A ZnO@CuO Reinforced Silver-Based Composite Material and Its Preparation Method

Abstract

The present invention discloses a ZnO@CuO reinforced silver-based composite material and a preparation method thereof, belonging to the technical field of new electronic information materials. The preparation method includes: mixing ZnO powder and copper powder and ball-milling to obtain ZnO@Cu powder; mixing the ZnO@Cu powder, silver powder, and silver oxide powder evenly, pressing them into an ingot blank, and then sintering to obtain a sintered blank of the ZnO@CuO reinforced silver-based composite material; finally, performing densification, extrusion drawing, or rolling on the sintered blank in sequence to prepare a wire or strip; the ball-milling speed is 400-800 r / min, the time is 0.5-3 h, and the atmosphere is an inert gas. The present invention uses a ball-milling method to prepare a core-shell structure ZnO@CuO to reinforce the silver-based material, utilizes the core-shell structure of ZnO@CuO to enhance the interfacial bonding force between the oxide and the Ag matrix, exerts the synergistic effect of the core-shell structure, and obtains a ZnO@CuO reinforced silver-based composite material with excellent mechanical properties and good electrical conductivity.

Description

Technical Field

[0001] The present invention belongs to the technical field of new electronic information materials, and particularly relates to a ZnO@CuO reinforced silver-based composite material and a preparation method thereof. Background Art

[0002] At the beginning, pure metal materials (such as Ag, Au, Pt) were used as electrical contact materials. Pure metal materials have good electrical conductivity and high thermal conductivity. With the industrial upgrade, due to the relatively low melting point of relevant pure metal electrical contacts, they cannot resist the heat release of the arc, resulting in the melting of the contact material and then causing welding failure. To solve this problem, noble metal-based composite materials came into being. Ag / CdO, as the earliest used electrical contact material, has quite excellent performance. However, the biggest problem with Ag / CdO materials is the presence of the toxic element Cd, which will generate Cd vapor during use and processing, and this gas will endanger human health.

[0003] At present, the preparation processes of silver metal oxide composite materials in the market include: powder pre-oxidation method and powder metallurgy method. The powder pre-oxidation method is a kind of powder metallurgy method. Due to many defects and the deterioration of the electrical contact performance of the material, it can no longer be used as the mainstream processing method. Powder metallurgy is the most basic and commonly used preparation process for silver metal oxide materials. Although it has the advantages of simple process and relatively easy addition of elements, the mixing process is very simple and it is easy to produce non-uniform existence of the reinforcing phase in the silver matrix. Moreover, the raw materials are easily contaminated by the outside world during the preparation process, resulting in more defects and the deterioration of the electrical contact performance of the material.

[0004] Based on the above industry background, there is an urgent need to explore a preparation technology for silver-based composite materials with a simple processing process and excellent product performance. Summary of the Invention

[0005] Aiming at the above-mentioned disadvantages of the prior art, the present invention provides a ZnO@CuO reinforced silver-based composite material and a preparation method thereof.

[0006] A preparation method of a ZnO@CuO reinforced silver-based composite material includes the following steps:

[0007] Mix ZnO powder and copper powder, and ball mill to obtain ZnO@Cu powder; then mix the ZnO@Cu powder with silver powder and silver oxide powder evenly, press them into an ingot blank and sinter to obtain a sintered blank of the ZnO@CuO reinforced silver-based composite material; finally, perform densification, extrusion drawing or rolling on the sintered blank in sequence to prepare wire or strip materials; the rotation speed of the ball milling is 400 - 800 r / min, the time is 0.5 - 3 h, and the ball milling atmosphere is an inert gas.

[0008] As a preferred embodiment of the present invention, the mass ratio of ZnO to copper powder is ZnO:Cu = 10:(0.5 - 3.5).

[0009] As a preferred embodiment of the present invention, the ZnO@Cu powder, silver powder, and silver oxide powder are formulated according to the mass percentage content of ZnO@CuO in the ZnO@CuO reinforced silver-based composite sintered blank being 10.5% - 14.5%.

[0010] As a preferred embodiment of the present invention, the ZnO@Cu powder, silver powder, and silver oxide powder are mixed evenly by ball milling. The rotation speed of the ball milling is 100 - 500 r / min, and the time is 0.5 - 2 h.

[0011] As a preferred embodiment of the present invention, the particle size of the ZnO powder is 40 - 80 nm, and the purity is 99.9%; the particle size of the copper powder is 0.5 - 50 µm, and the purity is 99.9%; the particle size of the silver powder is 10 - 80 µm, and the purity is 99.9%; the particle size of the silver oxide powder is 10 - 50 µm, and the purity is 99.9%.

[0012] As a preferred embodiment of the present invention, the sintering specifically involves heating the ingot blank to 100 - 200 °C and holding for 1 - 2 hours, then heating to 300 - 500 °C and holding for 1 - 2 hours, and finally holding at 830 - 850 °C for 0.5 - 3 hours.

[0013] As a preferred embodiment of the present invention, the pressure of the pressing is 150 - 500 MPa.

[0014] The present invention also claims to protect the ZnO@CuO reinforced silver-based composite material prepared by the preparation method of the ZnO@CuO reinforced silver-based composite material. The ZnO@CuO is a core-shell structure, with CuO as the shell and ZnO as the core.

[0015] The principle of the present invention lies in:

[0016] (1) The hardness of Cu in the present invention is lower than that of ZnO. During the ball milling process, Cu will undergo a welding phenomenon. Therefore, the core-shell structure ZnO@Cu is obtained, and then the ZnO@Cu is reacted with Ag and Ag2O by the in-situ reaction synthesis method to obtain the ZnO@CuO reinforced silver-based composite material.

[0017] (2) The present invention uses ZnO@CuO with a core-shell structure to reinforce the silver-based material, so that the conductivity and mechanical properties of the composite material are better. There are two main reasons: First, the shell CuO has good interface wettability with silver, which can improve the interface wettability of the ZnO-reinforced silver-based composite material, so that the interface between the reinforcing phase and silver is firmly bonded, and the processing performance and yield of the silver-based composite material are improved, thereby improving the mechanical properties of the ZnO@CuO-reinforced silver-based composite material. Second, the core-shell ZnO@CuO as a reinforcing phase can ensure the uniformity of the distribution of the reinforcing phase in the silver matrix and give full play to the barrier effect of the reinforcing phase on dislocation, thereby improving the mechanical properties of the ZnO@CuO-reinforced silver-based composite material and the electrical corrosion stability during the electrical contact application process.

[0018] Compared with the prior art, the present invention has the following beneficial effects: the present invention adopts a ball milling method to prepare a core-shell structured ZnO@CuO to reinforce the silver-based material, utilizes the core-shell structure of ZnO@CuO to enhance the interfacial bonding force between the oxide reinforcement phase and the Ag matrix, and exerts the synergistic effect of the core-shell structure to obtain a ZnO@CuO reinforced silver-based composite material with excellent mechanical properties while the conductive properties remain basically unchanged. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a flow chart of the preparation process of the ZnO@CuO reinforced silver-based composite material of the present invention.

[0020] Figure 2 This is a metallographic diagram of the ZnO@CuO reinforced silver-based composite material prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0021] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0022] The particle size of the ZnO powder used in Examples 1-4 and Comparative Examples 1-4 is 40-80 nm, and the purity is 99.9%; the particle size of the copper powder is 0.5-50µm, and the purity is 99.9%; the particle size of the silver powder is 10-80µm, and the purity is 99.9%; the particle size of the silver oxide powder is 10-50µm, and the purity is 99.9%.

[0023] Example 1

[0024] A method for preparing a ZnO@CuO reinforced silver-based composite material comprises the following steps:

[0025] (1) Mix ZnO powder and copper powder according to a mass ratio of ZnO:Cu = 10:1.5, and then under argon protection, ball mill at a rotation speed of 500 r / min for 1.5 h to obtain ZnO@Cu powder; then configure the ZnO@Cu powder, silver powder, and silver oxide powder according to the formation of ZnO@CuO with a mass percentage of 14.7% in the silver matrix, and ball mill at a rotation speed of 300 r / min for 1 h to obtain a uniformly mixed material;

[0026] (2) Press into an ingot blank under a pressure condition of 350 MPa, and sinter the ingot blank according to the sintering process of holding at 100 °C for 1 h → holding at 300 °C for 1 h → holding at 830 °C for 1 h to obtain a sintered blank of ZnO@CuO reinforced silver-based composite material;

[0027] (3) Successively perform densification, extrusion drawing or rolling on the sintered blank to prepare a wire.

[0028] The tensile strength of the prepared ZnO@CuO reinforced silver-based composite material wire is 360 MPa.

[0029] Example 2

[0030] A preparation method of ZnO@CuO reinforced silver-based composite material, comprising the following steps:

[0031] (1) Mix ZnO powder and copper powder according to a mass ratio of ZnO:Cu = 10:0.5, and then under argon protection, ball mill at a rotation speed of 400 r / min for 3 h to obtain ZnO@Cu powder; then configure the ZnO@Cu powder, silver powder, and silver oxide powder according to the formation of ZnO@CuO with a mass percentage of 10.5% in the silver matrix, and ball mill at a rotation speed of 200 r / min for 2 h to obtain a uniformly mixed material;

[0032] (2) Press into an ingot blank under a pressure condition of 500 MPa, and sinter the ingot blank according to the sintering process of holding at 150 °C for 1 h → holding at 360 °C for 1 h → holding at 840 °C for 1 h to obtain a sintered blank of ZnO@CuO reinforced silver-based composite material;

[0033] (3) Successively perform densification, extrusion drawing or rolling on the sintered blank to prepare a wire.

[0034] The tensile strength of the prepared ZnO@CuO reinforced silver-based composite material wire is 352 MPa.

[0035] Example 3

[0036] A preparation method of ZnO@CuO reinforced silver-based composite material, comprising the following steps:

[0037] (1) Mix ZnO powder and copper powder according to the mass ratio of ZnO:Cu = 10:3.5, and then under argon protection, ball mill for 0.5 h at a rotation speed of 800 r / min to obtain ZnO@Cu powder; then configure the ZnO@Cu powder, silver powder, and silver oxide powder according to the standard of generating 14% by mass of ZnO@CuO in the silver matrix, and ball mill for 0.5 h at a rotation speed of 500 r / min to obtain a uniformly mixed material;

[0038] (2) Press into an ingot blank under a pressure condition of 500 MPa, and sinter the ingot blank according to the sintering process of holding at 200 °C for 2 h → holding at 500 °C for 1 h → holding at 850 °C for 0.5 h to obtain a sintered blank of ZnO@CuO reinforced silver-based composite material;

[0039] (3) Perform densification, extrusion drawing or rolling on the sintered blank in sequence to prepare a wire.

[0040] The tensile strength of the prepared ZnO@CuO reinforced silver-based composite material wire is 358 MPa.

[0041] Example 4

[0042] A preparation method of ZnO@CuO reinforced silver-based composite material, comprising the following steps:

[0043] (1) Mix ZnO powder and copper powder according to the mass ratio of ZnO:Cu = 10:2.5, and then under argon protection, ball mill for 3 h at a rotation speed of 600 r / min to obtain ZnO@Cu powder; then configure the ZnO@Cu powder, silver powder, and silver oxide powder according to the standard of generating 13.5% by mass of ZnO@CuO in the silver matrix, and ball mill for 1 h at a rotation speed of 400 r / min to obtain a uniformly mixed material;

[0044] (2) Press into an ingot blank under a pressure condition of 500 MPa, and sinter the ingot blank according to the sintering process of holding at 100 °C for 2 h → holding at 380 °C for 1 h → holding at 830 °C for 3 h to obtain a sintered blank of ZnO@CuO reinforced silver-based composite material;

[0045] (3) Perform densification, extrusion drawing or rolling on the sintered blank in sequence to prepare a wire.

[0046] The tensile strength of the prepared ZnO@CuO reinforced silver-based composite material wire is 356 MPa.

[0047] Comparative Example 1

[0048] A preparation method of ZnO / CuO reinforced silver-based composite material, comprising the following steps:

[0049] (1) Mix ZnO powder and copper powder in a mass ratio of ZnO:Cu = 10:1.5 to form a mixed powder. Then, configure the mixed powder with silver powder and silver oxide powder based on generating ZnO@CuO with a mass percentage of 14.7% in the silver matrix, and mix them evenly.

[0050] (2) Press into an ingot blank under a pressure condition of 350 MPa, and sinter the ingot blank according to the sintering process of holding at 100 °C for 1 h → holding at 300 °C for 1 h → holding at 830 °C for 1 h to obtain a sintered blank of ZnO / CuO reinforced silver-based composite material.

[0051] (3) Successively perform densification, extrusion drawing or rolling on the sintered blank to prepare a wire.

[0052] The tensile strength of the prepared ZnO / CuO reinforced silver-based composite material wire is 300 MPa.

[0053] Comparative Example 2

[0054] A preparation method of a CuO reinforced silver-based composite material includes the following steps:

[0055] (1) Configure copper powder with silver powder and silver oxide powder based on generating CuO with a mass percentage of 14.7% in the silver matrix, and ball mill for 1 h at a rotation speed of 300 r / min to obtain a uniformly mixed material.

[0056] (2) Press into an ingot blank under a pressure condition of 350 MPa, and sinter the ingot blank according to the sintering process of holding at 100 °C for 1 h → holding at 300 °C for 1 h → holding at 830 °C for 1 h to obtain a sintered blank of CuO reinforced silver-based composite material.

[0057] (3) Successively perform densification, extrusion drawing or rolling on the sintered blank to prepare a wire.

[0058] The tensile strength of the prepared CuO reinforced silver-based composite material wire is 290 MPa.

[0059] Comparative Example 3

[0060] A preparation method of a ZnO reinforced silver-based composite material includes the following steps:

[0061] (1) Configure ZnO powder with silver powder and silver oxide powder based on generating ZnO with a mass percentage of 14.7% in the silver matrix, and ball mill for 1 h at a rotation speed of 300 r / min to obtain a uniformly mixed material.

[0062] (2) Press into an ingot blank under a pressure condition of 350 MPa, and sinter the ingot blank according to a sintering process of holding at 100 °C for 1 h → holding at 300 °C for 1 h → holding at 830 °C for 1 h to obtain a sintered blank of ZnO-reinforced silver-based composite material;

[0063] (3) Carry out densification, extrusion drawing or rolling on the sintered blank in sequence to prepare a wire.

[0064] The tensile strength of the prepared ZnO-reinforced silver-based composite material wire is 290 MPa.

[0065] Comparative Example 4

[0066] A preparation method of ZnO@CuO-reinforced silver-based composite material, comprising the following steps:

[0067] (1) Mix ZnO powder and copper powder according to a mass ratio of ZnO:Cu = 10:1.5, then under argon protection, ball mill at a rotation speed of 500 r / min for 1.5 h to obtain ZnO@Cu powder; then configure the ZnO@Cu powder, silver powder and silver oxide powder according to the standard of generating ZnO@CuO with a mass percentage content of 14.7% in the silver matrix, and ball mill at a rotation speed of 300 r / min for 1 h to obtain uniform mixing;

[0068] (2) Press into an ingot blank under a pressure condition of 350 MPa, and hold the ingot blank at 830 °C for 3 h to obtain a sintered blank of ZnO@CuO-reinforced silver-based composite material;

[0069] (3) Carry out densification, extrusion drawing or rolling on the sintered blank in sequence to prepare a wire.

[0070] The tensile strength of the prepared ZnO@CuO-reinforced silver-based composite material wire is 310 MPa.

[0071] Comparative Example 5

[0072] A preparation method of ZnO@CuO-reinforced silver-based composite material, comprising the following steps:

[0073] (1) Mix ZnO powder and copper powder according to a mass ratio of ZnO:Cu = 10:1.5, then in air, ball mill at a rotation speed of 500 r / min for 1.5 h to obtain ZnO@CuO powder; then configure the ZnO@CuO powder, silver powder and silver oxide powder according to the standard of generating ZnO@CuO with a mass percentage content of 14.7% in the silver matrix, and ball mill at a rotation speed of 300 r / min for 1 h to obtain uniform mixing;

[0074] (2) Press into ingots under the pressure condition of 350 MPa, and sinter the ingots according to the sintering process of keeping warm at 100 °C for 1 h → keeping warm at 300 °C for 1 h → keeping warm at 830 °C for 1 h to obtain a sintered blank of ZnO@CuO reinforced silver-based composite material;

[0075] (3) Successively carry out densification, extrusion drawing or rolling on the sintered blank to prepare it into a wire.

[0076] The tensile strength of the ZnO@CuO reinforced silver-based composite material wire prepared is 331 MPa.

[0077] Comparative Example 6

[0078] The only difference between the preparation method of the ZnO@CuO reinforced silver-based composite material and Example 1 is that the particle size of the ZnO powder used is 200 - 300 nm.

[0079] The tensile strength of the ZnO@CuO reinforced silver-based composite material wire prepared is 302 MPa.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A preparation method of ZnO@CuO enhanced silver-based composite material, characterized in that, It includes the following steps: Mix ZnO powder and copper powder and ball-mill them to obtain ZnO@Cu powder; the rotation speed of the ball-milling is 400 - 800 r / min, the time is 0.5 - 3 h, and the ball-milling atmosphere is an inert gas; Then mix the ZnO@Cu powder, silver powder, and silver oxide powder evenly by ball-milling, press them into an ingot blank and then sinter them. The rotation speed of the ball-milling is 100 - 500 r / min, and the time is 0.5 - 2 h; obtain a sintered blank of ZnO@CuO-reinforced silver-based composite material; Finally, densify the sintered blank, and then extrude, draw, or roll it to prepare a wire or strip; The sintering is specifically to heat the ingot blank to 100 - 200 °C and keep it warm for 1 - 2 hours, then heat it to 300 - 500 °C and keep it warm for 1 - 2 hours, and finally keep it warm at 830 - 850 °C for 0.5 - 3 hours; The mass ratio of ZnO to copper powder is ZnO:Cu = 10:(0.5 - 3.5); The ZnO@Cu powder, silver powder, and silver oxide powder are formulated according to the mass percentage content of ZnO@CuO in the sintered blank of ZnO@CuO-reinforced silver-based composite material being 10.5% - 14.5%; The particle size of the ZnO powder is 40 - 80 nm, the particle size of the copper powder is 0.5 - 50 µm, the particle size of the silver powder is 10 - 80 µm, and the particle size of the silver oxide powder is 10 - 50 µm.

2. The preparation method of the ZnO@CuO enhanced silver-based composite material according to claim 1, characterized in that, The purity of the ZnO powder is 99.9%; the purity of the copper powder is 99.9%; the purity of the silver powder is 99.9%; the purity of the silver oxide powder is 99.9%.

3. The preparation method of the ZnO@CuO enhanced silver-based composite material according to claim 1, characterized in that, The pressure of the pressing is 150 - 500 MPa.

4. The ZnO@CuO reinforced silver-based composite material prepared by the preparation method of the ZnO@CuO reinforced silver-based composite material according to any one of claims 1-3, characterized in that, The ZnO@CuO has a core-shell structure, with CuO as the shell and ZnO as the core.

Images