Preparation method of high-performance dispersion copper alloy

Abstract

The invention discloses a preparation method of a high-performance dispersion copper alloy, according to the scheme, nano Al2O3 particles are obtained through internal oxidation, a nanoscale Cr phase is separated out through aging, the nano Al2O3 particles help to hinder recrystallization of the Cr phase at the same time, specific aging treatment steps are adopted, and aging treatment is conducted twice, so that the high-performance dispersion copper alloy is obtained. The Al element is promoted to be combined with residual oxygen and the like at the specific temperature to form new Al2O3 particles, and the mechanical property of the copper alloy is further improved under the cooperation.

Description

Technical Field

[0001] This invention relates to the field of alloy technology, and specifically to a method for preparing high-performance dispersed copper alloys. Background Technology

[0002] Al2O3 dispersion-strengthened copper alloys are widely used in high-voltage power transmission, aerospace, and rail transit lighting due to their excellent mechanical and electrical properties. For example, patent document CN109576529B discloses a method for preparing a dispersion-strengthened copper alloy, which adds Cr to the copper alloy components to improve its electrical conductivity and tensile strength, resulting in excellent performance. However, its tensile strength still does not meet the requirements of applications such as rail transit and aerospace, and further improvements are needed. Summary of the Invention

[0003] To address at least one of the aforementioned technical deficiencies, the present invention provides the following technical solution:

[0004] This application discloses a method for preparing high-performance dispersion copper alloys, including the following steps:

[0005] First, atomized Cu-Al alloy powder is mixed with an oxidant for internal oxidation treatment and then crushed and reduced to obtain dispersion-strengthened copper alloy powder.

[0006] Second, the dispersion-strengthened copper alloy powder is mixed with Cu-Cr atomized alloy powder and pressed to obtain a billet;

[0007] Third, the billet is subjected to cold isostatic pressing;

[0008] Fourth, after the cold isostatic pressing treatment, the billet is encased and formed, and then subjected to the first aging treatment at a temperature of 640-660℃ for 30-60 minutes.

[0009] Fifth, after the billet has cooled to 360-450℃ after the first aging treatment, a second aging treatment is carried out at a temperature of 670-720℃ for 30-60 minutes.

[0010] This solution obtains nano-Al2O3 particles through internal oxidation and precipitates nano-scale Cr phase through aging. The nano-Al2O3 particles also help to inhibit the recrystallization of the Cr phase. Furthermore, our company employs specific aging treatment steps, performing two aging treatments at specific temperatures, which helps to promote the combination of Al elements with residual oxygen to form new Al2O3 particles. This combination helps to further improve the mechanical properties of copper alloys.

[0011] Furthermore, by mass, Al accounts for 0.3-1.0% of the copper alloy, and Cr accounts for 0.2-0.4% of the copper alloy.

[0012] Furthermore, during the internal oxidation treatment, the oxidant is Cu2O, the mass ratio of the oxidant to Cu-Al alloy powder is 0.002-0.06:1, the oxidation temperature is 800-900℃, and the treatment time is 4-8h.

[0013] Furthermore, the reduction process is carried out in a hydrogen atmosphere at a temperature of 800-900℃ for 4-8 hours.

[0014] Furthermore, during the encapsulation process, the extrusion ratio is 15-20:1, and the cold forging deformation is 60-75%.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] 1. This invention defines the composition of the copper alloy and a specific preparation method. The combination of Cr phase and nano-Al2O3 particles helps to further improve the mechanical properties of the copper alloy. Detailed Implementation

[0017] The present invention will be further described below with reference to specific embodiments.

[0018] Example 1

[0019] A method for preparing high-performance dispersion copper alloys includes the following steps:

[0020] First, atomized Cu-Al alloy powder (particle size 20-40 mesh) is mixed with oxidant Cu2O. The mass ratio of atomized Cu-Al alloy powder to oxidant is 1:0.01. Then, internal oxidation treatment is carried out at 850℃ for 5 hours. After treatment, the powder is crushed (passed through a 100-mesh sieve) and reduced to obtain dispersion-strengthened copper alloy powder. The reduction process parameters are as follows: carried out in a hydrogen atmosphere, reduction temperature 860℃, reduction time 7 hours.

[0021] Second, the dispersion-strengthened copper alloy powder is mixed with Cu-Cr atomized alloy powder and pressed to obtain a billet. The pressing pressure is 500 MPa.

[0022] Third, the billet is cold isostatically pressed into round ingots.

[0023] Fourth, after the billet is cold isostatically pressed, it is encased in a sleeve and then subjected to the first aging treatment at a temperature of 650℃ for 40 minutes. The sleeve forming process is as follows: the round ingot is encased in pure copper and then subjected to water-sealed hot extrusion at 900℃ with an extrusion ratio of 16 and an extrusion speed of 3cm / s. The forging deformation is 66% to obtain a bar, which is then subjected to the first aging treatment.

[0024] Fifth, after the billet has been air-cooled to 400℃ after the first aging treatment, a second aging treatment is performed at 700℃ for 50 minutes. After air cooling, the copper alloy material required for forming is formed. The material contains 0.6% Al and 0.3% Cr by mass, with the remainder being copper.

[0025] Example 2

[0026] A method for preparing high-performance dispersion copper alloys includes the following steps:

[0027] First, atomized Cu-Al alloy powder (particle size 20-40 mesh) is mixed with oxidant Cu2O. The mass ratio of atomized Cu-Al alloy powder to oxidant is 1:0.02. Then, internal oxidation treatment is carried out at 900℃ for 6 hours. After treatment, the powder is crushed (passed through a 100-mesh sieve) and reduced to obtain dispersion-strengthened copper alloy powder. The reduction process parameters are as follows: carried out in a hydrogen atmosphere, reduction temperature 820℃, and reduction time 6 hours.

[0028] Second, the dispersion-strengthened copper alloy powder is mixed with Cu-Cr atomized alloy powder and pressed to obtain a billet. The pressing pressure is 540 MPa.

[0029] Third, the billet is cold isostatically pressed into round ingots.

[0030] Fourth, after the billet is cold isostatically pressed, it is encased in a sleeve and then subjected to the first aging treatment at a temperature of 660℃ for 30 minutes. The sleeve forming process is as follows: the round ingot is encased in pure copper and then subjected to water-sealed hot extrusion at 910℃ with an extrusion ratio of 16 and an extrusion speed of 3.5cm / s. The forging deformation is 65% to obtain a bar, which is then subjected to the first aging treatment.

[0031] Fifth, after the billet has been air-cooled to 400℃ after the first aging treatment, a second aging treatment is performed at 710℃ for 40 minutes. After air cooling, the copper alloy material required for forming is formed. The material contains 0.8% Al and 0.4% Cr by mass, with the remainder being copper.

[0032] Comparative Example 1

[0033] Compared with Example 1, the difference is that the temperature in the fifth step is 600°C, while the rest are the same.

[0034] Comparative Example 2

[0035] Compared with Example 1, the difference is that there is no cooling after the fourth step, and the temperature is directly increased for the second aging treatment.

[0036] Comparative Example 3

[0037] Compared with Example 1, the difference is: aging treatment: 640℃ for 90 minutes.

[0038] The performance of the prepared copper alloy is shown in Table 1.

[0039] Table 1

[0040] tensile strength conductivity Example 1 887 74.6 Example 2 906 70.7 Comparative Example 1 843 76.8 Comparative Example 2 765 80.6 Comparative Example 3 813 81.7

[0041] As can be seen, under the molding scheme defined in this invention, the molded copper alloy exhibits a breakthrough improvement in tensile strength while maintaining high electrical conductivity, meeting market demands. According to testing, the alumina content in the composition increases after aging treatment, leading to an increase in the tensile strength of the copper alloy.

[0042] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing high-performance dispersion copper alloys, characterized in that, Includes the following steps: First, atomized Cu-Al alloy powder is mixed with an oxidant for internal oxidation treatment and then crushed and reduced to obtain dispersion-strengthened copper alloy powder. Second, the dispersion-strengthened copper alloy powder is mixed with Cu-Cr atomized alloy powder and pressed to obtain a billet; Third, the billet is subjected to cold isostatic pressing; Fourth, after the cold isostatic pressing treatment, the billet is encased and formed, and then subjected to the first aging treatment at a temperature of 640-660℃ for 30-60 minutes. Fifth, after the billet has cooled to 360-450℃ after the first aging treatment, a second aging treatment is carried out at a temperature of 670-720℃ for 30-60 minutes.

2. The method for preparing the high-performance dispersion copper alloy as described in claim 1, characterized in that: By mass, Al accounts for 0.3-1.0% of copper alloys, and Cr accounts for 0.2-0.4%.

3. The method for preparing the high-performance dispersion copper alloy as described in claim 1, characterized in that: During internal oxidation treatment, the oxidant is Cu2O, the mass ratio of oxidant to Cu-Al alloy powder is 0.002-0.06:1, the oxidation temperature is 800-900℃, and the treatment time is 4-8h.

4. The method for preparing the high-performance dispersion copper alloy as described in claim 1, characterized in that: The reduction process is carried out in a hydrogen atmosphere at a temperature of 800-900℃ for 4-8 hours.

5. The method for preparing the high-performance dispersion copper alloy as described in claim 1, characterized in that: During the sheathing process, the extrusion ratio is 15-20:1, and the cold forging deformation is 60-75%.