006] A first aspect of the present invention is to provide a copper alloy.

[0007] A second aspect of the present invention is to provide a method for preparing the above-mentioned copper alloy.

[0008] A third aspect of the present invention is to provide applications of the aforementioned copper alloy.

[0009] Specifically, a copper alloy comprises Cu and Ti3O4; and the mass fraction of Ti3O4 accounts for less than 8% of the copper alloy.

[0010] Preferably, the copper alloy contains 0.1-7.5% Ti3O4 by mass fraction; more preferably, the Ti3O4 content is 0.1-5%. For example, the Ti3O4 content is 1-4% or 1.5-3.5%.

[0011] Preferably, in the copper alloy, Ti3O4 accounts for 0.1-5% by mass fraction, and the balance is Cu.

[0012] Preferably, the copper alloy has a conductivity exceeding 30% IACS; more preferably, the copper alloy has a conductivity exceeding 40% IACS; and even more preferably, the copper alloy has a conductivity exceeding 50% IACS. For example, the conductivity is 31.8-56.5% IACS.

[0013] Preferably, the compressive strength of the copper alloy is not less than 800 MPa; more preferably, the compressive strength of the copper alloy is not less than 1000 MPa; even more preferably, the compressive strength of the copper alloy is not less than 1300 MPa. For example, the compressive strength of the copper alloy is 800-1400 MPa.

[0014] Preferably, the elongation of the copper alloy exceeds 10%; more preferably, the elongation of the copper alloy exceeds 20%; even more preferably, the elongation of the copper alloy exceeds 30%. For example, the elongation of the copper alloy is 10-35%.

[0015] The preparation method of the above-mentioned copper alloy includes the following steps:

[0016] (1) Alloy powder mixing: Cu powder and Ti3O4 powder are mixed to obtain a mixed powder, and then the mixed powder is spread on the surface of the substrate;

[0017] (2) Selective laser melting: The mixed powder laid on the substrate surface in step (1) is selectively melted by laser, and then another layer of the mixed powder is laid, and then selective laser melting is performed again. The process of laying mixed powder and selective laser melting is repeated until the alloy of the target thickness is obtained.

[0018] (3) Deformation treatment: The alloy obtained in step (2) is subjected to warm rolling and cold rolling to obtain the copper alloy.

[0019] Preferably, in step (1), the particle size of the copper powder is 0.2-320 micrometers, more preferably 1-300 micrometers, more preferably 10-200 micrometers, and most preferably 50-150 micrometers.

[0020] Preferably, in step (1), the particle size of the Ti3O4 powder is 0.1-220 micrometers, more preferably 1-200 micrometers, more preferably 1-80 micrometers, and most preferably 10-50 micrometers.

[0021] Preferably, in step (1), the thickness of the mixed powder formed by spreading the mixed powder on the substrate surface is 0.01-0.5 mm, more preferably 0.05-0.15 mm, and even more preferably 0.05-0.1 mm.

[0022] Preferably, in step (2), when performing laser selective melting, the laser power is 200-600W, the scanning speed is 500-1000mm / s, and the scanning interval is 0.03-0.09mm.

[0023] More preferably, the laser power is 250-500W, and more preferably, the laser power is 300-400W.

[0024] More preferably, the scanning speed is 500-800 mm / s, and more preferably, the scanning speed is 500-600 mm / s.

[0025] More preferably, the scanning interval is 0.03-0.06 mm, and more preferably, the scanning interval is 0.03-0.05 mm.

[0026] Preferably, in step (2), the thickness of the alloy with the target thickness is 0.1-15 mm, more preferably 0.1-10 mm, more preferably 0.5-5 mm, and most preferably 1-3 mm.

[0027] Preferably, in step (3), the temperature of the warm rolling treatment is 400-500℃, more preferably 450-500℃.

[0028] Preferably, in step (3), the cold rolling process is a cold rolling process with a reduction of 50-90% per pass, and more preferably a cold rolling process with a reduction of 60-80% per pass.

[0029] The copper alloy obtained in step (2) is a plate, and the copper alloy obtained in step (3) is a copper alloy foil.

[0030] Selective laser melting additive manufacturing is a manufacturing technology that uses a laser as a heat source to rapidly heat, melt, and cool metal powder according to the three-dimensional data of the part, directly forming the raw material into a solid. Due to the rapid cooling characteristic, phase separation can be suppressed during the solidification process of the molten pool, improving the uniformity of the microstructure and obtaining ultrafine grains or amorphous materials.

[0031] A conductive element comprising the aforementioned copper alloy.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] (1) The copper alloy of the present invention contains specific components (i.e., Cu and Ti3O4), and the content of Ti3O4 is specifically limited. Therefore, the copper alloy has significantly improved conductivity, exceeding 30% IACS. Furthermore, the copper alloy of the present invention also has good compressive strength and elongation.

[0034] (2) Compared with existing technologies, the copper alloy preparation method of the present invention fully utilizes laser selective melting to obtain nano-fine grains, and simultaneously combines warm rolling treatment to further enhance precipitation strengthening through the interaction between dislocations and precipitated phases, thereby improving the strength of the copper alloy. At the same time, it purifies the copper alloy matrix, reduces the solid solubility of Ti in Cu, and improves conductivity, providing a simple and easy solution for obtaining copper-based alloys with high conductivity, high strength, and high elasticity. The Cu-Ti3O4 copper alloy foil prepared by the method of the present invention achieves a reasonable balance of strength, conductivity, and plasticity, and has a simple processing technology, low production cost, and wide application range. Detailed Implementation

[0035] To enable those skilled in the art to more clearly understand the technical solutions described in this invention, the following embodiments are provided for illustration. It should be noted that the following embodiments do not constitute a limitation on the scope of protection claimed by this invention.

[0036] Unless otherwise specified, the raw materials, reagents or devices used in the following examples are available from conventional commercial sources or can be obtained by existing known methods.

[0037] Example 1: Preparation of copper alloys

[0038] A copper alloy, by mass fraction, comprises 0.1% Ti3O4 and the balance is Cu.

[0039] The preparation method of the above-mentioned copper alloy includes the following steps:

[0040] (1) Alloy powder mixing: Weigh and mix Cu powder and Ti3O4 powder (the particle size of copper powder is 0.2 micrometers and the particle size of Ti3O4 powder is 100 micrometers) to obtain mixed powder. Then spread the mixed powder evenly on the surface of stainless steel substrate. The thickness of the mixed powder formed on the substrate surface is 0.02 mm.

[0041] (2) Selective laser melting: The mixed powder laid on the substrate surface in step (1) is selectively melted by laser. The laser power is 200W, the scanning speed is 1000mm / s, and the scanning interval is 0.09mm. Then another layer of mixed powder is laid, and selective laser melting is performed again. The process of laying mixed powder and selective laser melting is repeated until an alloy with a target thickness of 1mm is obtained.

[0042] (3) Deformation treatment: The alloy obtained in step (2) is subjected to warm rolling at 400°C for 30 minutes, and then subjected to cold rolling with a reduction of 50% per pass to obtain copper alloy.

[0043] Example 2: Preparation of copper alloys

[0044] A copper alloy, by mass fraction, comprises 2% Ti3O4 and the balance is Cu.

[0045] The preparation method of the above-mentioned copper alloy includes the following steps:

[0046] (1) Alloy powder mixing: Weigh and mix Cu powder and Ti3O4 powder (the particle size of copper powder is 100 micrometers and the particle size of Ti3O4 powder is 200 micrometers) to obtain mixed powder. Then spread the mixed powder evenly on the surface of the stainless steel substrate. The thickness of the mixed powder formed on the substrate surface is 0.1 mm.

[0047] (2) Selective laser melting: The mixed powder laid on the substrate surface in step (1) is selectively melted by laser. The laser power is 500W, the scanning speed is 800mm / s, and the scanning interval is 0.06mm. Then another layer of mixed powder is laid, and selective laser melting is performed again. The process of laying mixed powder and selective laser melting is repeated until an alloy with a target thickness of 0.5mm is obtained.

[0048] (3) Deformation treatment: The alloy obtained in step (2) is subjected to warm rolling at 450°C for 30 minutes, and then subjected to cold rolling with a reduction of 70% per pass to obtain copper alloy.

[0049] Example 3: Preparation of copper alloys

[0050] A copper alloy, by mass fraction, comprises 5% Ti3O4 and the balance is Cu.

[0051] The preparation method of the above-mentioned copper alloy includes the following steps:

[0052] (1) Alloy powder mixing: Weigh and mix Cu powder and Ti3O4 powder (the particle size of copper powder is 300 micrometers and the particle size of Ti3O4 powder is 0.1 micrometers) to obtain mixed powder. Then spread the mixed powder evenly on the surface of the stainless steel substrate. The thickness of the mixed powder formed on the substrate surface is 0.05 mm.

[0053] (2) Selective laser melting: The mixed powder laid on the substrate surface in step (1) is selectively melted by laser. The laser power is 600W, the scanning speed is 500mm / s, and the scanning interval is 0.03mm. Then another layer of mixed powder is laid, and selective laser melting is performed again. The process of laying mixed powder and selective laser melting is repeated until an alloy with a target thickness of 10mm is obtained.

[0054] (3) Deformation treatment: The alloy obtained in step (2) is subjected to warm rolling at 500°C for 30 minutes, and then subjected to cold rolling with a reduction of 90% per pass to obtain copper alloy.

[0055] Comparative Example 1

[0056] Compared with Example 1, the only difference in Comparative Example 1 is that, in the process of preparing the copper alloy in Comparative Example 1, an equal amount of Ti4O7 powder was used to replace Ti3O4 powder. The copper alloy obtained in Comparative Example 1 has a Ti4O7 content of 0.1% and the balance is Cu.

[0057] Comparative Example 2

[0058] Compared with Example 1, the only difference in Comparative Example 2 is that, by mass fraction, the copper alloy in Comparative Example 2 contains 8.5% Ti3O4 and the balance is Cu.

[0059] Product effectiveness test

[0060] The copper alloys prepared in Examples 1-3 and Comparative Examples 1-2 were tested for conductivity according to GB / T 3048.2-2007, and for tensile strength and elongation according to GB / T 228.1-2010. The test results are shown in Table 1, where 100% IACS = 1.7241 × 10⁻⁶. -8 Ωm.

[0061] Table 1

[0062]

[0063]

[0064] As can be seen from Table 1, the conductivity of the copper alloys in Examples 1-3 of this invention all exceeds 30% IACS, which is significantly higher than that of Comparative Examples 1-2. Furthermore, the copper alloys in Examples 1-3 of this invention also exhibit good tensile strength and elongation. Therefore, it is evident that the type and content of components in the copper alloys of this invention have a significant impact on the product performance.

Claims

1. A copper alloy, characterized in that, Including Cu and Ti3O4, its preparation method includes the following steps: (1) Alloy powder mixing: Cu powder and Ti3O4 powder are mixed to obtain a mixed powder, and then the mixed powder is spread on the surface of the substrate; (2) Selective laser melting: The mixed powder laid on the substrate surface in step (1) is selectively melted by laser, and then another layer of the mixed powder is laid, and then selective laser melting is performed again. The process of laying mixed powder and selective laser melting is repeated until the alloy of the target thickness is obtained. (3) Deformation treatment: The alloy obtained in step (2) is subjected to warm rolling and cold rolling to obtain the copper alloy; the temperature of the warm rolling treatment is 400-500℃; the cold rolling treatment is a cold rolling treatment with a reduction of 50-90% per pass. The Ti3O4 content is less than 8% of the mass of the copper alloy, with the balance being Cu.

2. The copper alloy according to claim 1, characterized in that, The Ti3O4 content is 0.1-7.5% by mass fraction.

3. The copper alloy according to claim 1, characterized in that, The Ti3O4 accounts for 0.1-5% by mass fraction.

4. The copper alloy according to claim 1, characterized in that, By mass fraction, Ti3O4 accounts for 0.1-5%.

5. The copper alloy according to any one of claims 1-4, characterized in that, The copper alloy has a conductivity exceeding 30% IACS; a compressive strength of not less than 800 MPa; and an elongation exceeding 10%.

6. The copper alloy according to claim 1, characterized in that, In step (1), the particle size of the copper powder is 0.2-320 micrometers; the particle size of the Ti3O4 powder is 0.1-220 micrometers.

7. The copper alloy according to claim 1, characterized in that, In step (1), the thickness of the mixed powder formed by spreading the mixed powder on the substrate surface is 0.01-0.5 mm; in step (2), when performing laser selective melting, the laser power is 200-600W, the scanning speed is 500-1000mm / s, and the scanning interval is 0.03-0.09mm; in step (2), the thickness of the alloy with the target thickness is 0.1-15mm.

8. A conductive element, characterized in that, Including the copper alloy described in any one of claims 1-7.

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