Method for regulating and controlling dispersed phase in copper-based composite material by using metal Ti

Abstract

The invention discloses a method for regulating and controlling a dispersed phase in a copper-based composite material through metal Ti, and relates to the technical field of metal-based composite material preparation. The preparation raw materials comprise metal Cu powder, metal Y powder and metal Ti, air serves as an oxidizing agent, fine and evenly-distributed dispersed phases are formed in situ in the mechanical alloying process, and the metal oxide particle dispersion strengthened copper powder is prepared. And then the high-density and high-performance metal oxide particle dispersion strengthened copper-based composite material is obtained through hot pressing sintering densification. In the preparation process, the metal Y is subjected to an in-situ reaction to produce Y2O3, the existence of the metal Ti can inhibit irregular growth of Y2O3, the size of a dispersed phase is remarkably reduced, and a clean interface between the dispersed phase and a matrix is ensured. Through the method, the mechanical property of the composite material can be remarkably improved. The production mode not only improves the production efficiency, but also reduces the production cost.

Description

Technical Field

[0001] The present invention relates to the technical field of preparation of metal matrix composites, and particularly to a method for regulating dispersed phases in copper matrix composites by using metal Ti. Background Art

[0002] Oxide dispersion strengthened copper is a technology that enhances the performance of copper materials by introducing nano-scale oxide particles into the copper matrix. These oxide particles can effectively pin dislocations, inhibit dislocation movement and grain boundary slip, thereby significantly enhancing the mechanical properties of copper materials. The key to the dispersion strengthening effect lies in the particle size and uniform distribution of the dispersed phase. The smaller the particle size and the more uniform the distribution, the more significant the strengthening effect. Existing preparation techniques include internal oxidation method, mechanical alloying method, solid-liquid doping method, solution-gel method, etc.

[0003] Oxide dispersion strengthened copper alloys have multiple advantages: such as high-temperature strength and hardness, excellent oxidation resistance, outstanding electrical and thermal conductivity, excellent wear resistance, and relatively high anti-softening temperature. Specifically, oxide dispersion strengthened copper alloys can maintain good mechanical properties in high-temperature environments and have strong antioxidant capabilities, reducing oxidation losses at high temperatures. In high-temperature and high-friction application environments, such as resistance welding electrodes, their wear resistance is also particularly outstanding. In addition, the dispersed alumina particles can effectively prevent interdiffusion between metals, especially in the application of resistance welding electrodes, significantly reducing electrode wear.

[0004] In existing methods for preparing oxide dispersion strengthened copper alloys, the internal oxidation method and the mechanical alloying method have limitations in refining the particle size of the dispersed phase and are prone to agglomeration of the dispersed phase particles. The solid-liquid doping method and the solution-gel method can achieve uniform distribution of the dispersed phase, but the processes are relatively complex, the cost is high, and they are not suitable for large-scale production. The internal oxidation method uses the oxygen-selective oxidation of yttrium in a low-oxygen environment of Cu-Y alloy to generate Y2O3. Although this method is widely used, its process is complex, the equipment is expensive, and the production efficiency is low. The mechanical alloying method makes atoms in the powder particles diffuse through repeated cold welding and fracture by high-energy ball milling. However, the high plasticity of copper powder makes the dispersed phase prone to agglomeration during ball milling.

[0005] In order to simplify the preparation process and improve the performance of copper materials, the present invention proposes to introduce Ti metal as a third phase to strengthen oxide dispersion strengthened copper. This method can not only significantly improve the mechanical properties of the material but also meet the requirements of large-scale production. Compared with the traditional mechanical alloying process, adding Ti metal can precisely control the particle size of the dispersed phase, providing incomparable advantages, making the performance of the final product higher, and significantly improving the production efficiency and economic benefits. Summary of the Invention

[0006] The present invention provides a method for regulating the dispersed phase in a copper-based composite material by using metal Ti. The core of this method lies in using metal Ti to regulate the size of the dispersed phase and in-situ generating oxide dispersed phases during the mechanical alloying process. Compared with traditional processes, the present invention has significant advantages in the generation and distribution of the dispersed phase. During mechanical alloying, metal Y reacts with oxygen in the air to in-situ generate oxide dispersed phases. These in-situ generated oxide dispersed phase particles are finer and more uniformly distributed, forming a semi-coherent interface between the strengthening phase and the matrix phase, with a clean and high-strength interface. By this method, the mechanical properties of the material can be significantly improved. This production method not only improves production efficiency but also reduces production costs, making the industrial production of dispersion-strengthened copper-based composite materials possible. The in-situ generated dispersed phase particles can effectively pin dislocations, prevent dislocation movement and grain boundary slip, thereby significantly enhancing the strength and hardness of copper materials. The presence of Ti metal inhibits the irregular growth of oxides, significantly reduces the size of the dispersed phase, ensures a clean interface between the dispersed phase and the matrix, and further improves the comprehensive properties of the material.

[0007] For the above purpose, the technical solution adopted by the present invention is as follows:

[0008] A method for regulating the dispersed phase in a copper-based composite material by using metal Ti, the preparation raw materials include metal Cu powder, metal Y powder and metal Ti, using air as an oxidant, and in-situ forming fine and uniformly distributed dispersed phases during the mechanical alloying process to obtain metal oxide particle dispersion-strengthened copper powder; then obtaining a high-density and high-performance metal oxide particle dispersion-strengthened copper-based composite material through hot press sintering densification.

[0009] As a preferred technical solution of the present invention, the preparation method specifically includes the following steps:

[0010] Step 1: Prepare metal oxide particle dispersion-strengthened copper powder by mechanical alloying

[0011] Add Cu powder, metal Y powder and metal Ti powder into a cemented carbide ball milling tank; add cemented carbide grinding balls and alcohol, and then place the tank body into a high-energy ball mill for ball milling to obtain metal oxide particle dispersion-strengthened copper powder;

[0012] Step 2: Reduction of metal oxide particle dispersion-strengthened copper powder

[0013] Calcine and reduce the metal oxide particle dispersion-strengthened copper powder obtained in Step 1 in a hydrogen atmosphere to obtain pure metal oxide particle dispersion-strengthened copper powder;

[0014] Step 3: Sintering densification of metal oxide particle dispersion-strengthened copper-based composite material

[0015] The metal oxide particle dispersion strengthened copper powder prepared in step 2 is subjected to hot press sintering densification to finally obtain a metal oxide particle composite dispersion strengthened copper matrix composite material.

[0016] As a further preferred technical solution of the present invention, in the preparation method:

[0017] In step 1, the molar ratio of the addition amounts of metal Ti and metal Y is 0.28 - 0.56:1. The ball milling parameters are as follows: the diameter of the grinding balls is 4 mm, the ball-to-powder ratio is 6 - 8:2 - 4, the rotation speed is 300 - 800 rpm, and the ball milling time is 12 - 48 h.

[0018] In step 2, the parameters of calcination reduction are as follows: the used atmosphere is an Ar - H2 mixed gas with 10% H2 content, the heating rate is 5 °C / min, the calcination temperature is 400 - 600 °C, and the heat preservation time is 2 h.

[0019] The specific steps in step 3 are as follows: The metal oxide particle dispersion strengthened copper powder is pressed into a green compact with a diameter of Ф15 mm and a thickness of 1 - 2 cm. The green compact sample is placed into a hot press mold, and sintering is carried out under an atmosphere of nitrogen gas being introduced. An axial pressure is applied to the sample using a pressurizing device, the pressure is 20 MPa, the temperature is raised to 900 °C, the heating rate is 3 - 5 °C / min, and it is kept at a constant temperature for 6 h. After the sample undergoes constant temperature heat preservation, it is cooled down and the pressure is unloaded, and it is cooled down to room temperature along with the furnace, finally obtaining a metal oxide particle dispersion strengthened copper matrix composite material.

[0020] In the process of preparing the metal oxide particle dispersion strengthened copper matrix composite material of the present invention, in the ball milling process, metal Y undergoes an in-situ reaction to produce Y2O3. The presence of Ti metal can inhibit the irregular growth of Y2O3, significantly reduce the size of the dispersion phase, and ensure a clean interface between the dispersion phase and the matrix. Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] (1) Compared with the hot isostatic pressing sintering method, the hot pressing method used in the present invention simplifies the sintering process, has low requirements for equipment, is simple in process, the sintering is successful in one step, shortens the preparation cycle, and reduces the preparation cost. Moreover, in the present invention, by controlling the atmosphere, pressurizing time, heating rate, and sintering temperature, high-quality ODS copper matrix composite materials are precisely sintered.

[0022] (2) The Ti element introduced in the present invention can effectively inhibit the growth of irregular oxide particles and the formation of the oxidation zone, and can also inhibit the shape and size of the oxides, making them more fragmented and finer, thereby reducing the size of the metal oxide particles. Compared with the metal oxide dispersion strengthened copper prepared by the ball milling method, by directly adding the Ti element, the preparation cost and time can be reduced.

[0023] (3) The Ti element introduced in the present invention can not only regulate the formation of metal oxides, but also increase the content of metal oxide dispersion phases in the copper-based composite materials. The microhardness and mechanical properties of the Ti element introduced in the present invention are generally higher than those of the specimens without Ti doping. Description of the Drawings

[0024] Figure 1 Comparison of the tensile curves of the composite materials prepared in different embodiments.

[0025] Figure 2 SEM and EDS images of the fracture surface of the composite material prepared in Example 1.

[0026] Figure 3 SEM and EDS images of the fracture surface of the composite material prepared in Example 2.

[0027] Figure 4 SEM and EDS images of the fracture surface of the composite material prepared in Comparative Example 1. Detailed Embodiments

[0028] The following elaborates in detail on the preferred embodiments and comparative embodiments of the present invention, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making the protection scope of the present invention more clearly defined.

[0029] A method for regulating dispersion phases in copper-based composite materials using metal Ti proposed by the present invention. By adding metal yttrium and using in-situ reaction, metal Ti is used as the third phase to regulate the formation of dispersion phases. During the ball milling process, fine and uniformly distributed metal oxide dispersion phases are formed, and finally, a high-density and high-performance metal oxide particle dispersion-strengthened copper-based composite material is obtained through hot pressing sintering densification.

[0030] Example 1

[0031] In this embodiment, an oxide dispersion-strengthened copper-based composite material was prepared using a mechanical alloying process and a hot pressing sintering method. When preparing the copper-based composite material, the molar ratio of Ti to Y was controlled to be 0.28:1.

[0032] The method for preparing the dispersion-strengthened copper-based composite material in this embodiment is as follows:

[0033] Step 1, preparation of oxide dispersion-strengthened copper powder: After mixing 98.18 g of copper powder, 0.6 g of metal Y powder, and 0.31 g of metal Ti powder, they were placed in a cemented carbide ball milling tank, and cemented carbide grinding balls and alcohol were added to keep the ball-to-powder ratio at 3:1. Then the tank body was sealed and placed in a high-energy ball mill, and ball milling was carried out at a rotation speed of 500 rpm for 12 h.

[0034] Step 2, reduction treatment of oxide dispersion strengthened copper powder: The powder obtained in Step 1 is placed in an Ar-H2 mixed atmosphere (H2 content is 10%) for calcination reduction. First, ventilate for 20 min at room temperature to remove air, then heat up to 400 °C at a heating rate of 5 °C / min, hold for 2 h, and finally obtain pure oxide dispersion strengthened copper powder.

[0035] Step 3, sintering densification: The obtained pure powder is pressed into a green compact with a diameter of 15 mm and a thickness of 2 cm. The green compact sample is placed in a hot pressing mold and sintered in a nitrogen atmosphere. Apply an axial pressure of 20 MPa through a pressurizing device, heat up to 900 °C at a heating rate of 5 °C / min, and hold for 6 h. After sintering, cool the sample to room temperature with the furnace and relieve the pressure, and finally obtain a metal oxide particle dispersion strengthened copper matrix composite.

[0036] Example 2

[0037] In this example, an oxide dispersion strengthened copper matrix composite was prepared by mechanical alloying process and hot pressing sintering method. When preparing the copper matrix composite, the molar ratio of Ti to Y was controlled to be 0.56:1.

[0038] The method for preparing the dispersion strengthened copper matrix composite in this example is as follows:

[0039] Step 1, preparation of oxide dispersion strengthened copper powder: After mixing 99.34 g of copper powder, 0.6 g of metal Y powder and 0.06 g of metal Ti powder, put them into a cemented carbide ball milling tank, add cemented carbide grinding balls and alcohol, and keep the ball-powder ratio at 3:1. Then seal the tank body and put it into a high-energy ball mill, and carry out ball milling at a rotation speed of 500 rpm for 12 h.

[0040] Step 2, reduction treatment of oxide dispersion strengthened copper powder: The powder obtained in Step 1 is placed in an Ar-H2 mixed atmosphere (H2 content is 10%) for calcination reduction. First, ventilate for 20 min at room temperature to remove air, then heat up to 400 °C at a heating rate of 5 °C / min, hold for 2 h, and finally obtain pure oxide dispersion strengthened copper powder.

[0041] Step 3, sintering densification: The obtained pure powder is pressed into a green compact with a diameter of 15 mm and a thickness of 2 cm. The green compact sample is placed in a hot pressing mold and sintered in a nitrogen atmosphere. Apply an axial pressure of 20 MPa through a pressurizing device, heat up to 900 °C at a heating rate of 5 °C / min, and hold for 6 h. After sintering, cool the sample to room temperature with the furnace and relieve the pressure, and finally obtain a metal oxide particle dispersion strengthened copper matrix composite.

[0042] Comparative Example 1

[0043] In this example, the oxide dispersion strengthened copper matrix composite material is prepared by mechanical alloying process and hot pressing sintering to prepare a dispersion strengthened copper matrix composite material (Y content is 1 wt%).

[0044] The method for preparing the dispersion strengthened copper matrix composite material in this comparative example is as follows:

[0045] Step 1, preparation of oxide dispersion strengthened copper powder: After mixing 99.4 g of copper powder and 0.6 g of metal Y powder, put them into a cemented carbide ball milling tank, add cemented carbide grinding balls and alcohol, and keep the ball-to-powder ratio at 3:1. Then seal the tank body and put it into a high-energy ball mill, and carry out ball milling at a rotation speed of 500 rpm for 12 h.

[0046] Step 2, reduction treatment of oxide dispersion strengthened copper powder: Place the powder obtained in Step 1 in an Ar-H2 mixed atmosphere (H2 content is 10%) for calcination reduction. First, ventilate for 20 min at room temperature to remove air, then heat up to 400 °C at a heating rate of 5 °C / min, keep the temperature for 2 h, and finally obtain pure oxide dispersion strengthened copper powder.

[0047] Step 3, sintering densification: Press the obtained pure powder into a green compact with a diameter of 15 mm and a thickness of 2 cm, put the green compact sample into a hot pressing die, and carry out sintering in a nitrogen atmosphere. Apply an axial pressure of 20 MPa through a pressurizing device, heat up to 900 °C at a heating rate of 5 °C / min, and keep the temperature for 6 h. After sintering, cool the sample to room temperature with the furnace and relieve the pressure, and finally obtain a metal oxide particle dispersion strengthened copper matrix composite material.

[0048] Through Figure 1 It can be seen that the dispersion strengthened copper matrix composite material prepared by adding metal Ti has higher tensile strength than the Y2O3 dispersion strengthened copper matrix composite material directly obtained by adding metal yttrium, the strength is increased by 10%, and it has better plasticity.

[0049] Through Figures 2 to 4 By comparing the fracture surfaces, it can be observed that there are a large number of agglomerations of dispersed phases at the fracture surface of directly adding metal yttrium, while the Y2O3 of the sample adding metal Ti has a uniform dispersion effect. For the copper matrix composite material prepared by adding metal Ti, the fracture mode of Example 1 is ductile fracture, the fracture surface contains a large number of dimples, and the dispersion of oxide particles is relatively uniform, indicating that the size of oxide particles can be regulated after adding metal Ti, the agglomeration of oxides can be inhibited, and the strength of the copper matrix is improved.

[0050] In summary, through the hot pressing sintering process combined with Ti metal as the third phase to regulate the formation of oxides, the present invention has successfully achieved the large-scale production of high-performance dispersion strengthened copper. This method significantly improves the mechanical, electrical conductivity and antioxidant properties of copper materials, providing a simple and efficient solution for the industrial production of dispersion strengthened copper materials.

[0051] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of the present technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, as long as they do not deviate from the concept of the invention or exceed the scope defined by this claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for regulating dispersed phases in a copper-based composite material by using metal Ti, characterized in that The raw materials for preparation include metallic Cu powder, metallic Y powder and metallic Ti. Using air as the oxidant and through the in-situ formation of fine and uniformly distributed dispersion phases during mechanical alloying, metal oxide particle dispersion strengthened copper powder is obtained. Then, through hot pressing sintering densification, a high-density and high-performance metal oxide particle dispersion strengthened copper matrix composite material is obtained.

2. The method according to claim 1, characterized in that Specifically, it includes the following steps: Step 1: Prepare metal oxide particle dispersion strengthened copper powder by mechanical alloying Add Cu powder, metallic Y powder and metallic Ti powder into a cemented carbide ball milling tank; add cemented carbide grinding balls and alcohol, and then place the tank body into a high-energy ball mill for ball milling to obtain metal oxide particle dispersion strengthened copper powder; Step 2: Reduce the metal oxide particle dispersion strengthened copper powder Carry out calcination reduction of the metal oxide particle dispersion strengthened copper powder obtained in Step 1 in a hydrogen atmosphere to obtain pure metal oxide particle dispersion strengthened copper powder; Step 3: Sintering densification of the metal oxide particle dispersion strengthened copper matrix composite material Carry out hot pressing sintering densification on the metal oxide particle dispersion strengthened copper powder prepared in Step 2 to finally obtain a metal oxide particle multi-phase dispersion strengthened copper matrix composite material.

3. The method according to claim 2, wherein In Step 1, the molar ratio of the addition amounts of metallic Ti and metallic Y is 0.28 - 0.56:

1.

4. The method according to claim 2, wherein The ball milling parameters in Step 1 are: the diameter of the grinding balls is 4 mm, the ball-to-powder ratio is 6 - 8:2 - 4, the rotation speed is 300 - 800 rpm, and the ball milling time is 12 - 48 h.

5. The method according to claim 2, wherein The parameters for calcination reduction in Step 2 are: the used atmosphere is an Ar-H2 mixed gas with 10% H2 content, the heating rate is 5 °C / min, the calcination temperature is 400 - 600 °C, and the holding time is 2 h.

6. The method according to claim 2, wherein The specific steps in Step 3 are: Press the metal oxide particle dispersion strengthened copper powder into a green compact with a diameter of Ф15 mm and a thickness of 1 - 2 cm. Place the green compact sample into a hot pressing mold, and carry out sintering in an atmosphere with nitrogen gas introduced. Use a pressing device to apply an axial pressure of 20 MPa to the sample, heat up to 900 °C at a heating rate of 3 - 5 °C / min, hold for 6 h. After the sample is held at a constant temperature, cool down and unload the pressure, and cool down to room temperature with the furnace to finally obtain a metal oxide particle dispersion strengthened copper matrix composite material.

7. The metal oxide particle dispersion strengthened copper-based composite material prepared by the method according to any one of claims 1 to 6, characterized in that, During the ball milling process, metallic Y undergoes an in-situ reaction to produce Y2O3. The presence of Ti metal can inhibit the irregular growth of Y2O3, significantly reduce the size of the dispersion phase, and ensure a clean interface between the dispersion phase and the matrix.

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