CN110004322B

CN110004322B - Copper-based microcrystalline alloy, preparation method thereof and electronic product

Info

Publication number: CN110004322B
Application number: CN201810011647.2A
Authority: CN
Inventors: 宫清; 郭强; 王梦得; 安维; 房斌
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2018-01-05
Filing date: 2018-01-05
Publication date: 2021-05-14
Anticipated expiration: 2038-01-05
Also published as: CN110004322A

Abstract

The invention discloses a copper-based microcrystal alloy and a preparation method thereof and an electronic product adopting the copper-based microcrystal alloy, wherein the copper-based microcrystal alloy contains 30-60% of Cu, 25-40% of Mn, 4-6% of Al, 10-17% of Ni, 0.01-10% of Si, 0.001-0.03% of Be and 0.01-3% of Sn in percentage by weight based on the total amount of the copper-based microcrystal alloy. The copper-based microcrystal alloy has better mechanical property and obviously improved corrosion resistance. The copper-based microcrystalline alloy has good flowing property and good formability, and can be processed by a die-casting process, so that the surface precision of a product can be obviously improved, and the copper-based microcrystalline alloy is suitable for preparing an appearance decoration part with high requirements on the surface precision.

Description

Copper-based microcrystalline alloy, preparation method thereof and electronic product

Technical Field

The invention relates to a copper-based microcrystalline alloy and a preparation method thereof, and also relates to an electronic product adopting the copper-based microcrystalline alloy.

Background

The copper alloy is a metal with good heat conduction, electric conduction, diamagnetism and good ductility, and has wide application in the fields of electricity, spaceflight, household appliances, transportation and the like. With the increasing demands of the market for other special properties such as precision, complexity, wear resistance and the like of copper alloy parts, researchers pay more and more attention to the strength, formability and machinability of the copper alloy parts.

With the metallization of electronic products, a trend in the market has been reached. Electronic products including intelligent terminals continuously demand performance improvement, and in addition, new experience is given to users in the aspects of texture and attractiveness in the aspect of appearance industrial design.

However, the corrosion resistance and mechanical strength of copper alloy are low, the casting performance is not ideal enough, and the technical requirements of modern products are difficult to meet.

Therefore, there is a need to develop a copper alloy that combines good corrosion resistance and high mechanical strength and is also suitable for die casting.

Disclosure of Invention

The invention aims to overcome the defect that the corrosion resistance and the mechanical strength of the copper alloy are difficult to be considered simultaneously, and provides the copper-based microcrystalline alloy which not only has higher mechanical strength, but also shows obviously improved corrosion resistance.

According to a first aspect of the present invention, there is provided a copper-based microcrystalline alloy comprising, in weight percent based on the total amount of the copper-based microcrystalline alloy:

according to a second aspect of the present invention, there is provided a method for producing the copper-based microcrystalline alloy according to the first aspect of the present invention, which comprises melting the alloy raw material, and then sequentially carrying out casting and cooling.

According to a third aspect of the present invention, there is provided an electronic product comprising a structural member made of a material containing the copper-based microcrystalline alloy according to the first aspect of the present invention.

The copper-based microcrystal alloy has higher mechanical strength and obviously improved corrosion resistance.

The copper-based microcrystal alloy has good flowing property and good formability. More importantly, the copper-based microcrystalline alloy can be processed by a die-casting process, so that the surface precision of a product can be remarkably improved, and the copper-based microcrystalline alloy is suitable for preparing an appearance decoration with higher requirements on the surface precision.

Detailed Description

the copper-based microcrystalline alloy according to the present invention may have a manganese (Mn) content of 25 to 40% by weight, for example, 25%, 25.5%, 26%, 26.5%, 27%, 27.5%, 28%, 28.5%, 29%, 29.5%, 30%, 30.5%, 31%, 31.5%, 32%, 32.5%, 33%, 33.5%, 34%, 34.5%, 35%, 35.5%, 36%, 36.5%, 37%, 37.5%, 38%, 38.5%, 39%, 39.5%, or 40% based on the total amount of the copper-based microcrystalline alloy. Preferably, the Mn content is 28-35%, for example 28.5-33%, in weight percent, based on the total copper-based microcrystalline alloy.

The copper-based microcrystalline alloy according to the present invention may have a nickel (Ni) content of 10 to 17% by weight, for example, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, 15%, 15.5%, 16%, 16.5%, or 17% based on the total amount of the copper-based microcrystalline alloy. Preferably, the Ni content is 11-15%, for example 12-15% in weight percent, based on the total amount of the copper-based microcrystalline alloy.

According to the copper-based microcrystalline alloy of the present invention, from the viewpoint of further improving the corrosion resistance and surface accuracy of the copper-based microcrystalline alloy, and further improving the formability of the copper-based microcrystalline alloy, the weight ratio of Mn/Ni in the copper-based microcrystalline alloy is preferably 1.5 to 4: 1, more preferably 1.6 to 3.5: 1, more preferably 2 to 2.5: 1, more preferably 2.1 to 2.4: 1.

the copper-based microcrystalline alloy according to the present invention has an aluminum (Al) content of 4 to 6% by weight, for example, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, 4.6%, 4.7%, 4.8%, 4.9%, 5%, 5.1%, 5.2%, 5.3%, 5.4%, 5.5%, 5.6%, 5.7%, 5.8%, 5.9%, or 6% based on the total amount of the copper-based microcrystalline alloy. When the content of aluminum is less than 4 wt%, the copper-based microcrystalline alloy has poor formability, large grain size, low mechanical properties and surface accuracy, and poor corrosion resistance. When the content of aluminum is higher than 6%, the corrosion resistance of the copper-based microcrystalline alloy is remarkably reduced, and meanwhile, the copper-based microcrystalline alloy has large grain size and reduced mechanical properties. From the viewpoint of further improving the mechanical properties and corrosion resistance of the copper-based microcrystalline alloy, the content of Al in the copper-based microcrystalline alloy is preferably 4.5 to 5.5%, for example, 4.5 to 5% in terms of weight percentage based on the total amount of the copper-based microcrystalline alloy.

The copper-based microcrystalline alloy according to the present invention may contain silicon (Si) in an amount of 0.01 to 6% by weight, for example, 0.01%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, or 6% based on the total amount of the copper-based microcrystalline alloy. Si is introduced into the copper-based microcrystalline alloy to further refine crystal grains and improve the mechanical strength of the copper-based microcrystalline alloy. The surface precision of the copper-based microcrystal alloy can be further improved by introducing Si into the copper-based microcrystal alloy. The copper-based microcrystalline alloy according to the present invention preferably contains Si in an amount of 0.1 to 5.5 wt%, more preferably 0.1 to 2.5 wt%, based on the total amount of the copper-based microcrystalline alloy.

The copper-based microcrystalline alloy according to the present invention may have a beryllium (Be) content of 0.001 to 0.03% by weight, for example, 0.001%, 0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%, 0.011%, 0.012%, 0.013%, 0.014%, 0.015%, 0.016%, 0.017%, 0.018%, 0.019%, 0.02%, 0.021%, 0.022%, 0.023%, 0.024%, 0.025%, 0.026%, 0.027%, 0.028%, 0.029%, or 0.03% based on the total amount of the copper-based microcrystalline alloy. By introducing Be into the copper-based microcrystalline alloy, the fluidity can Be improved, the forming performance of the copper-based microcrystalline alloy can Be improved, crystal grains can Be effectively refined, and the surface precision, the mechanical strength and the corrosion resistance of the copper-based microcrystalline alloy can Be improved. However, when the content of Be in the copper-based microcrystalline alloy is more than 0.03% by weight, the corrosion resistance, formability and surface accuracy of the copper-based microcrystalline alloy are significantly deteriorated, while the mechanical strength of the copper-based microcrystalline alloy is adversely affected. The copper-based microcrystalline alloy according to the present invention preferably contains Be in an amount of 0.005 to 0.01% by weight based on the total amount of the copper-based microcrystalline alloy.

According to the copper-based microcrystalline alloy of the present invention, the copper-based microcrystalline alloy contains tin (Sn). The Sn is introduced into the copper-based microcrystal alloy, so that the corrosion resistance of the copper-based microcrystal alloy can be further improved. The copper-based microcrystalline alloy according to the present invention may contain 0.01 to 3% by weight of Sn, for example, 0.01%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, 1%, 1.5%, 2%, 2.5%, or 3% based on the total amount of the copper-based microcrystalline alloy. The copper-based microcrystalline alloy according to the present invention preferably contains Sn in an amount of 0.05 to 2.5 wt%, more preferably 0.5 to 1.5 wt%, based on the total amount of the copper-based microcrystalline alloy.

The copper-based microcrystalline alloy according to the present invention preferably has a copper (Cu) content of 40 to 57%, more preferably 40 to 55%, in weight percent, based on the total amount of the copper-based microcrystalline alloy.

According to the copper-based microcrystalline alloy of the present invention, the grain size of the copper-based microcrystalline alloy is small. Generally, the copper-based microcrystalline alloy according to the present invention has an average grain size of 1 to 8 micrometers, preferably 1.2 to 5 micrometers, more preferably 1.5 to 3.5 micrometers. In the present invention, the average grain size is measured by the method specified in GB/T6394-2002.

According to the copper-based microcrystalline alloy of the present invention, the surface roughness Ra of the copper-based microcrystalline alloy may be 0.1 to 0.9, preferably 0.2 to 0.5, and more preferably 0.25 to 0.3. In the present invention, the surface roughness Ra is measured by the method specified in GB/T6458-86.

According to a second aspect of the present invention, there is provided a method for producing the copper-based microcrystalline alloy according to the first aspect of the present invention, the method comprising melting alloy raw materials, and then sequentially carrying out casting and cooling to obtain the copper-based microcrystalline alloy according to the present invention.

According to the method of the present invention, the melting is preferably vacuum melting. The melting is preferably carried out at a temperature of 1100 ℃ and 1250 ℃.

The method according to the invention preferably comprises die casting the cooled alloy ingot to form a shaped body having the desired shape.

According to the method of the invention, in a preferred embodiment, said die casting is preferably semi-solid die casting. According to this preferred embodiment, the grain size of the copper-based microcrystalline alloy can be further refined, and defects in the product can be reduced.

According to this preferred embodiment, the semi-solid die casting may be performed under conventional semi-solid die casting process conditions. Preferably, the casting temperature is 950-.

The copper-based microcrystalline alloy has good mechanical property and corrosion resistance, and can be molded by a die-casting process, so that a product has good surface precision and is suitable for manufacturing structural components of electronic products.

Thus, according to a third aspect of the present invention, there is provided an electronic product comprising a structural member made of a material containing the copper-based microcrystalline alloy according to the first aspect of the present invention.

According to the electronic product of the present invention, the structural member is preferably an appearance member.

According to the electronic product of the invention, the electronic product is preferably a mobile phone. The microcrystal alloy can be used for manufacturing an appearance frame of a mobile phone. In a preferred embodiment, the middle frame of the mobile phone is made of a material containing the copper-based microcrystalline alloy of the invention.

The present invention will be described in detail with reference to examples, but the scope of the present invention is not limited thereto.

The following examples and comparative examples relate to the following test methods.

(1) Surface roughness test

The surface roughness was measured by the method specified in GB/T1031-1995.

(2) Corrosion resistance test

The corrosion resistance of the copper-based microcrystal alloy is measured by a method specified in GB/T6458-86.

(3) Tensile Strength test

Part 1 of the tensile test of metallic materials according to GB/T228.1-2010: the tensile strength of the copper-based microcrystalline alloy was measured by the method specified in the room temperature test method.

(4) Hardness test

According to GB/T4340.4-2009 Vickers hardness test part 4 of metal materials: hardness value table, the Vickers hardness test is carried out on the polished test surface, the test force is 10kg, and the number of the measurement points is 5 to take an average value.

(5) Grain size test

The average grain size of the copper-based microcrystalline alloy was measured by the method specified in GB/T6394-2002.

(6) Fluidity test

Adopting a single spiral fluidity sample mold with a cross section size of 5.5mm × 3mm and a soup feeding capacity of 45cm³The injection speed was 1 m/s.

(7) Formability test

And (4) carrying out forming test by adopting a die-casting forming integrity method of the middle frame of the mobile phone.

The 'excellent' means that the outer surface of the middle frame is bright and is integrally formed, each detail structure is integrally formed, and the middle frame is free from breakage and sticking to a die;

good means that the outer surface of the middle frame is bright and is integrally formed, and each detail structure is integrally formed without fracture;

the general method means that the outer part of the middle frame is integrally formed, each detail structure is integrally formed, and no fracture occurs;

poor means that the middle frame is completely formed, and part of the fine knot structure is not formed;

the 'poor' means that the middle frame is not formed completely, and part of the fine knot structure is not formed.

Examples 1-13 are intended to illustrate the invention.

Example 1

Copper-based microcrystalline alloy raw materials were prepared according to the compositions of table 1. Vacuum melting is carried out on the copper-based microcrystal alloy raw material. The vacuum melting process comprises the following steps: and (3) vacuumizing to below 5Pa by using a vacuum smelting furnace, introducing argon, preheating the furnace body for 5 minutes under 20kW, heating to 1120 ℃ under 50-60kW, and carrying out heat preservation for 8 minutes to obtain a cast ingot.

After the obtained ingot was melted, semi-solid die casting was performed on a cold die casting machine DCC160 to obtain a die cast body of the copper-based microcrystalline alloy of the present invention. Wherein, the semi-solid die casting conditions comprise: the casting temperature is 980 ℃, the injection speed is 1m/s, the die cavity temperature is 230 ℃, the heat preservation time is 4s, the primary injection starting point is 150mm, and the secondary injection starting point is 195 mm.

The property parameters of the copper-based microcrystalline alloy produced are listed in table 2.

Examples 2 to 3

A copper-based microcrystalline alloy was produced in the same manner as in example 1, except that a raw material for the copper-based microcrystalline alloy was prepared in accordance with the composition given in table 1. The property parameters of the copper-based microcrystalline alloy produced are listed in table 2.

In embodiment 2, the semi-solid die casting conditions include: the casting temperature is 950 ℃, the injection speed is 1.2m/s, the die cavity temperature is 230 ℃, the heat preservation time is 5s, the starting point of the first injection is 150mm, and the starting point of the second injection is 200 mm;

in example 3, the conditions of the semi-solid die casting include: the casting temperature is 950 ℃, the injection speed is 1.5m/s, the die cavity temperature is 230 ℃, the heat preservation time is 5s, the primary injection starting point is 150mm, and the secondary injection starting point is 200 mm.

Examples 4, 5 and 13

Examples 6, 7 and 10 to 12

A copper-based microcrystalline alloy was produced in the same manner as in example 2, except that a raw material for the copper-based microcrystalline alloy was prepared in accordance with the composition given in table 1. The property parameters of the copper-based microcrystalline alloy produced are listed in table 2.

Examples 8 and 9

A copper-based microcrystalline alloy was produced in the same manner as in example 3, except that a copper-based microcrystalline alloy raw material was prepared in accordance with the composition given in table 1. The property parameters of the copper-based microcrystalline alloy produced are listed in table 2.

Comparative examples 1 to 5, 9, 10 and 12

A copper-based microcrystalline alloy was produced in the same manner as in example 1, except that a copper-based microcrystalline alloy raw material was prepared in accordance with the composition of table 1. The property parameters of the copper-based microcrystalline alloy produced are listed in table 2.

Comparative examples 6 to 7

A copper-based microcrystalline alloy was produced in the same manner as in example 3, except that a copper-based microcrystalline alloy raw material was prepared in accordance with the composition shown in table 1. The property parameters of the copper-based microcrystalline alloy produced are listed in table 2.

Comparative examples 8 and 11

A copper-based microcrystalline alloy was produced in the same manner as in example 2, except that a copper-based microcrystalline alloy raw material was prepared in accordance with the composition shown in table 1. The property parameters of the copper-based microcrystalline alloy produced are listed in table 2.

TABLE 1 (based on the total amount of the copper-based microcrystalline alloy, in weight percent)

TABLE 2

As can be seen from the results of table 2, the copper-based microcrystalline alloy according to the present invention has not only higher mechanical strength but also better corrosion resistance. The copper-based microcrystalline alloy can be formed by a die-casting process, and a product has obviously improved surface precision.

Comparing example 1 with comparative examples 1 to 3, it can be seen that the copper-based microcrystalline alloy according to the present invention can effectively refine crystal grains, improve mechanical strength of products, and improve corrosion resistance and surface accuracy, as well as fluidity of melt and moldability by introducing silicon, beryllium and tin into the alloy.

Comparing example 1 with comparative example 4, it can be seen that when the beryllium content in the alloy is too high, the corrosion resistance of the copper-based microcrystalline alloy is reduced, and the mechanical properties and the formability of the copper-based microcrystalline alloy are also deteriorated.

Comparing example 1 with comparative example 5, it can be seen that when the content of silicon in the alloy is too high, the surface accuracy and formability of the copper-based microcrystalline alloy are significantly deteriorated, while the corrosion resistance of the copper-based microcrystalline alloy is also adversely affected.

Comparing example 3 with comparative examples 6 and 7, it can be seen that the too high aluminum content in the alloy results in the enlargement of the grain size of the copper-based microcrystalline alloy and the deterioration of the corrosion resistance of the copper-based microcrystalline alloy, and that when the too low aluminum content, the enlargement of the grain size of the copper-based microcrystalline alloy results in the deterioration of the surface precision and the corrosion resistance, and at the same time, the adverse effect is generated on the formability of the copper-based microcrystalline alloy, resulting in the remarkable deterioration of the formability of the copper-based microcrystalline alloy.

Comparing example 2 with comparative example 8, it can be seen that the manganese content in the copper-based microcrystalline alloy is too high, which results in deterioration of surface accuracy and corrosion resistance of the copper-based microcrystalline alloy, and poor formability of the copper-based microcrystalline alloy. Comparing example 1 with comparative example 9, it can be seen that the excessively low manganese content in the copper-based microcrystalline alloy results in the deterioration of the formability of the copper-based microcrystalline alloy, and at the same time, the grain size of the copper-based microcrystalline alloy becomes large, the surface accuracy becomes poor, and the mechanical properties become low.

Comparing example 1 with comparative example 10, it can be seen that the too low nickel content in the copper-based microcrystalline alloy results in larger grain size, lower mechanical properties, poorer surface precision and corrosion resistance, and poorer formability of the copper-based microcrystalline alloy. Comparing example 2 with comparative example 11, it can be seen that the too high nickel content in the copper-based microcrystalline alloy results in a significant increase in grain size, a decrease in mechanical properties, a decrease in surface accuracy, and a deterioration in formability.

Comparing example 1 with comparative example 12, it can be seen that when the tin content in the copper-based microcrystalline alloy is too high, the mechanical properties of the copper-based microcrystalline alloy are reduced, and the corrosion resistance and formability are reduced.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. The copper-based microcrystalline alloy comprises the following components in percentage by weight based on the total amount of the copper-based microcrystalline alloy:

2. a copper-based microcrystalline alloy according to claim 1, wherein the content of Mn is 28-35% by weight based on the total amount of the copper-based microcrystalline alloy.

3. A copper-based microcrystalline alloy according to claim 1, wherein Ni is contained in an amount of 11 to 15% by weight based on the total amount of the copper-based microcrystalline alloy.

4. Copper-based microcrystalline alloy according to any one of claims 1 to 3, wherein the weight ratio of Mn/Ni in the copper-based microcrystalline alloy is 1.5 to 4: 1.

5. copper-based microcrystalline alloy according to claim 4, wherein the weight ratio of Mn/Ni in said copper-based microcrystalline alloy is 1.6-3.5: 1.

6. a copper-based microcrystalline alloy according to claim 5, wherein a weight ratio of Mn/Ni in said copper-based microcrystalline alloy is 2-2.5: 1.

7. copper-based microcrystalline alloy according to any one of claims 1 to 3, wherein Al is present in an amount of 4.5 to 5.5% by weight based on the total amount of the copper-based microcrystalline alloy.

8. A copper-based microcrystalline alloy according to any one of claims 1 to 3, wherein the content of Si is 0.1 to 5.5% by weight based on the total amount of the copper-based microcrystalline alloy.

9. A copper-based microcrystalline alloy according to claim 8, wherein Si is contained in an amount of 0.1 to 2.5% by weight based on the total amount of the copper-based microcrystalline alloy.

10. A copper-based microcrystalline alloy according to any one of claims 1 to 3, wherein Be is contained in an amount of 0.005 to 0.01% by weight based on the total amount of the copper-based microcrystalline alloy.

11. A copper-based microcrystalline alloy according to any one of claims 1 to 3, wherein the content of Sn is 0.05 to 2.5% by weight based on the total amount of the copper-based microcrystalline alloy.

12. A copper-based microcrystalline alloy according to claim 11, wherein the content of Sn is 0.5-1.5% by weight based on the total amount of the copper-based microcrystalline alloy.

13. Copper-based microcrystalline alloy according to any one of claims 1 to 3, wherein the average grain size of the copper-based microcrystalline alloy is 1 to 8 μm.

14. Copper base microcrystalline alloy according to claim 13, wherein the average grain size of the copper base microcrystalline alloy is 1.2-5 μm.

15. Copper base microcrystalline alloy according to claim 14, wherein the average grain size of the copper base microcrystalline alloy is 1.5-3.5 μm.

16. Copper-based microcrystalline alloy according to any one of claims 1 to 3, wherein the copper-based microcrystalline alloy has a surface roughness Ra of 0.1 to 0.9.

17. Copper base microcrystalline alloy according to claim 16, wherein the surface roughness Ra of the copper base microcrystalline alloy is 0.2-0.5.

18. Copper base microcrystalline alloy according to claim 17, wherein the surface roughness Ra of the copper base microcrystalline alloy is 0.25-0.3.

19. A method for producing the copper-based microcrystalline alloy according to any one of claims 1 to 18, which comprises melting the alloy raw material, and then sequentially carrying out casting and cooling.

20. The method of claim 19, further comprising die casting the cooled alloy ingot.

21. The method of claim 20, wherein the die casting is semi-solid die casting.

22. An electronic product, characterized in that it comprises a structural part made of a material containing the copper-based microcrystalline alloy according to any one of claims 1 to 18.

23. The electronic product as claimed in claim 22, wherein the structural component is an appearance component.

24. The electronic product of claim 22, wherein the electronic product is a cell phone.

25. The electronic product of claim 22, wherein the structural component is a cell phone bezel.