High-performance copper alloy for electronics

Abstract

The invention discloses a high-performance copper alloy for electronics, and relates to the technical field of electronic materials. Copper alloy is modified through nano silver and nano tin, molten metal permeates mutually under the high temperature condition, gaps between particles are filled, connection is tighter, and therefore the conductivity and mechanical property of a matrix are improved, and then alloy powder with aluminum, chromium and tungsten carbide as main components is subjected to laser energy radiation under the high oxygen pressure condition, so that the conductivity and mechanical property of the matrix are improved. A chromium sesquioxide oxidation film is firstly generated on the surface of the base body, so that the oxygen activity at the interface of the oxidation film is reduced, aluminum is promoted to form a compact, complete and continuous aluminum oxide protection film, then tungsten carbide forms a nucleation core, the surrounding structure is refined, and the mechanical property of the coating is improved; and the high-temperature oxidation resistance of the matrix is enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of electronic materials, in particular to a high-performance copper alloy for electronics. Background Art

[0002] With the continuous progress of human's understanding and transformation of nature, we have entered a modern society with highly developed electrification and electronic information. Integrated circuits, high-speed railway transportation, power transmission, cutting-edge industrial equipment and many other aspects closely related to social development and people's livelihood construction, which are widely used in electronic equipment, require the extensive participation of copper. Pure copper generally has good electrical conductivity, thermal conductivity, corrosion resistance and easy processing. However, its strength often cannot meet the relevant use requirements, so it needs to be strengthened; copper alloys are widely used in various industrial fields due to their excellent thermal conductivity, electrical conductivity and corrosion resistance. However, traditional copper alloys often partially sacrifice other properties such as electrical conductivity, thermal conductivity, corrosion resistance, etc. when strengthened, and cannot form good comprehensive use performance. In addition, under extreme conditions of long-term work, copper alloys are prone to various wear and corrosion failure phenomena, and the failure of copper alloys will cause huge economic losses to the production and manufacturing of engineering; therefore, it is particularly necessary to invent a high-performance copper alloy for electronics. Summary of the invention

[0003] The object of the present invention is to provide a high-performance copper alloy for electronics and a preparation method thereof, so as to solve the problems existing in the prior art.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: a high-performance copper alloy for electronics, which is prepared by coating a modified copper alloy with a coating formed by laser cladding of alloy powder.

[0005] Furthermore, the modified copper alloy is prepared by modifying the copper alloy with nano-silver and nano-tin under high temperature conditions.

[0006] Furthermore, a method for preparing a high-performance copper alloy for electronic use comprises the following preparation steps: (1) Mixing nanosilver, nanotin and copper alloy, performing vacuum melting, then pouring into a mold, and cooling to room temperature to obtain a modified copper alloy; (2) Under high oxygen pressure conditions, the alloy powder is coated with a modified copper alloy by laser cladding to obtain a high-performance copper alloy for electronic use.

[0007] Furthermore, the mass percentages of the copper alloy components in step (1) are: zinc 29%, manganese 3%, iron 2%, and copper 66%.

[0008] Furthermore, the vacuum degree in step (1) is 0.1 Pa.

[0009] Furthermore, the smelting temperature in step (1) is 950-1100° C. and the smelting time is 3-6 hours.

[0010] Furthermore, in step (1), the mass ratio of the nano-silver, nano-tin and copper alloy is 1:1-3:50.

[0011] Furthermore, the high oxygen pressure in step (2) is 260-350 kPa.

[0012] Furthermore, the mass percentages of the alloy powder components in step (2) are: 30% aluminum, 30% chromium, 15% tungsten carbide, 20% nickel, and 5% cobalt.

[0013] Furthermore, the laser cladding process parameters in step (2) are: laser power of 1500 W and scanning speed of 2 mm / s.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are: The invention enhances the electrical conductivity of the copper alloy by adding nano silver, and then adds tin particles. Under high temperature conditions, the molten metals penetrate each other and fill the gaps between the particles to make them more tightly connected, thereby improving the electrical conductivity. The silver oxide on the surface of the silver particles is decomposed into silver and oxygen, both of which react with tin. A part of them generates an intermetallic compound, which can limit the migration movement of silver ions and improve the stability of the matrix. The other part generates tin oxide, thereby enhancing the mechanical properties of the copper alloy and achieving the effect of high-temperature oxidation resistance. Then, under the condition of high oxygen pressure, the alloy powder mainly composed of aluminum, chromium and tungsten carbide is irradiated with laser energy, melted and solidified, and metallurgically combined with the matrix. In the initial stage of oxidation, a chromium oxide film is first generated on the surface of the matrix, so that the oxygen activity at the interface of the oxide film is reduced, and the aluminum is promoted to form a dense, complete and continuous aluminum oxide protective film. Then, the tungsten carbide forms a nucleation core, so that the surrounding tissue is refined, the mechanical properties of the coating are improved, and the high-temperature oxidation resistance of the matrix is ​​enhanced. DETAILED DESCRIPTION

[0015] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0016] In order to more clearly illustrate the method provided by the present invention, the following examples are used to describe in detail the various index testing methods of the electronic high-performance copper alloy prepared in the following examples are as follows: Conductivity: Take the same size of the embodiment and the comparative example and first calculate the resistance by the four-terminal network method, and then calculate the conductivity according to the sample size.

[0017] Resistance to high temperature oxidation: Take the embodiment and the comparative example of the same size, bake them at 300°C for 5 hours under oxygen conditions, take them out, cool them to room temperature, and record whether they change color.

[0018] Mechanical properties: Take the same size of the embodiment and the comparative example and refer to JIS Z2201 and JIS Z2241 to test the tensile strength of the samples.

[0019] Example 1 (1) Mixing nano silver, nano tin and copper alloy, smelting at 950° C. and vacuum degree of 0.1 Pa for 3 h, then pouring into a mold, and cooling to room temperature to obtain a modified copper alloy; the mass ratio of the nano silver, nano tin and copper alloy is 1:1:50; the mass percentages of the copper alloy components are: 29% zinc, 3% manganese, 2% iron and 66% copper; (2) Under oxygen conditions with an air pressure of 260 kPa, the alloy powder is coated with a modified copper alloy by laser cladding, and the process parameters are as follows: laser power of 1500 W, scanning speed of 2 mm / s, to obtain a high-performance copper alloy for electronics; the mass percentages of the alloy powder components are: 30% aluminum, 30% chromium, 15% tungsten carbide, 20% nickel, and 5% cobalt.

[0020] Example 2 (1) Mixing nanosilver, nanotin and copper alloy, smelting at 1025° C. and vacuum degree of 0.1 Pa for 4 hours, then pouring into a mold, and cooling to room temperature to obtain a modified copper alloy; the mass ratio of the nanosilver, nanotin and copper alloy is 1:2:50; the mass percentages of the copper alloy components are: 29% zinc, 3% manganese, 2% iron and 66% copper; (2) Under oxygen conditions with an air pressure of 310 kPa, the alloy powder is coated with a modified copper alloy by laser cladding, and the process parameters are as follows: laser power of 1500 W, scanning speed of 2 mm / s, to obtain a high-performance copper alloy for electronics; the mass percentages of the alloy powder components are: 30% aluminum, 30% chromium, 15% tungsten carbide, 20% nickel, and 5% cobalt.

[0021] Example 3 (1) Mixing nanosilver, nanotin and copper alloy, smelting at 1100° C. and vacuum degree of 0.1 Pa for 6 hours, then pouring into a mold, cooling to room temperature, and obtaining a modified copper alloy; the mass ratio of the nanosilver, nanotin and copper alloy is 1:3:50; the mass percentages of the copper alloy components are: 29% zinc, 3% manganese, 2% iron and 66% copper; (2) Under oxygen conditions with an air pressure of 350 kPa, the alloy powder is coated with a modified copper alloy by laser cladding, and the process parameters are as follows: laser power of 1500 W, scanning speed of 2 mm / s, to obtain a high-performance copper alloy for electronics; the mass percentages of the alloy powder components are: 30% aluminum, 30% chromium, 15% tungsten carbide, 20% nickel, and 5% cobalt.

[0022] Comparative Example 1 The difference between Comparative Example 1 and Example 2 is that step (1) is different. Step (1) is changed to: nano-tin and copper alloy are mixed, smelted at 1025° C. and a vacuum degree of 0.1 Pa for 4 h, then poured into a mold, and cooled to room temperature to obtain a modified copper alloy; the mass ratio of the nano-tin to the copper alloy is 2:50; the mass percentages of the copper alloy components are: zinc 29%, manganese 3%, iron 2%, and copper 66%; the remaining steps are the same as Example 2.

[0023] Comparative Example 2 The difference between Comparative Example 2 and Example 2 is that step (1) is different. Step (1) is changed to: mixing nanosilver and copper alloy, smelting at 1025° C. and a vacuum degree of 0.1 Pa for 4 h, then pouring into a mold, cooling to room temperature, to obtain a modified copper alloy; the mass ratio of the nanosilver to the copper alloy is 1:50; the mass percentages of the copper alloy components are: 29% zinc, 3% manganese, 2% iron, and 66% copper; the remaining steps are the same as Example 2.

[0024] Comparative Example 3 The difference between Comparative Example 3 and Example 2 is that step (1) is omitted; the remaining steps are the same as those of Example 2.

[0025] Comparative Example 4 The difference between Comparative Example 4 and Example 2 is that step (2) is different. Step (2) is changed to: under the condition of oxygen pressure of 310 kPa, the alloy powder is coated with modified copper alloy by laser cladding, and its process parameters are: laser power of 1500 W, scanning speed of 2 mm / s, to obtain high-performance copper alloy for electronics; the mass percentages of the alloy powder components are: 45% chromium, 30% tungsten carbide, 20% nickel, and 5% cobalt; the remaining steps are the same as those in Example 2.

[0026] Comparative Example 5 The difference between Comparative Example 5 and Example 2 is that step (2) is different. Step (2) is changed to: under the condition of oxygen pressure of 310 kPa, the alloy powder is coated with modified copper alloy by laser cladding, and its process parameters are: laser power of 1500 W, scanning speed of 2 mm / s, to obtain high-performance copper alloy for electronics; the mass percentages of the alloy powder components are: aluminum 45%, tungsten carbide 30%, nickel 20%, cobalt 5%; the remaining steps are the same as Example 2.

[0027] Comparative Example 6 The difference between Comparative Example 6 and Example 2 is that step (2) is different. Step (2) is changed to: under the condition of oxygen pressure of 310 kPa, the alloy powder is coated with modified copper alloy by laser cladding, and its process parameters are: laser power of 1500 W, scanning speed of 2 mm / s, to obtain high-performance copper alloy for electronics; the mass percentages of the alloy powder components are: aluminum 40%, chromium 35%, nickel 20%, and cobalt 5%; the remaining steps are the same as Example 2.

[0028] Comparative Example 7 The difference between Comparative Example 7 and Example 2 is that step (2) is different. Step (2) is changed to: the alloy powder is coated with a modified copper alloy by laser cladding, and the process parameters are: laser power of 1500 W, scanning speed of 2 mm / s, to obtain a high-performance copper alloy for electronics; the mass percentages of the alloy powder components are: 30% aluminum, 30% chromium, 15% tungsten carbide, 20% nickel, and 5% cobalt; the remaining steps are the same as in Example 2.

[0029] Comparative Example 8 The difference between Comparative Example 8 and Example 2 is that there is no step (2); the remaining steps are the same as Example 2.

[0030] Effect example Table 1 below shows the performance analysis results of the electronic high performance copper alloys using Examples 1 to 3 of the present invention and Comparative Examples 1 to 7.

[0031] Table 1 From the comparison of the experimental results of the embodiment and the comparative example in Table 1, it can be found that the present invention utilizes nano-silver and nano-tin to modify the copper alloy. Under high temperature conditions, the molten metals penetrate each other and fill the gaps between the particles to make them more closely connected, thereby improving the conductivity. The silver oxide on the surface of the silver particles is decomposed into silver and oxygen, both of which react with tin, and a part of them generates intermetallic compounds, which can limit the migration and movement of silver ions and improve the stability of the matrix, and the other part generates tin oxide, thereby enhancing the mechanical properties of the copper alloy and achieving the effect of high-temperature oxidation resistance. Then, under the condition of high oxygen pressure, the alloy powder mainly composed of aluminum, chromium, and tungsten carbide is irradiated with laser energy, melted and solidified, and metallurgically combined with the matrix, first generating a chromium oxide film, so that the oxygen activity at the interface of the oxide film is reduced, and the aluminum is promoted to form a dense, complete and continuous aluminum oxide protective film. Then, the tungsten carbide forms a nucleation core, which refines the surrounding tissue, improves the mechanical properties of the coating, and enhances the high-temperature oxidation resistance of the matrix.

[0032] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any marking in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A high-performance copper alloy for electronics, characterized in that: The method comprises the following preparation steps: (1) Mixing nanosilver, nanotin and copper alloy, smelting at 1025° C. and vacuum degree of 0.1 Pa for 4 hours, then pouring into a mold, and cooling to room temperature to obtain a modified copper alloy; the mass ratio of the nanosilver, nanotin and copper alloy is 1:2:50; the mass percentages of the copper alloy components are: 29% zinc, 3% manganese, 2% iron and 66% copper; (2) Under oxygen conditions with an air pressure of 310 kPa, the alloy powder is coated with a modified copper alloy by laser cladding, and the process parameters are as follows: laser power of 1500 W, scanning speed of 2 mm / s, to obtain a high-performance copper alloy for electronics; the mass percentages of the alloy powder components are: 30% aluminum, 30% chromium, 15% tungsten carbide, 20% nickel, and 5% cobalt.

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