CN116005027A - A method for preparing copper-based composite materials by combining atomization and mechanical alloying - Google Patents

Abstract

A method for preparing copper-based composite materials by combining atomization and mechanical alloying, which relates to the field of preparation of copper-based composite materials. Firstly, through vacuum high-temperature smelting and atomization treatment, dispersed-phase element persolid solution Cu-based composite atomized powder is prepared, and then It and deionized water as a process control agent and oxidant are prepared by a mechanical alloying process under the protection of an inert atmosphere to prepare precursor powders, followed by drying to remove the lubricating film formed by deionized water on the surface of the precursor powders, and finally The copper matrix composite material is obtained by calcination reduction and vacuum hot pressing sintering. The preparation process of the present invention combines smelting, rapid atomization, mechanical alloying and vacuum hot-pressing sintering processes to overcome the element segregation in the traditional internal oxidation process and the phenomenon of dispersed phase enrichment in the shell layer; the traditional internal oxidation process requires dispersed phase elements In the Cu matrix, it is necessary to have a certain solid solubility limit, broaden the types of dispersed phases, and realize the high-strength and high-conductivity characteristics of copper-based composite materials.

Description

A method for preparing copper-based composite materials by combining atomization and mechanical alloying

technical field

The invention relates to the field of preparation of copper-based composite materials, in particular to a method for preparing copper-based composite materials by combining atomization and mechanical alloying.

Background technique

Dispersion-strengthened copper-based composites greatly improve the high-temperature mechanical properties of the material without seriously affecting the electrical and thermal conductivity of the material. In addition, compared with processes such as work hardening and age strengthening, dispersion strengthened copper has excellent high temperature thermal stability. Therefore, dispersion-strengthened copper-based composite materials have very broad application prospects in many extreme environments, such as lead frames of integrated circuits, electrical contact materials, self-cooling and heat-conducting materials such as high-power electronic tube brackets, etc.

At present, the main methods for preparing dispersion-strengthened copper are internal oxidation process and mechanical alloying process. Among them, the mechanical alloying process will inevitably introduce impurities, and the large-scale promotion is limited, so the commercialization process is insufficient. At present, the relatively mature process is the internal oxidation process route, which is used for large-scale preparation of commercial dispersion-strengthened copper-based composite material Glidcop (Al ₂ O ₃ dispersion-strengthened copper). The preparation process is as follows: firstly, the Cu-based powder containing Al element is melted, and then it is atomized to prepare Cu-based powder containing Al element, and then the powder is subjected to high-temperature in-situ oxidation operation to generate Al ₂ O ₃ dispersed phase, followed by high-temperature reduction sintering to obtain Al ₂ O ₃ dispersion-strengthened copper composites.

However, the high-temperature internal oxidation process is complex and requires strict parameters. It is the core step in the commercial preparation process and requires precise control of the oxygen partial pressure to achieve the purpose of selectively in-situ oxidation of Al in Cu-based powders. This puts strict restrictions on the type and content of the dispersed phase. First, the dispersed phase elements must have a certain solid solubility in the Cu matrix under high temperature conditions to avoid the precipitation and aggregation of the dispersed phase elements under high temperature conditions; secondly, The content of the dispersed phase elements should not be too high, so as to prevent the elements from diffusing to the surface in the Cu-based powder particles and form an enriched dispersed-phase shell, which will lead to uneven distribution of the components of the dispersion-strengthened copper-based composite material, dispersion-phase aggregation, and comprehensive performance. decline.

Therefore, in view of the above situation, it is of great significance to develop new preparation methods to avoid segregation of dispersed phase elements, enrich the shell of dispersed phase, and broaden the types of dispersed phases for the development of high-performance copper matrix composites.

Contents of the invention

In order to improve the segregation of elements in the traditional internal oxidation process, the phenomenon of enrichment of the dispersed phase in the shell; the traditional internal oxidation process requires that the dispersed phase elements must have a certain solid solubility in the Cu matrix, broaden the types of the dispersed phase, and realize the copper-based High-strength and high-conductivity properties of composite materials. The invention proposes a method for preparing copper-based composite materials by combining atomization and mechanical alloying, which can prepare dispersion-strengthened copper-based composite materials with fine dispersed phase particles, high number density, uniform element distribution and excellent comprehensive performance.

In order to realize the above-mentioned purpose of the invention, the technical scheme adopted in the present invention is:

A method for preparing copper-based composite materials by combining atomization and mechanical alloying, firstly preparing dispersed phase element Y or Al through solid solution Cu-based composite atomized powder Cu-Y or Cu-Al through vacuum high-temperature melting and atomization treatment, Then prepare the precursor powder with deionized water as a process control agent and oxidant under the protection of an inert atmosphere through a mechanical alloying process, and then dry to remove the lubricating film formed by the deionized water on the surface of the precursor powder, Finally, the copper-based composite material Cu-Y ₂ O ₃ or Cu-Al ₂ O ₃ is obtained by calcining reduction and vacuum hot-pressing sintering in sequence.

The specific steps of the preparation method are as follows:

① High-temperature melting: Put copper ingots and yttrium ingots or copper ingots and aluminum ingots in the vacuum melting furnace of the gas atomization furnace for melting, and then pour the molten metal from the melting furnace into the tundish crucible under vacuum conditions. insulation;

②Preparation of spheroidized alloy powder by gas atomization: After heat preservation, the casting liquid is introduced into a high-pressure gas atomizer, collected by a cyclone separator, and sieved to obtain dispersed phase element Y or Al persolution Cu-based composite mist with different particle sizes Powdered Cu-Y or Cu-Al;

③Mechanical alloying: put the above-mentioned dispersed phase element Y or Al persolid solution Cu-based composite atomized powder Cu-Y or Cu-Al powder and an appropriate amount of deionized water in a ball milling pot, and then put the ball milling pot in Ball milling in a planetary ball mill, take it out and grind to obtain dispersed precursor powder;

④Drying and purification: Put the above precursor powder in a drying oven for drying to remove the lubricating film formed by the process control agent on the surface of the ball milling particles to obtain dispersed CuO-Y ₂ O ₃ , Cu ₂ OY ₂ O ₃ or CuO - Al ₂ O ₃ , Cu ₂ O-Al ₂ O ₃ mixed precursor powder;

⑤ Calcination and reduction: Put the precursor powder obtained in step ④ into a high-temperature tube furnace for hydrogen reduction and calcination to obtain pure Cu-Y ₂ O ₃ or Cu-Al ₂ O ₃ copper-based composite powder, and then cool with the furnace;

⑥Vacuum hot pressing sintering: Put the Cu-Y ₂ O ₃ or Cu-Al ₂ O ₃ copper-based composite powder obtained in the above step ⑤ into the graphite mold, pre-press and put it into the vacuum hot pressing sintering equipment Evacuate, then raise the temperature and keep it for a certain period of time so that the particles can gain enough energy to migrate, and finally obtain a uniform phase, that is, Cu-Y ₂ O ₃ or Cu-Al ₂ O ₃ copper-based composite material.

As a preferred technical solution of the present invention, in the preparation method:

The purity of the copper ingot used in the step ① is 99.99%, and the purity of the yttrium ingot or aluminum ingot is 99.9%; in order to ensure that the ingot is completely melted, the total mass fraction of the yttrium ingot or aluminum ingot is set to be 1%, and the melting temperature The temperature is 1400℃, the temperature of the tundish is 1250℃, and the holding time is 8min.

In the step ②, the atomization pressure is set to 5Mpa, and in order to control the particle size of the powder, the diameter of the draft tube is controlled to be 3mm.

In the step ③, the ball milling speed is 400-600rpm, and the ball milling time is 48-72h; the vacuum glove box model used is ZKX, and the planetary ball mill is QM-QX4 omnidirectional planetary ball mill, with a ball-to-material ratio of 7:3; The assembly of the ball milling tank is completed in a vacuum glove box protected under an inert atmosphere to ensure a pure ball milling environment; both the spherical tank and the ball milling medium are made of hard alloy, which greatly reduces the probability of introducing impurities by mechanical alloying.

The amount of deionized water added in the step ③ is 15-25% of the powder mass.

In the step ④, the oven temperature is 110° C., and the drying time is 7 hours.

In the step ⑤, the tube furnace model GSL-1200X is heated to 550-650°C and kept for 1 hour, then cooled with the furnace, the heating rate is 10°C/min, and the cooling rate is 10°C/min.

The model of the sintering furnace for vacuum hot pressing sintering in the step ⑥ is HZK-270. After vacuuming, the temperature is raised to 1000°C and kept for 2 hours. The heating rate is 10°C/min, and the maximum pressure is 50MPa.

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

(1) The preparation process of the present invention combines smelting, rapid atomization, mechanical alloying and vacuum hot pressing sintering processes. Compared with a simple mechanical alloying process, the preparation process can maximize the uniform distribution of dispersed phase elements on copper In the matrix composite powder, it serves the purpose of pre-dispersion, shortens the time of mechanical alloying, and greatly reduces the introduction of impurities.

(2) The present invention first utilizes smelting and rapid atomization process to make dispersed phase element A uniformly distributed in the Cu matrix to form Cu-based powder containing A; secondly, mechanical alloying is used to promote the non-thermodynamic equilibrium diffusion of O, avoiding In the case of the precipitation of dispersed phase element A, the O element is evenly distributed throughout the Cu-based composite powder, and deionized water is used as an oxidant, which makes O evenly distributed in the Cu-based powder when mechanical alloying provides a large amount of energy . At the same time, deionized water can also act as a process control agent, forming a water film between powders, reducing powder agglomeration, and finally forming a fine dispersed phase. Compared with traditional carbon-containing process control agents, deionized water Much cleaner and more accessible. Uniformly distributed A and O elements react in situ to form oxide disperse particles, and finally sinter and form them by vacuum hot pressing to prepare dispersion-strengthened copper-based composites with fine disperse phase particles, high number density, uniform element distribution, and excellent comprehensive properties. .

Description of drawings

Fig. 1 is a schematic flow chart of preparing oxide dispersion strengthened copper matrix composite material according to the present invention.

Fig. 2 is the dispersed distribution phenomenon of Y in the copper matrix in the atomized powder prepared in Example 1.

Fig. 3 is a bulk transmission diagram of the oxide dispersion strengthened copper matrix composite material prepared in Example 1.

Fig. 4 is a graph showing the precipitation phenomenon of Y element in the oxide dispersion strengthened copper-based bulk composite material prepared in Comparative Example 1 at high temperature.

Fig. 5 is a diagram of bulk tensile properties of oxide dispersion strengthened copper matrix composites prepared in Example 1, Comparative Example 1 and Comparative Example 2.

Detailed ways

The preferred embodiments and comparative examples of the present invention will be described in detail below, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, so that the protection scope of the present invention can be defined more clearly.

Example 1

The Cu-Y ₂ O ₃ composite material in this example is made by high-temperature melting, gas atomization to prepare spheroidized alloy powder, mechanical alloying, calcining reduction, and vacuum hot-pressing sintering. Among them, the yttrium ingot accounts for The total mass ratio is 1%.

The preparation method of the Cu-Y ₂ O ₃ composite material in the present embodiment is as follows:

1. High-temperature smelting: Place copper ingots and yttrium ingots in the vacuum melting furnace of the gas atomization furnace, and pour the molten metal from the melting furnace into the tundish crucible under vacuum conditions. In order to ensure that the ingots are completely melted, among them The total mass fraction of yttrium ingot is set to be 1%, the melting temperature is 1400°C, the tundish temperature is 1250°C, and the holding time is 8 minutes.

2. Preparation of spheroidized alloy powder by gas atomization: After heat preservation, the casting liquid is introduced into the high-pressure gas atomizer, collected by the cyclone separator, and sieved to obtain the dispersed phase element Y through solid solution Cu-based composite atomized powder (Cu -Y); the atomization pressure is set to 5Mpa, in order to control the particle size of the powder, the diameter of the control draft tube is 3mm.

3. Mechanical alloying: the above-mentioned dispersed phase element Y supersolid solution Cu-based composite atomized powder (Cu-Y) powder and deionized water (20% of powder mass) are placed in a ball mill jar, and the ball mill speed (rotation speed) 500rpm, the ball milling time is 64h, the ball-to-material ratio is 7:3, and the assembly of the ball mill tank is completed in a vacuum glove box under the protection of an inert atmosphere, in which the ball tank and the ball mill medium are made of hard alloy, and the assembly is completed Finally, put the ball mill jar in a planetary ball mill for ball milling, take it out and grind to obtain dispersed precursor powder.

4. Drying and purification: put the above precursor powder in a drying oven, set the oven temperature to 110°C, and dry for 7 hours to remove the lubricating film formed by the process control agent on the surface of the ball-milled particles to obtain dispersed CuO-Y ₂ O ₃ or Cu ₂ OY ₂ O ₃ mixed precursor powder.

5. Calcination and reduction: put the precursor powder obtained in step 4 into a high-temperature tube furnace for hydrogen reduction and calcination to obtain pure Cu-Y ₂ O ₃ copper-based composite powder, and then cool with the furnace, wherein the reduction temperature is 600°C.

6. Vacuum hot pressing sintering: Put the Cu-Y ₂ O ₃ copper-based composite powder obtained in the above step 5 into a graphite mold, put it into a vacuum hot pressing sintering equipment after pre-pressing, pump to vacuum, and then heat up To 1000°C and keep it warm for 2 hours to make the particles gain enough energy to migrate. The maximum pressure is 50MPa, and finally a uniform phase is obtained. After the heat preservation is completed, the temperature is lowered to room temperature, and the Cu-Y ₂ O ₃ copper matrix composite material is obtained.

Example 2

The Cu-Al ₂ O ₃ composite material in this example is made by high-temperature melting, gas atomization to prepare spheroidized alloy powder, mechanical alloying, calcining reduction, and vacuum hot-pressing sintering. Among them, aluminum ingots account for The total mass ratio is 1%.

The preparation method of the Cu- _{Al2O3 composite} material in this embodiment is as follows:

1. High-temperature smelting: Place copper ingots and aluminum ingots in the vacuum melting furnace of the gas atomization furnace, and pour the molten metal from the melting furnace into the tundish crucible under vacuum conditions. In order to ensure that the ingots are completely melted, among them The total mass fraction of the aluminum ingot is set to be 1%, the melting temperature is 1400°C, the tundish temperature is 1250°C, and the holding time is 8 minutes.

2. Preparation of spheroidized alloy powder by gas atomization: After heat preservation, the casting liquid is introduced into the high-pressure gas atomizer, collected by the cyclone separator, and sieved to obtain the dispersed phase element Al persolid solution Cu-based composite atomized powder (Cu -Al); the atomization pressure is set to 5Mpa, in order to control the particle size of the powder, the diameter of the control draft tube is 3mm.

3. Mechanical alloying: the above-mentioned dispersed phase element Al supersolid solution Cu-based composite atomized powder (Cu-Al) powder and deionized water (20% of powder mass) are placed in a ball mill jar, and the ball mill speed (rotation speed) 500rpm, the ball milling time is 64h, the ball-to-material ratio is 7:3, and the assembly of the ball mill tank is completed in a vacuum glove box under the protection of an inert atmosphere, in which the ball tank and the ball mill medium are made of hard alloy, and the assembly is completed Finally, put the ball mill jar in a planetary ball mill for ball milling, take it out and grind to obtain dispersed precursor powder.

4. Drying and purification: put the above precursor powder in a drying oven, set the oven temperature to 110°C, and dry for 7 hours to remove the lubricating film formed by the process control agent on the surface of the ball mill particles to obtain dispersed CuO-Al ₂ O ₃ or Cu ₂ O-Al ₂ O ₃ mixed precursor powder.

5. Calcination and reduction: Put the precursor powder obtained in step 4 into a high-temperature tube furnace for hydrogen reduction and calcination to obtain pure Cu-Al ₂ O ₃ copper-based composite powder, and then cool with the furnace, wherein the reduction temperature is 600°C.

6. Vacuum hot-press sintering: put 15 g of the Cu-Al ₂ O ₃ copper-based composite powder obtained in the above step 5 into a graphite mold, put it into a vacuum hot-press sintering equipment after pre-pressing, and then evacuate to a vacuum, then Raise the temperature to 1000°C and keep it warm for 2 hours to make the particles gain enough energy to migrate. The maximum pressure is 50MPa, and finally a uniform phase is obtained. After the heat preservation is completed, the temperature is lowered to room temperature, and the Cu-Al ₂ O ₃ copper matrix composite material is obtained.

Comparative example 1

The Cu-Y ₂ O ₃ composite material in this example is made by high-temperature melting, gas atomization to prepare spheroidized alloy powder, internal oxidation, calcining reduction, and vacuum hot-pressing sintering. Among them, the yttrium ingot accounts for The total mass ratio is 1%.

The preparation method of the Cu-Y ₂ O ₃ composite material in the present embodiment is as follows:

1. High-temperature smelting: Place copper ingots and yttrium ingots in the vacuum melting furnace of the gas atomization furnace, and pour the molten metal from the melting furnace into the tundish crucible under vacuum conditions. In order to ensure that the ingots are completely melted, among them The total mass fraction of yttrium ingot is set to be 1%, the melting temperature is 1400°C, the tundish temperature is 1250°C, and the holding time is 8 minutes.

2. Preparation of spheroidized alloy powder by gas atomization: After heat preservation, the casting liquid is introduced into the high-pressure gas atomizer, collected by the cyclone separator, and sieved to obtain the dispersed phase element Y through solid solution Cu-based composite atomized powder (Cu -Y); the atomization pressure is set to 5Mpa, in order to control the particle size of the powder, the diameter of the control draft tube is 3mm.

3. Internal oxidation method: put the above-mentioned dispersed phase element Y oversolid solution Cu-based composite atomized powder (Cu-Y) powder and an appropriate amount of oxidant Cu ₂ O in a muffle furnace at a rate of 10 ° C per second The temperature was raised to 650°C, the internal oxidation time was 12h, and the dispersed precursor powder was obtained by grinding after taking it out.

4. Calcination and reduction: Put the precursor powder obtained in step 3 into a high-temperature tube furnace for hydrogen reduction and calcination to obtain pure Cu-Y ₂ O ₃ copper-based composite powder, and then cool with the furnace. The reduction temperature is 600°C.

5. Vacuum hot-press sintering: put the Cu-Y ₂ O ₃ copper-based composite powder obtained in the above steps into a graphite mold, put it into a vacuum hot-press sintering equipment after pre-pressing, then pump to vacuum, and then heat up to 1000°C and heat preservation for 2 hours to make the particles gain enough energy to migrate. The maximum pressure is 50MPa, and finally a uniform phase is obtained. After the heat preservation is completed, the temperature is cooled to room temperature, and the Cu-Y ₂ O ₃ copper matrix composite material is obtained.

Comparative example 2

The Cu-Y ₂ O ₃ composite material in this embodiment is a composite material made by a process of mechanical alloying, drying and purification, calcination reduction, and vacuum hot-pressing sintering, in which yttrium powder accounts for the total initial powder. 1% of mass.

The preparation method of the Cu-Y ₂ O ₃ composite material in the present embodiment is as follows:

1. Mechanical alloying: Copper powder and yttrium powder are placed in the ball mill jar, the mass ratio fraction of yttrium powder is 1%, and deionized water (20% of the total powder mass) is added therein, the ball milling speed is 500rpm, and the ball milling time For 64 hours, the assembly of the ball milling tank was completed in a vacuum glove box protected under an inert atmosphere, wherein the spherical tank and the ball milling medium were made of hard alloy. After the assembly was completed, the ball milling tank was installed and fixed in a planetary ball mill Afterwards, ball milling was carried out to obtain 30 g of dispersed precursor powder.

2. Drying and purification: put the above precursor powder in a drying oven, set the oven temperature to 110°C, and dry for 7 hours to remove the lubricating film formed by the process control agent on the surface of the ball mill particles to obtain dispersed CuO-Y ₂ O ₃ or Cu ₂ OY ₂ O ₃ mixed precursor powder.

3. Calcination reduction: Put the dispersed CuO-Y ₂ O ₃ or Cu ₂ OY ₂ O ₃ mixed precursor powder obtained in the above steps into a high-temperature tube furnace for calcination and reduction to obtain pure Cu-Y ₂ O ₃ copper The temperature is raised from room temperature to 600°C at a rate of 10°C per minute and kept for 1 hour and then cooled with the furnace. The atmosphere in the high-temperature tube furnace is the reducing gas hydrogen, and finally Cu-Y ₂ O ₃ is obtained. Copper-based composite powder.

4. Vacuum hot-press sintering: put the Cu-Y ₂ O ₃ copper-based composite powder obtained in the above steps into a graphite mold, put it into a vacuum hot-press sintering equipment after pre-pressing, pump it to vacuum, and then heat up to 1000°C and heat preservation for 2 hours to make the particles gain enough energy to migrate. The maximum pressure is 50MPa, and finally a uniform phase is obtained. After the heat preservation is completed, the temperature is cooled to room temperature, and the Cu-Y ₂ O ₃ copper matrix composite material is obtained.

The electrical conductivity, tensile strength and elongation performance tests were performed on the copper-based composite materials prepared in Examples 1 and 2, and Comparative Examples 1 and 2, and the results are shown in Table 1.

Copper-based composite electrical conductivity, tensile strength and elongation in the embodiment and comparative example of table 1

It can be seen from Figure 1 that this process is a composite material preparation method combining smelting atomization and mechanical alloying. First, the dispersed phase element Y or Al persolid solution Cu-based composite atomization is prepared by vacuum high-temperature melting and atomization treatment. Powder Cu-Y or Cu-Al, and then prepare the precursor powder by mechanical alloying process with deionized water as a process control agent and oxidant under the protection of an inert atmosphere, and then dry to remove the deionized water in the precursor The lubricating film formed on the surface of the body powder, and finally through calcination reduction and vacuum hot pressing sintering to obtain copper-based composite materials Cu-Y ₂ O ₃ or Cu-Al ₂ O ₃ .

It can be seen from Figure 2 that in the Cu-Y alloy powder obtained by atomization, the Y element is uniformly distributed in the copper matrix, which lays a solid foundation for the subsequent mechanical alloying to form a uniformly dispersed strengthening phase Y ₂ O ₃ .

It can be seen from Figure 3 that the size of the strengthening phase in Example 1 obtained by this process is small and the distribution is uniform, and the Y element is evenly distributed in the copper matrix after atomization, which reduces the in-situ formation of the dispersion strengthening phase during mechanical alloying. energy, so that it can play the role of fine-grain strengthening and dispersion strengthening comprehensively; while direct mechanical alloying refines the copper grains, but the distribution of the reinforcement phase formed is less uniform, so more fine-grain strengthening plays the role of strengthening effect, the strength of the material is slightly higher but the plasticity is obviously reduced. On the whole, compared with direct mechanical alloying, mechanical alloying after atomization significantly improves the plasticity and electrical conductivity of the material on the premise that the strength is slightly lower, making it superior in comprehensive performance.

It can be seen from Figure 4 that since the Y element is hardly dissolved in the copper matrix at high temperature, the high-temperature internal oxidation after atomization will cause the final Y ₂ O ₃ particle size to be coarse, which is its mechanical property. The main reason for the poor.

It can be seen from Figure 5 that compared with the traditional method of directly using mechanical alloying, this process significantly improves the plasticity of the composite material on the premise that the strength hardly decreases; compared with the traditional method of internal oxidation after atomization, this process The tensile strength and plasticity of the dispersion strengthened copper prepared by the process are obviously improved.

It can be seen from Table 1 that compared with the dispersion-strengthened copper-based materials prepared by the traditional method of atomization and internal oxidation and direct mechanical alloying, the composite material obtained by mechanical alloying after smelting atomization has higher conductivity The mechanical properties are significantly improved when the rate of decline is not obvious, making its comprehensive performance superior.

Table 2 Thermodynamic calculation results

It can be seen from Table 2 that the oxidation reaction has been verified by thermodynamic calculations. During the preparation process, deionized water and the dispersed phase precursor Y element undergo an oxidation reaction to form Y ₂ O ₃ . The reaction equation is as follows:

2Y+3H ₂ O——Y ₂ O ₃ +3H ₂

The thermodynamic analysis of the reaction system of Y and H ₂ O was carried out, and the Gibbs free energy of the reaction can be expressed as:

和

分别代表H₂、Y₂O₃、Y和H₂O的摩尔原子比。

和

分别代表H₂、Y₂O₃、Y和H₂O的吉布斯自由能；ΔG表示上述反应所需的吉布斯自由能。in,

and

represent the molar atomic ratios of H ₂ , Y ₂ O ₃ , Y and H ₂ O, respectively.

and

Respectively represent the Gibbs free energy of H ₂ , Y ₂ O ₃ , Y and H ₂ O; ΔG represents the Gibbs free energy required for the above reaction.

In summary, the present invention develops a process flow for preparing dispersion-strengthened copper-based composites by combining atomization and mechanical alloying, which can promote the non-thermodynamic equilibrium diffusion of O element while avoiding the polymerization of dispersed phase elements in Cu-based powders. , to ensure that the dispersed phase elements A and O are evenly distributed in the Cu-based powder, which greatly refines the dispersed phase and increases its number density, thereby obtaining a dispersion-strengthened copper-based material with excellent comprehensive properties; Oxidation process. In addition to preventing the segregation and aggregation of dispersed phase elements in the internal oxidation process, the inventive process is not limited by the solid solubility of the dispersed phase elements in the copper matrix. It broadens the types of dispersed phases and can prepare Dispersion-strengthened copper-based composites that cannot be prepared by conventional internal oxidation processes, such as Cu-Y ₂ O ₃ , Cu-ZrO ₂ , Cu-HfO ₂ ; compared to pure mechanical alloying processes, this invention can maximize the dispersion The phase elements are evenly distributed in the copper-based composite powder, which serves the purpose of pre-dispersion, shortens the mechanical alloying time, and greatly reduces the introduction of impurities.

At the same time, the present invention uses deionized water as an oxidizing agent and can be used as a process control agent. During the mechanical alloying process, a layer of deionized water film will be formed on the surface of Cu-based powder, which plays a role in inhibiting the formation of ductile Cu-based powder. The purpose of growth; the deionized water film on the surface of Cu-based powder is easier to remove after mechanical alloying, and will not remain on the particle surface, weakening the original particle boundary problem, and does not affect the adhesion between Cu-based particles in the subsequent sintering process. Knot.

The above content is only an example and description of the concept of the present invention. Those skilled in the art make various modifications or supplements to the described specific embodiments or replace them in similar ways, as long as they do not deviate from the concept of the invention Or beyond the scope defined in the claims, all should belong to the protection scope of the present invention.

Claims (9)

1. A method for preparing copper-based composite material by combining atomization and mechanical alloying is characterized in that firstly dispersed phase element Y or Al over-solid solution Cu-based composite atomized powder Cu-Y or Cu-Al is prepared by vacuum high temperature smelting and atomization treatment, then precursor powder is prepared by mechanical alloying process with deionized water as process control agent and oxidant under the protection of inert atmosphere, then lubrication film formed on the surface of the precursor powder by deionized water is removed by drying, and finally copper-based composite material Cu-Y is obtained by calcination reduction and vacuum hot-press sintering in sequence ₂ O ₃ Or Cu-Al ₂ O ₃ 。

2. The method of claim 1, characterized by the steps of:

(1) high-temperature smelting: placing copper ingots and yttrium ingots or copper ingots and aluminum ingots into a vacuum smelting furnace of an air atomizing furnace for smelting, and then pouring smelting molten metal into a tundish crucible from the smelting furnace under vacuum condition for heat preservation;

(2) preparing ball compound gold powder by gas atomization: the casting solution is guided into a high-pressure gas atomizer after heat preservation, collected by a cyclone separator and screened to obtain dispersed phase elements Y or Al oversoluble Cu-based composite atomized powder Cu-Y or Cu-Al with different particle sizes;

(3) mechanical alloying: placing the prepared dispersed phase element Y or Al over-solid solution Cu-based composite atomized powder Cu-Y or Cu-Al powder and a proper amount of deionized water into a ball milling tank, placing the ball milling tank into a planetary ball mill for ball milling, taking out and grinding to obtain dispersed precursor powder;

(4) and (3) drying and purifying: drying the precursor powder in a drying oven to remove a lubricating film formed on the surface of ball-milled particles by the process control agent, thereby obtaining dispersed CuO-Y ₂ O ₃ 、Cu ₂ O-Y ₂ O ₃ Or CuO-Al ₂ O ₃ 、Cu ₂ O-Al ₂ O ₃ Mixing the precursor powders;

(5) and (3) calcining and reducing: placing the precursor powder obtained in the step (4) into a high-temperature tube furnace for hydrogen reduction calcination to obtain pure Cu-Y ₂ O ₃ Or Cu-Al ₂ O ₃ Cooling the copper-based composite powder along with a furnace;

(6) vacuum hot pressing sintering: the Cu-Y obtained in the step (5) is treated ₂ O ₃ Or Cu-Al ₂ O ₃ Loading copper-based composite powder into a graphite mold, prepressing, placing into vacuum hot-pressing sintering equipment, vacuumizing, heating and maintaining for a certain time to obtain uniform phase, and obtaining Cu-Y ₂ O ₃ Or Cu-Al ₂ O ₃ Copper-based composite materials.

3. The method of claim 2, wherein the copper ingot used in step (1) has a purity of 99.99% and the yttrium or aluminum ingot has a purity of 99.9%; setting the total mass ratio of yttrium ingot or aluminum ingot to be 1%, smelting temperature to be 1400 ℃, tundish temperature to be 1250 ℃ and heat preservation time to be 8min.

4. The method according to claim 2, wherein the atomization pressure in the step (2) is set to 5Mpa, and the diameter of the draft tube is controlled to 3mm.

5. The method according to claim 2, wherein the ball milling rotation speed in the step (3) is 400-600rpm, and the ball milling time is 48-72 hours; the model of the vacuum glove box is ZKX, the planetary ball mill is QM-QX4 omnibearing planetary ball mill, and the ball-material ratio is 7:3; and (3) completing the assembly of the ball milling tank in a vacuum glove box under the protection of inert atmosphere, wherein the ball milling tank and the ball milling medium are both made of hard alloy.

6. The method of claim 2, wherein the deionized water is added in the amount of 15-25% of the powder mass in the step (3).

7. The method of claim 2, wherein the oven temperature in step (4) is 110 ℃ and the drying time is 7 hours.

8. The method of claim 2, wherein the tube furnace model GSL-1200X in step (5) is heated to 550-650 ℃ and incubated for 1h and then cooled with the furnace at a heating rate of 10 ℃/min and a cooling rate of 10 ℃/min.

9. The method of claim 2, wherein the sintering furnace model of the vacuum hot-pressed sintering in the step (6) is HZK-270, the temperature is raised to 1000 ℃ after vacuumizing and is kept for 2 hours, the temperature raising rate is 10 ℃/min, the highest pressure is 50MPa, and the furnace is cooled after the heat preservation is finished.

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