Preparation method of Cu-(Si3N4-Y2O3) composite material with excellent comprehensive performance

Abstract

The application relates to a preparation method of a Cu-(Si3N4-Y2O3) composite material with excellent comprehensive performance, and specifically comprises the following steps: (1) solid salt crystallization; (2) high-temperature nitriding calcination; (3) atomic level alloying; and (4) direct current pulse hot-pressing sintering. The application obtains uniformly dispersed composite powder through the solid salt crystallization and nitriding calcination method, and adds the composite powder into a copper matrix by using the atomic level alloying method, so that the dispersion strengthening effect is achieved; traditionally, a single hard phase Y2O3 is added, and the single hard phase Y2O3 has an undesirable strengthening effect when being added alone due to the coarsening of the single hard phase Y2O3 at high temperature. The Si3N4 material itself has the characteristics of high hardness, high strength, wear resistance and the like, and can inhibit the coarsening of yttrium oxide particles in the material preparation process, so that the dispersion strengthening effect is optimized, the mechanical properties of the material are greatly improved, the conductivity is maintained at a high level, and the excellent comprehensive performance of the copper-based material with high strength and high conductivity is realized.

Description

Technical Field

[0001] This invention belongs to the field of high-strength and high-conductivity copper-based composite material preparation technology, specifically involving a method for preparing Cu-(Si3N4-Y2O3) composite material with excellent comprehensive performance, which is a method for preparing high-strength and high-conductivity copper-based composite material for communication cables. Background Technology

[0002] Copper and its alloys are widely used in communication cables, resistance welding electrodes, and electrical contact materials due to their high conductivity and strength. However, with the development of technology, various materials, especially in the field of communication cables, have placed higher demands on the strength of copper and its alloys. Dispersion-strengthened copper (DS-Cu) is a metallic material strengthened by adding second-phase ceramic particles that are insoluble in the base metal to a copper matrix. It is usually prepared by powder metallurgy, so that the second phase is uniformly distributed in the base metal. DS-Cu can maintain its high level of conductivity and can maintain its dispersion strengthening effect at high temperatures, making it one of the mainstream copper alloys widely used in various industries. The traditionally added hard phase Y2O3 has an unsatisfactory strengthening effect when added alone due to its coarsening at high temperatures. Therefore, it is considered to add another non-metallic ceramic phase to cooperate with it to further improve the dispersion strengthening effect. Si3N4 material itself has the characteristics of high hardness, high strength, and wear resistance, and can inhibit the coarsening of yttrium oxide particles during the material preparation process, thus optimizing the dispersion strengthening effect. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing Cu-(Si3N4-Y2O3) composite materials with excellent comprehensive properties. The Cu-(Si3N4-Y2O3) copper-based composite materials prepared by this method can not only improve the mechanical properties of the material, but also improve the electrical conductivity of the material, thus meeting the application requirements.

[0004] To achieve the above objectives, the present invention employs the following technical solution:

[0005] A method for preparing Cu-(Si3N4-Y2O3) composite materials with excellent comprehensive properties includes the following steps:

[0006] (a) Solid salt crystallization

[0007] (1) Dissolve yttrium nitrate (Y(NO3)3·6H2O) powder in deionized water, stir thoroughly, and then add pure Si powder to the solution;

[0008] (2) Place the above mixture in a magnetic stirrer and heat and stir until the solution evaporates and the yttrium salt is completely precipitated and crystallized to obtain the precursor;

[0009] (3) The precursor obtained in step (2) is ground in a mortar to obtain a uniformly dispersed Si-Y(NO3)3 precursor powder;

[0010] (II) High-temperature nitridation calcination

[0011] The precursor powder prepared in step (I) is placed in a high-temperature tube furnace and subjected to nitridation and calcination under a nitrogen atmosphere to obtain a Si3N4-Y2O3 composite powder, the temperature is first increased at a rate of 10°C per minute from room temperature to 300°C, then held for 1 hour to ensure complete decomposition of yttrium nitrate, then increased at a rate of 10°C per minute to 1000°C, then increased at a rate of 5°C per minute to 1300°C-1400°C and held for 2-3 hours, then decreased at a rate of 5°C per minute to 1000°C, and finally decreased at a rate of 10°C per minute to 500°C, then cooled with the furnace, to obtain a Si3N4-Y2O3 powder;

[0012] (III) Atomic-level alloying

[0013] The Si3N4-Y2O3 powder prepared in step (II) and copper powder are placed in a ball mill jar, the mass fraction of Si3N4-Y2O3 powder is 2%-6%, the ball milling rotation speed (rotation speed) is 200-300 rpm, and the ball milling time is 12-18 hours, the assembly of the ball mill jar is completed in an argon atmosphere in a vacuum glove box to ensure that the ball milling process is carried out in an argon atmosphere to reduce the influence of oxygen in the air on the powder during atomic-level alloying, the ball jar and the ball milling medium are made of hard alloy, and after assembly, the ball mill jar is placed in a planetary ball mill, taken out and ground, to obtain a dispersed Cu-(Si3N4-Y2O3) composite powder;

[0014] (IV) Direct current pulse hot pressing sintering

[0015] (1) The Cu-(Si3N4-Y2O3) composite powder obtained in step (III) is loaded into a graphite mold, pre-pressed, and then the mold is placed in a direct current pulse hot pressing sintering furnace, the furnace chamber is vacuumed at room temperature, then heated to 600°C and held for 5 min;

[0016] (2) Then heated to 750°C-850°C and held for 5 min, then cooled to room temperature, to obtain a Cu-(Si3N4-Y2O3) composite material.

[0017] The purity of yttrium nitrate (Y(NO3)3·6H2O) and silicon powder in step (I) is 99%.

[0018] The tubular furnace model GSL-1200X is used in the step (ii), the heating rate is 5 °C / min~10 °C / min, and the cooling rate is 5 °C / min~10 °C / min.

[0019] The mass ratio of Si3N4 and Y2O3 in the step (ii) is 1:1.

[0020] The purity of the copper powder in the step (iii) is 99.5%, and the particle size is 25 μm, which is purchased from Chengdu Ketailong Alloy Co., Ltd.

[0021] The vacuum glove box model is ZKX, the planetary ball mill is QM-QX4 omnidirectional planetary ball mill, the ball-to-material ratio is 7:1, the ball milling speed (rotation speed) is 200~300 rpm, the ball milling time is 12~18 hours, the assembly of the ball milling tank is completed in the vacuum glove box to ensure a pure ball milling environment, and the ball milling medium and the small balls are both hard alloy, and the composition of the hard alloy is WC-Co.

[0022] The graphite mold diameter in the step (iv) is 20 mm.

[0023] The heating rate in the step (iv) is 100 °C / min, and the cooling rate is 100 °C / min.

[0024] The sintering furnace model for the direct current pulse hot pressing sintering in the step (iv) is LaboxTM-300, the pre-pressing pressure is 10 MPa, the sintering temperature is 750°C-850°C, the holding time is 5 min, and the final pressing pressure is 50 MPa.

[0025] The heating rate for the direct current pulse hot pressing sintering in the step (iv) is 100 °C / min, and the holding time at 600 °C is 5 min during the heating process, and the process from the pre-pressing to the final pressing is completed during the heating process from 600 °C to the sintering temperature.

[0026] The beneficial effects of the present application: unlike the contradiction between the mechanical properties and electrical conductivity of traditional copper alloys, the present application obtains uniformly dispersed composite powder by the method of solid salt crystallization and nitriding calcination, and adds the composite powder into the copper matrix by atomic level alloying method, so as to achieve the effect of dispersion strengthening; traditionally added single hard phase Y2O3 has an undesirable strengthening effect when added alone due to its coarsening at high temperature, and the addition of another non-metallic ceramic phase to cooperate with it can further improve the dispersion strengthening effect. Si3N4 material itself has high hardness, high strength, wear resistance and other characteristics, and can inhibit the coarsening of yttrium oxide particles during material preparation, so as to optimize the dispersion strengthening effect, greatly improve the mechanical properties of the material and maintain the electrical conductivity at a high level. In general, by using the composition design and preparation process of the present application, the excellent comprehensive performance of high strength and high conductivity of copper-based materials is realized. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is the SEM image of the composite material Cu-4 wt% (Si3N4-Y2O3);

[0028] Figure 2 is the EDS spectrum of the composite material Cu-4 wt% (Si3N4-Y2O3);

[0029] Figure 3 is the tensile fracture morphology diagram of the composite material Cu-4 wt% (Si3N4-Y2O3). DETAILED DESCRIPTION

[0030] The present application will be further described below in combination with specific examples.

[0031] Example 1

[0032] The Cu-(Si3N4-Y2O3) composite material in this embodiment is made by solid salt crystallization, nitriding calcination, atomic level alloying, and direct current pulse hot pressing sintering processing, wherein the mass fraction of Si3N4-Y2O3 is 2%.

[0033] The preparation method of the Cu-(Si3N4-Y2O3) composite material in this embodiment is as follows:

[0034] (1) Solid salt crystallization: first, dissolve yttrium nitrate (Y(NO3)3·6H2O) powder with a purity of 99% in deionized water, add pure Si powder to the solution after sufficient stirring, the addition amount of pure Si is 2.97 g, and the addition amount of yttrium nitrate (Y(NO3)3·6H2O) is 27.03 g, put the above mixture into a magnetic stirrer for heating and stirring, until the solution evaporates and the yttrium salt completely precipitates and crystallizes, then grind it in a mortar to obtain uniformly dispersed Si-Y(NO3)3 precursor powder;

[0035] (2) Nitriding and calcination: The above precursor powder was placed in a high-temperature tube furnace and nitrided and calcined under a nitrogen atmosphere to obtain Si3N4-Y2O3 composite powder. The temperature was first increased from room temperature to 300°C at a rate of 10°C per minute and then held for 1 hour to ensure complete decomposition of yttrium nitrate. Then the temperature was increased to 1000°C at a rate of 10°C per minute, then increased to 1300°C at a rate of 5°C per minute and held for 2 hours. Then the temperature was reduced to 1000°C at a rate of 5°C per minute and finally reduced to 500°C at a rate of 10°C per minute and cooled with the furnace to obtain Si3N4-Y2O3 powder.

[0036] (3) Atomic-level alloying: The Si3N4-Y2O3 powder and copper powder obtained in the previous step are placed in a ball mill jar. The mass fraction of Si3N4-Y2O3 powder is 2%. The ball milling speed (rotation speed) is 200 rpm, the ball milling time is 12 hours, and the ball-to-material ratio is 7:1. The ball mill jar is assembled in an argon atmosphere in a vacuum glove box to ensure that the ball milling process is carried out under the protection of an argon atmosphere to reduce the influence of oxygen in the air on the oxidation of powder during the atomic-level alloying process. The ball jar and the ball milling media are both made of hard alloy. After assembly, the ball mill jar is placed in a planetary ball mill for ball milling. After removal and grinding, dispersed Cu-2%wt (Si3N4-Y2O3) composite powder is finally obtained.

[0037] (4) DC pulse hot pressing sintering: Cu-2%wt (Si3N4-Y2O3) composite powder is loaded into a graphite mold, the powder surface is wrapped with carbon paper, and the mold is placed in a LaboxTM-300 DC pulse hot pressing sintering furnace. The furnace cavity is evacuated at room temperature, and then the temperature is raised to 600℃ and held for 5 min. The pre-pressure is set to 10 MPa. The temperature is then raised to 750℃ and held for 5 min. During the heating process, the pressure is manually increased to the final pressure of 50 MPa. The heating rate is 100 ℃ / min. After the holding period, the temperature is lowered to room temperature at a cooling rate of 100 ℃ / min to obtain Cu-2%wt (Si3N4-Y2O3) composite material.

[0038] Example 2

[0039] The Cu-(Si3N4-Y2O3) composite material in this embodiment is made by a solid salt crystallization, nitriding calcination, atomic-level alloying, and DC pulse hot pressing sintering process, wherein the mass fraction of Si3N4-Y2O3 is 4%.

[0040] The preparation method of the Cu-(Si3N4-Y2O3) composite material in this embodiment is as follows:

[0041] (1) Solid salt crystallization: First, yttrium nitrate (Y(NO3)3·6H2O) powder with a purity of 99% was dissolved in deionized water. After stirring thoroughly, pure Si powder was added to the solution. The amount of pure Si added was 2.97 g, and the amount of yttrium nitrate (Y(NO3)3·6H2O) added was 27.03 g. The mixture was placed in a magnetic stirrer and heated and stirred until the solution evaporated and the yttrium salt was completely precipitated and crystallized. Then, it was thoroughly ground in a mortar to finally obtain uniformly dispersed Si-Y(NO3)3 precursor powder.

[0042] (2) Nitriding and calcination: The above precursor powder was placed in a high-temperature tube furnace and nitrided and calcined under a nitrogen atmosphere to obtain Si3N4-Y2O3 composite powder. The temperature was first raised from room temperature to 300°C at a rate of 10°C per minute and then held for 1 hour to ensure complete decomposition of yttrium nitrate. Then the temperature was raised to 1000°C at a rate of 10°C per minute, then raised to 1350°C at a rate of 5°C per minute and held for 2.5 hours. Then the temperature was lowered to 1000°C at a rate of 5°C per minute and finally lowered to 500°C at a rate of 10°C per minute and cooled with the furnace to finally obtain Si3N4-Y2O3 powder.

[0043] (3) Atomic-level alloying: The Si3N4-Y2O3 powder and copper powder obtained in the previous step are placed in a ball mill jar. The mass fraction of Si3N4-Y2O3 powder is 4%. The ball milling speed (rotation speed) is 250 rpm. The ball milling time is 15 hours. The ball-to-material ratio is 7:1. The ball mill jar is assembled in an argon atmosphere in a vacuum glove box to ensure that the ball milling process is carried out under the protection of an argon atmosphere to reduce the influence of oxygen in the air on the oxidation of powder during the atomic-level alloying process. The ball jar and the ball milling media are both made of hard alloy. After assembly, the ball mill jar is placed in a planetary ball mill for ball milling. After removal and grinding, dispersed Cu-4%wt (Si3N4-Y2O3) composite powder is finally obtained.

[0044] (4) DC pulse hot pressing sintering: Cu-4%wt (Si3N4-Y2O3) composite powder is loaded into a graphite mold, the powder surface is wrapped with carbon paper, and the mold is placed in a LaboxTM-300 DC pulse hot pressing sintering furnace. The furnace cavity is evacuated at room temperature, and then the temperature is raised to 600℃ and held for 5 min. The pre-pressure is set to 10 MPa. The temperature is then raised to 800℃ and held for 5 min. During the heating process, the pressure is manually increased to the final pressure of 50 MPa. The heating rate is 100 ℃ / min. After the holding period, the temperature is lowered to room temperature at a cooling rate of 100 ℃ / min to obtain Cu-4%wt (Si3N4-Y2O3) composite material.

[0045] Example 3

[0046] The Cu-(Si3N4-Y2O3) composite material in this embodiment is made by a solid salt crystallization, nitriding calcination, atomic-level alloying, and DC pulse hot pressing sintering process, wherein the mass fraction of Si3N4-Y2O3 is 6%.

[0047] The preparation method of the Cu-(Si3N4-Y2O3) composite material in this embodiment is as follows:

[0048] (1) Solid salt crystallization: First, yttrium nitrate (Y(NO3)3·6H2O) powder with a purity of 99% was dissolved in deionized water. After stirring thoroughly, pure Si powder was added to the solution. The amount of pure Si added was 2.97 g, and the amount of yttrium nitrate (Y(NO3)3·6H2O) added was 27.03 g. The mixture was placed in a magnetic stirrer and heated and stirred until the solution evaporated and the yttrium salt was completely precipitated and crystallized. Then, it was thoroughly ground in a mortar to finally obtain uniformly dispersed Si-Y(NO3)3 precursor powder.

[0049] (2) Nitriding and calcination: The above precursor powder was placed in a high-temperature tube furnace and nitrided and calcined under a nitrogen atmosphere to obtain Si3N4-Y2O3 composite powder. The temperature was first increased from room temperature to 300°C at a rate of 10°C per minute and then held for 1 hour to ensure complete decomposition of yttrium nitrate. Then the temperature was increased to 1000°C at a rate of 10°C per minute, then increased to 1400°C at a rate of 5°C per minute and held for 3 hours. Then the temperature was reduced to 1000°C at a rate of 5°C per minute and finally reduced to 500°C at a rate of 10°C per minute and cooled with the furnace to obtain Si3N4-Y2O3 powder.

[0050] (3) Atomic-level alloying: The Si3N4-Y2O3 powder and copper powder obtained in the previous step were placed in a ball mill jar. The mass fraction of Si3N4-Y2O3 powder was 6%. The ball milling speed (rotation speed) was 300 rpm, the ball milling time was 18 hours, and the ball-to-material ratio was 7:1. The ball mill jar was assembled in an argon atmosphere in a vacuum glove box to ensure that the ball milling process was carried out under the protection of an argon atmosphere to reduce the influence of oxygen in the air oxidizing the powder during the atomic-level alloying process. The ball jar and the ball milling media were both made of hard alloy. After assembly, the ball mill jar was placed in a planetary ball mill for ball milling. After removal, it was ground to finally obtain dispersed Cu-6%wt (Si3N4-Y2O3) composite powder.

[0051] (4) DC pulse hot pressing sintering: Cu-6%wt.(Si3N4-Y2O3) composite powder is loaded into a graphite mold, the powder surface is wrapped with carbon paper, and the mold is placed in a LaboxTM-300 DC pulse hot pressing sintering furnace. The furnace cavity is evacuated at room temperature, and then the temperature is raised to 600℃ and held for 5 min. The pre-pressure is set to 10 MPa. The temperature is then raised to 850℃ and held for 5 min. During the heating process, the pressure is manually increased to the final pressure of 50 MPa. The heating rate is 100 ℃ / min. After the holding period, the temperature is lowered to room temperature at a cooling rate of 100 ℃ / min to obtain Cu-6%wt.(Si3N4-Y2O3) composite material.

[0052] The electrical conductivity and mechanical properties of the Cu-(Si3N4-Y2O3) composite materials in Examples 1-3 were tested, and the test results are shown in Table 1.

[0053] Table 1. Electrical and mechanical properties of Cu-(Si3N4-Y2O3) composite materials in Examples 1-3

[0054]

[0055] As can be seen from Table 1, compared with traditional single oxide dispersion reinforcing particles, adding another non-metallic ceramic phase to cooperate with the dispersion reinforcing particles significantly improves the overall performance of the composite material.

[0056] Depend on Figure 1 It can be seen that the second phase is mainly uniformly distributed at the grain boundaries, which can pin dislocations and grain boundary movements, thus helping to improve the mechanical properties of the composite material.

[0057] Depend on Figure 2 It can be seen that Y2O3 particles are mainly attached to Cu particles. The segregation of Si3N4 at the interface between the Cu matrix and Y2O3 particles can effectively reduce the interfacial energy and inhibit the coarsening of Y2O3 particles.

[0058] Depend on Figure 3 It can be seen that the fracture surface of the specimen after the tensile test exhibits dimples and quasi-cleavage morphology, and second-phase particles can be observed at the bottom of the dimples. Small particles are also distributed within the tear ridges, playing a role in transferring loads during the tensile process.

[0059] Unlike traditional copper alloys that suffer from a trade-off between mechanical properties and electrical conductivity, this invention achieves uniformly dispersed composite powder through solid salt crystallization and nitriding calcination. The composite powder is then added to the copper matrix using atomic-level alloying, resulting in dispersion strengthening. Traditionally, the addition of a single hard phase, Y₂O₃, results in unsatisfactory strengthening effects due to its coarsening at high temperatures. Adding another non-metallic ceramic phase further enhances the dispersion strengthening effect. Si₃N₄ material itself possesses high hardness, high strength, and wear resistance, and it can suppress the coarsening of yttrium oxide particles during material preparation, optimizing the dispersion strengthening effect. This significantly improves the material's mechanical properties while maintaining a high level of electrical conductivity. In summary, the compositional design and preparation process of this invention achieve excellent comprehensive performance of high strength and high conductivity in copper-based materials.

[0060] The above embodiments are merely illustrative of specific implementations of this disclosure, but the implementations of this disclosure are not limited to the above content. Any changes, modifications, substitutions, combinations, or simplifications made without substantially departing from the spirit and principle of the inventive concept of this disclosure shall be considered equivalent substitutions and included within the scope of protection defined by the claims.

Claims

1. A method for preparing Cu-(Si3N4-Y2O3) composite materials with excellent comprehensive properties, characterized in that: Specifically, the steps include the following: (a) Solid salt crystallization (1) Dissolve yttrium nitrate (Y(NO3)3·6H2O) powder in deionized water, stir thoroughly, and then add pure Si powder to the solution; (2) Place the above mixture in a magnetic stirrer and heat and stir until the solution evaporates and the yttrium salt is completely precipitated and crystallized to obtain the precursor; (3) Grind the precursor obtained in step (2) thoroughly in a mortar to finally obtain uniformly dispersed Si-Y(NO3)3 precursor powder; (ii) High-temperature nitriding calcination The precursor powder obtained in step (I) was placed in a high-temperature tube furnace and nitrided and calcined under a nitrogen atmosphere to obtain Si3N4-Y2O3 composite powder. The temperature was first increased from room temperature to 300°C at a rate of 10°C per minute and held for 1 hour to ensure complete decomposition of yttrium nitrate. Then, the temperature was increased to 1000°C at a rate of 10°C per minute, and then increased to 1300°C-1400°C at a rate of 5°C per minute and held for 2-3 hours. Then, the temperature was reduced to 1000°C at a rate of 5°C per minute and finally reduced to 500°C at a rate of 10°C per minute and cooled with the furnace to obtain Si3N4-Y2O3 powder. (III) Atomic-level alloying The Si3N4-Y2O3 powder and copper powder obtained in step (II) are placed in a ball mill jar. The mass fraction of Si3N4-Y2O3 powder is 2%-6%. The rotation speed of the ball mill is 200-300 rpm and the milling time is 12-18 hours. The ball mill jar is assembled in an argon atmosphere in a vacuum glove box to ensure that the milling process is carried out under the protection of an argon atmosphere to reduce the influence of oxygen in the air oxidizing the powder during the atomic-level alloying process. Both the ball mill jar and the milling media are made of hard alloy. After assembly, the ball mill jar is placed in a planetary ball mill for milling. After removal and grinding, dispersed Cu-(Si3N4-Y2O3) composite powder is finally obtained. (iv) DC pulse hot pressing sintering (1) The Cu-(Si3N4-Y2O3) composite powder obtained in step (3) is loaded into a graphite mold, pre-pressed, and then placed into a DC pulse hot pressing sintering furnace. The furnace cavity is evacuated at room temperature, and then heated to 600°C and held for 5 min. (2) Heat the temperature to 750°C-850°C and hold for 5 min. After holding, cool the temperature to room temperature to obtain Cu-(Si3N4-Y2O3) composite material.

2. The method for preparing a Cu-(Si3N4-Y2O3) composite material with excellent comprehensive properties as described in claim 1, characterized in that: In step (I), the purity of both yttrium nitrate (Y(NO3)3·6H2O) and silicon powder is 99%.

3. The method for preparing a Cu-(Si3N4-Y2O3) composite material with excellent comprehensive properties as described in claim 1, characterized in that: In step (II), the tubular furnace model is GSL-1200X.

4. The method for preparing a Cu-(Si3N4-Y2O3) composite material with excellent comprehensive properties as described in claim 1, characterized in that: In step (ii), the mass ratio of Si3N4 to Y2O3 is 1:

1.

5. The method for preparing a Cu-(Si3N4-Y2O3) composite material with excellent comprehensive properties as described in claim 1, characterized in that: In step (iii), the copper powder has a purity of 99.5% and a particle size of 25 μm.

6. The method for preparing a Cu-(Si3N4-Y2O3) composite material with excellent comprehensive properties as described in claim 1, characterized in that: In step (iii), the vacuum glove box is model ZKX, the planetary ball mill is QM-QX4 omnidirectional planetary ball mill, the ball-to-material ratio is 7:1, the ball mill's rotation speed is 200-300 rpm, and the ball milling time is 12-18 hours. The assembly of the ball mill jar is completed in the vacuum glove box to ensure a pure ball milling environment. The ball milling media and small balls are all cemented carbide, and the composition of this cemented carbide is WC-Co.

7. The method for preparing a Cu-(Si3N4-Y2O3) composite material with excellent comprehensive properties as described in claim 1, characterized in that: In step (iv), the diameter of the graphite mold is 20 mm.

8. The method for preparing a Cu-(Si3N4-Y2O3) composite material with excellent comprehensive properties as described in claim 1, characterized in that: In step (iv), the heating rate is 100 °C / min and the cooling rate is 100 °C / min.

9. The method for preparing a Cu-(Si3N4-Y2O3) composite material with excellent comprehensive properties as described in claim 1, characterized in that: In step (iv), the sintering furnace used for DC pulse hot pressing is a LaboxTM-300, with a pre-pressing pressure of 10 MPa, a sintering temperature of 750°C-850°C, a holding time of 5 min, and a final pressure of 50 MPa.

10. The method for preparing a Cu-(Si3N4-Y2O3) composite material with excellent comprehensive properties as described in claim 1, characterized in that: In step (iv), the heating rate of DC pulse hot pressing sintering is 100°C / min. During the heating process, the temperature is held at 600°C for 5 minutes. The process of pre-pressing to final pressing is completed during the heating process from 600°C to the sintering temperature.

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