Preparation method of tungsten-infiltrated aluminum dissipative heat-resistant composite material

Abstract

A method for preparing a tungsten-infiltrated aluminum dissipative heat-proof composite material relates to a method for preparing a dissipative heat-proof composite material. In order to solve the problems of poor ablation resistance and poor oxidation resistance of rocket engine throat lining materials, a method for preparing a tungsten-infiltrated aluminum dissipative heat-proof composite material is proposed. The tungsten of the present invention is used as a sintering aid. Due to the high-temperature stability and good thermal conductivity of tungsten, the heating process is more uniform. The densification effect is improved by accelerating the atomic diffusion inside the material, which helps to improve the density of the composite material. The presence of tungsten during the sintering process can promote the densification of aluminum powder and reduce porosity; tungsten has high thermal conductivity and can significantly improve the thermal conductivity of the composite material. Good thermal conductivity is conducive to the uniform distribution of heat, avoiding the problems of local overheating or uneven cooling, and thus ensuring the internal quality and consistency of the composite material. The density of aluminum alloy is low, and the porous tungsten skeleton can provide sufficient strength to meet the requirements of light weight and high strength.

Description

Technical Field

[0001] The invention relates to a preparation method of a dissipative heat-proof composite material. Background Art

[0002] With the development of aerospace, the requirements for propulsion technology are becoming increasingly stringent. Rocket engine throat liners must withstand extreme service conditions such as high pressure, ultra-high temperature, and high-velocity airflow erosion. Rocket engine throat liners are a key component in ensuring stable engine thrust. Therefore, research on throat liner materials is crucial to improving rocket engine performance.

[0003] Currently, common metal composite materials for throat linings include tungsten-copper and tungsten-molybdenum-copper. Tungsten-copper combines the high melting point, high hardness, and excellent heat resistance of tungsten with the good thermal and electrical conductivity of copper. However, under extremely high temperatures, the copper component easily oxidizes, reducing the material's durability, thermal conductivity, and mechanical properties. Tungsten-copper is currently produced using powder metallurgy, which involves mixing, pressing, and sintering. These steps are cumbersome and require demanding process conditions, making large-scale production difficult. Furthermore, the high hardness of tungsten and the relative softness of copper complicate processing and extend production cycles. While the addition of molybdenum to tungsten-molybdenum-copper improves the material's mechanical properties somewhat, copper's high oxidation resistance at high temperatures prevents the formation of a dense oxide layer to isolate oxygen, leading to internal oxidation. This still limits the material's high-temperature ablation and fabrication capabilities. In addition, both tungsten-copper materials and tungsten-molybdenum-copper materials have the problems of high density and easy oxidation and ablation at high temperatures, and cannot meet the requirements of light weight, high strength and resistance to oxidation and ablation. Summary of the Invention

[0004] In order to solve the problem of poor ablation resistance and oxidation resistance of rocket engine throat lining materials, the present invention proposes a preparation method of tungsten-infiltrated aluminum dissipative heat-resistant composite material.

[0005] In the tungsten-infiltrated aluminum dissipative heat-protective composite material of the present invention, tungsten serves as a sintering aid. Due to its high-temperature stability and good thermal conductivity, tungsten makes the heating process more uniform, thereby accelerating the atomic diffusion inside the material and improving the densification effect. Therefore, the addition of tungsten helps to improve the density of the composite material. The presence of tungsten during the sintering process can promote the densification of aluminum powder and reduce porosity. Tungsten has high thermal conductivity and can significantly improve the thermal conductivity of the composite material. Good thermal conductivity is conducive to the uniform distribution of heat, avoiding the problems of local overheating or uneven cooling, and thus ensuring the internal quality and consistency of the composite material.

[0006] The preparation method of the tungsten-infiltrated aluminized dissipative heat-resistant composite material of the present invention is carried out by the following steps:

[0007] 1. Weigh W powder and aluminum alloy powder:

[0008] Weigh 200g-300g of W powder and 43g-55g of aluminum alloy powder;

[0009] 2. Sintering of porous tungsten skeleton:

[0010] The tungsten powder weighed in step 1 and 3g to 5g of aluminum alloy powder are mixed and placed in a ball mill to obtain an alloy mixed powder; the alloy mixed powder is placed in a graphite mold, and the mold is placed in a spark plasma sintering furnace cavity, and a pressure of 10MPa to 60MPa is applied under vacuum conditions for compaction, and then the temperature is increased to 800°C to 1000°C at a heating rate of 80°C / min to 100°C / min, and then increased to 1200°C to 1500°C at a heating rate of 40°C / min to 50°C / min, and finally spark plasma sintering is performed. After sintering, the mixture is cooled to room temperature with the furnace, and then demolded to obtain a porous tungsten skeleton;

[0011] Step 2: The spark plasma sintering process is as follows: the vacuum degree is 10 -3 Pa, sintering time is 3min~7min, applied pressure is 10MPa~60MPa, sintering current is DC pulse current of 1000A-3000A, sintering power is 5kW~10kW;

[0012] The ball milling process in step 2 is as follows: using a planetary ball mill, a ball-to-material ratio of 1:(5-25), a ball milling temperature of 30°C to 70°C, a ball milling speed of 100 rpm to 500 rpm, and a ball milling time of 4h to 20h;

[0013] 3. Preparation of tungsten-infiltrated aluminum-dissipated heat-resistant composite materials by pressure infiltration

[0014] The porous tungsten skeleton obtained in step 2 is loaded into a pressure infiltration mold, and then the mold is placed in a heating furnace, the temperature of the heating furnace is raised from room temperature to 450°C to 650°C and kept warm for 5min to 10min to obtain a preheated tungsten skeleton; the remaining aluminum alloy powder weighed in step 1 is heated to melt to obtain molten aluminum alloy liquid; the molten aluminum alloy liquid is poured onto the preheated tungsten skeleton in the mold, and a pressure of 90kN to 150kN is applied by a press to infiltrate the molten aluminum alloy liquid into the pores of the preheated tungsten skeleton; after the molten aluminum alloy liquid is completely infiltrated into the preheated tungsten skeleton preform, it is placed in air for cooling, and after cooling, the ingot is demolded to obtain the tungsten infiltrated aluminum heat-resistant composite material.

[0015] The present invention has the following beneficial effects:

[0016] 1. The present invention utilizes aluminum alloy as the dissipative agent in a tungsten-based dissipative heat-protective composite material. The aluminum alloy's low melting point and high volatility can quickly dissipate large amounts of heat, reducing the material temperature and addressing the ablation resistance of conventional rocket engine throat lining materials. Furthermore, the aluminum alloy vapor generated after melting and vaporization acts as a reducing agent, forming a dense, high-temperature-resistant aluminum oxide layer that provides excellent thermal insulation and anti-oxidation properties. The aluminum alloy's low density, combined with the porous tungsten skeleton, provides sufficient strength, meeting the requirements of lightweight and high strength.

[0017] 2. The present invention provides a method for preparing a tungsten-infiltrated aluminum dissipative heat-protective composite material by using discharge plasma sintering and pressure infiltration. First, a pulse current is used to generate plasma, and the plasma is used as a heat source. The ultra-high temperature characteristics of the plasma are used to rapidly heat the embryo body, and the tungsten skeleton is sintered under axial pressure. Then, the pressure infiltration technology is used to infiltrate the molten aluminum alloy liquid into the pores of the tungsten skeleton. Finally, a dissipative heat-protective composite material with resistance to ablation and oxidation is obtained. The aluminum alloy powder used in the present invention has a low melting point. Compared with the tungsten-copper material prepared by powder metallurgy, the present invention has low requirements for preparation equipment and low energy consumption, which is conducive to reducing costs and improving production efficiency. In addition, the process method is simple and easy to operate, does not require the use of chemical reagents harmful to the environment, is energy-saving and environmentally friendly, has low cost, and is easy to realize industrial production and application.

[0018] 3. When preparing tungsten skeletons, the present invention can control the particle size of tungsten powder and axial pressure, so that tungsten skeletons with different porosities and pore sizes can be prepared, and has the ability to prepare different materials according to different usage requirements.

[0019] 4. The present invention mixes tungsten powder with a small amount of aluminum alloy powder and ball-mills them before SPS sintering. W powder and Al powder are ball-milled and then sintered. W powder and W powder are linked by AlW compound. The reaction temperature of W and Al is lower, so the sintering temperature can be reduced, thereby reducing energy consumption, which is beneficial to reducing costs and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a macroscopic photograph of the tungsten-infiltrated aluminum dissipative heat-protective composite material prepared in Example 1 after ablation. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is not limited to the specific implementation methods listed below, but also includes any reasonable combination of the specific implementation methods.

[0022] Specific embodiment 1: The preparation method of the tungsten-infiltrated aluminum dissipative heat-resistant composite material in this embodiment is carried out according to the following steps:

[0023] 1. Weigh W powder and aluminum alloy powder:

[0024] Weigh 200g-300g of W powder and 43g-55g of aluminum alloy powder;

[0025] 2. Sintering of porous tungsten skeleton:

[0026] The tungsten powder weighed in step 1 and 3g to 5g of aluminum alloy powder are mixed and placed in a ball mill to obtain an alloy mixed powder; the alloy mixed powder is placed in a graphite mold, and then the mold is placed in a spark plasma sintering furnace cavity, and a pressure of 10MPa to 60MPa is applied under vacuum conditions for compaction, and then the temperature is increased to 800°C to 1000°C at a heating rate of 80°C / min to 100°C / min, and then increased to 1200°C to 1500°C at a heating rate of 40°C / min to 50°C / min, and finally spark plasma sintering is performed. After sintering, the mixture is cooled to room temperature with the furnace, and then demolded to obtain a porous tungsten skeleton;

[0027] Step 2: The spark plasma sintering process is as follows: the vacuum degree is 10 -3 Pa, sintering time is 3min~7min, applied pressure is 10MPa~60MPa, sintering current is DC pulse current of 1000A-3000A, sintering power is 5kW~10kW;

[0028] The ball milling process in step 2 is as follows: using a planetary ball mill, a ball-to-material ratio of 1:(5-25), a ball milling temperature of 30°C to 70°C, a ball milling speed of 100 rpm to 500 rpm, and a ball milling time of 4h to 20h;

[0029] 3. Preparation of tungsten-infiltrated aluminum-dissipated heat-resistant composite materials by pressure infiltration

[0030] The porous tungsten skeleton obtained in step 2 is loaded into a pressure infiltration mold, and then the mold is placed in a heating furnace, the temperature of the heating furnace is raised from room temperature to 450°C to 650°C and kept warm for 5min to 10min to obtain a preheated tungsten skeleton; the remaining aluminum alloy powder weighed in step 1 is heated to melt to obtain molten aluminum alloy liquid; the molten aluminum alloy liquid is poured onto the preheated tungsten skeleton in the mold, and a pressure of 90kN to 150kN is applied by a press to infiltrate the molten aluminum alloy liquid into the pores of the preheated tungsten skeleton; after the molten aluminum alloy liquid is completely infiltrated into the preheated tungsten skeleton preform, it is placed in air for cooling, and after cooling, the ingot is demolded to obtain the tungsten infiltrated aluminum heat-resistant composite material.

[0031] This embodiment has the following beneficial effects:

[0032] 1. This embodiment utilizes aluminum alloy as the dissipative agent in a tungsten-based dissipative heat-protective composite material. The low melting point and high volatility of aluminum alloy can quickly dissipate large amounts of heat, reducing the material temperature and addressing the ablation resistance of traditional rocket engine throat lining materials. Furthermore, the aluminum alloy vapor generated after melting and vaporization acts as a reducing agent, forming a dense, high-temperature resistant aluminum oxide layer that provides excellent thermal insulation and anti-oxidation properties. The aluminum alloy has a low density, and the porous tungsten skeleton provides sufficient strength to meet the requirements of lightweight and high strength.

[0033] 2. This embodiment provides a method for preparing a tungsten-infiltrated aluminum dissipative heat-protective composite material by using discharge plasma sintering and pressure infiltration. First, a pulse current is used to generate plasma, and the plasma is used as a heat source. The ultra-high temperature characteristics are used to rapidly heat the embryo body, and the tungsten skeleton is sintered under axial pressure. Then, the pressure infiltration technology is used to infiltrate the molten aluminum alloy liquid into the pores of the tungsten skeleton. Finally, a dissipative heat-protective composite material with resistance to ablation and oxidation is obtained. The aluminum alloy powder used in this embodiment has a low melting point. Compared with the tungsten-copper material prepared by powder metallurgy, this embodiment has low requirements for preparation equipment and low energy consumption, which is conducive to reducing costs and improving production efficiency. In addition, the process method is simple and easy to operate, does not require the use of chemical reagents harmful to the environment, is energy-saving and environmentally friendly, has low cost, and is easy to realize industrial production and application.

[0034] 3. In preparing the tungsten skeleton, the particle size of the tungsten powder and the axial pressure can be controlled in this embodiment, so that tungsten skeletons with different porosities and pore sizes can be prepared, and different materials can be prepared according to different usage requirements.

[0035] 4. In this embodiment, tungsten powder is mixed with a small amount of aluminum alloy powder and ball-milled before SPS sintering. W powder and Al powder are ball-milled and then sintered. W powder and W powder are linked by AlW compound. The reaction temperature of W and Al is lower, so the sintering temperature can be reduced, thereby reducing energy consumption, which is beneficial to reducing costs and improving production efficiency.

[0036] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that the particle size of the W powder in step 1 is 10 μm to 100 μm.

[0037] Specific embodiment three: This embodiment differs from specific embodiment one or two in that: the aluminum alloy powder in step one is pure aluminum alloy.

[0038] Specific embodiment four: This embodiment differs from specific embodiment three in that: the aluminum alloy is one or a combination of Al-Si alloy, Al-Si-Cu alloy, Al-Si-Mg alloy, Al-Si-Cu-Mg alloy; the mass fraction of Si in the Al-Si alloy is 0.5% to 25%; the mass fraction of Si in the Al-Si-Cu alloy is 0.5% to 25%, and the mass fraction of Cu is 0.5% to 53%; the mass fraction of Si in the Al-Si-Mg alloy is 0.5% to 25%, and the mass fraction of Mg is 0.5% to 38%; the mass fraction of Zn in the Al-Zn-Cu alloy is 0.5% to 55%, and the mass fraction of Cu is 0.5% to 53%; the mass fraction of Si in the Al-Si-Cu-Mg alloy is 0.5% to 25%, the mass fraction of Cu is 0.5% to 53%, and the mass fraction of Mg is 0.5% to 38%.

[0039] Specific embodiment 5: This embodiment differs from any one of specific embodiments 1 to 4 in that: Step 1: weigh 250 g of W powder and 55 g of aluminum alloy powder.

[0040] Specific embodiment six: This embodiment differs from any of specific embodiments one to five in that: in step two, the mold is placed in the cavity of a spark plasma sintering furnace, and a pressure of 30 MPa is applied under vacuum conditions for compaction. The temperature is then raised to 1000°C at a heating rate of 100°C / min, and then raised to 1500°C at a heating rate of 50°C / min. Finally, spark plasma sintering is performed. After sintering is completed, the mold is cooled to room temperature with the furnace, and then demolded to obtain a porous tungsten skeleton.

[0041] Specific embodiment seven: This embodiment differs from any one of the specific embodiments one to six in that: the spark plasma sintering process in step two is: the vacuum degree is 10 -3 Pa, the sintering time is 5 min, the applied pressure is 30 MPa, the sintering current is a DC pulse current of 2600 A, and the sintering power is 10 kW.

[0042] Specific embodiment eight: This embodiment differs from any one of specific embodiments one to seven in that: the ball milling process in step two is: using a planetary ball mill, a ball-to-material ratio of 1:10, a ball milling temperature of 40°C, a ball milling speed of 300 rpm, and a ball milling time of 10 h.

[0043] Specific embodiment 9: This embodiment differs from any one of specific embodiments 1 to 8 in that: in step 3, the mold is placed in a heating furnace, and the temperature of the heating furnace is raised from room temperature to 500° C. and kept warm for 5 minutes.

[0044] Specific embodiment ten: This embodiment differs from any one of specific embodiments one to nine in that: in step four, a pressure of 100 kN is applied by a press to allow the molten aluminum alloy to infiltrate the pores of the preheated tungsten skeleton.

[0045] Example 1:

[0046] The preparation method of the tungsten-infiltrated aluminized dissipative heat-resistant composite material of this embodiment is carried out by the following steps:

[0047] 1. Weigh W powder and aluminum alloy powder:

[0048] Weigh 250g of W powder and 55g of aluminum alloy powder;

[0049] The particle size of the W powder in step 1 is 50 μm;

[0050] The aluminum alloy powder in step 1 is pure aluminum alloy; the aluminum alloy is Al-Si alloy; the mass fraction of Si in the Al-Si alloy is 1%;

[0051] 2. Sintering of porous tungsten skeleton:

[0052] The tungsten powder weighed in step 1 and 5 g of aluminum alloy powder were mixed and placed in a ball mill to obtain an alloy mixed powder; the alloy mixed powder was placed in a graphite mold, and the mold was placed in a spark plasma sintering furnace cavity. A pressure of 30 MPa was applied under vacuum conditions for compaction, and then the temperature was increased to 1000°C at a rate of 100°C / min, and then increased to 1500°C at a rate of 50°C / min. Finally, spark plasma sintering was performed. After sintering, the mixture was cooled to room temperature in the furnace and then demolded to obtain a porous tungsten skeleton.

[0053] Step 2: The spark plasma sintering process is as follows: the vacuum degree is 10 -3 Pa, sintering time was 5 min, applied pressure was 30 MPa, sintering current was 2600 A DC pulse current, and sintering power was 10 kW;

[0054] The ball milling process in step 2 is as follows: using a planetary ball mill, a ball-to-material ratio of 1:10, a ball milling temperature of 40° C., a ball milling speed of 300 rpm, and a ball milling time of 10 h;

[0055] 3. Preparation of tungsten-infiltrated aluminum-dissipated heat-resistant composite materials by pressure infiltration

[0056] The porous tungsten skeleton obtained in step 2 is loaded into a pressure infiltration mold, and then the mold is placed in a heating furnace, the temperature of the heating furnace is raised from room temperature to 500°C and kept warm for 5 minutes to obtain a preheated tungsten skeleton; the remaining aluminum alloy powder weighed in step 1 is heated to melt to obtain molten aluminum alloy liquid; the molten aluminum alloy liquid is poured onto the preheated tungsten skeleton in the mold, and a pressure of 100kN is applied by a press to allow the molten aluminum alloy liquid to infiltrate the pores of the preheated tungsten skeleton; after the molten aluminum alloy liquid is completely infiltrated into the preheated tungsten skeleton preform, it is placed in air for cooling, and after cooling, it is demolded to obtain an ingot, that is, a tungsten-infiltrated aluminum dissipative heat-resistant composite material.

[0057] Figure 1 This is a macroscopic photograph of the tungsten-infiltrated aluminum dissipative heat-protective composite material obtained in Example 1 after ablation by oxyacetylene gas. It can be seen that after ablation, an obvious ablation pit appeared in the center of the ablation sample. In the edge area of ​​the ablation sample, the number of silver-gray particles can be seen to decrease and be replaced by yellow powder. In the transition zone, a large amount of bright yellow powder can be seen attached to the surface of the ablation sample, still showing radial characteristics, indicating that the dissipative agent can melt and seep out of the matrix to form a melt liquid film during the ablation process, and the liquid film can reduce the scouring effect of the ablation sample by the high-speed oxyacetylene gas flow, indicating the feasibility of the dissipative heat-protective design.

[0058] The density of the tungsten-infiltrated aluminized heat-dissipating composite material prepared in this embodiment is 9.5429 g / cm -3 , the bending strength at 900K is 658MPa, and the ablation rate is 1.12μm / s.

[0059] Example 2:

[0060] The preparation method of the tungsten-infiltrated aluminized dissipative heat-resistant composite material of this embodiment is carried out by the following steps:

[0061] 1. Weigh W powder and aluminum alloy powder:

[0062] Weigh 250g of W powder and 55g of aluminum alloy powder;

[0063] The particle size of the W powder in step 1 is 70 μm;

[0064] The aluminum alloy powder in step 1 is pure aluminum alloy; the aluminum alloy is Al-Si alloy; the mass fraction of Si in the Al-Si alloy is 5%;

[0065] 2. Sintering of porous tungsten skeleton:

[0066] The tungsten powder weighed in step 1 and 5 g of aluminum alloy powder were mixed and placed in a ball mill to obtain an alloy mixed powder; the alloy mixed powder was placed in a graphite mold, and the mold was placed in a spark plasma sintering furnace cavity. A pressure of 40 MPa was applied under vacuum conditions for compaction, and then the temperature was increased to 900°C at a rate of 90°C / min, and then increased to 1400°C at a rate of 50°C / min. Finally, spark plasma sintering was performed. After sintering, the mixture was cooled to room temperature in the furnace and then demolded to obtain a porous tungsten skeleton.

[0067] Step 2: The spark plasma sintering process is as follows: the vacuum degree is 10 -3 Pa, sintering time was 5 min, applied pressure was 40 MPa, sintering current was 2600 A DC pulse current, and sintering power was 10 kW;

[0068] The ball milling process in step 2 is as follows: using a planetary ball mill, a ball-to-material ratio of 1:15, a ball milling temperature of 35° C., a ball milling speed of 370 rpm, and a ball milling time of 9 h;

[0069] 3. Preparation of tungsten-infiltrated aluminum-dissipated heat-resistant composite materials by pressure infiltration

[0070] The porous tungsten skeleton obtained in step 2 is loaded into a pressure infiltration mold, and then the mold is placed in a heating furnace, the temperature of the heating furnace is raised from room temperature to 600°C and kept warm for 6 minutes to obtain a preheated tungsten skeleton; the remaining aluminum alloy powder weighed in step 1 is heated to melt to obtain molten aluminum alloy liquid; the molten aluminum alloy liquid is poured onto the preheated tungsten skeleton in the mold, and a pressure of 120kN is applied by a press to infiltrate the molten aluminum alloy liquid into the pores of the preheated tungsten skeleton; after the molten aluminum alloy liquid is completely infiltrated into the preheated tungsten skeleton preform, it is placed in air for cooling, and after cooling, the ingot is demolded to obtain the tungsten infiltrated aluminum heat-resistant composite material.

[0071] The density of the tungsten-infiltrated aluminized heat-resistant composite material prepared in this embodiment is 9.6489 g / cm -3 , the bending strength at 900K is 806MPa, and the ablation rate is 1.31μm / s.

[0072] Example 3:

[0073] The preparation method of the tungsten-infiltrated aluminized dissipative heat-resistant composite material of this embodiment is carried out by the following steps:

[0074] 1. Weigh W powder and aluminum alloy powder:

[0075] Weigh 250g of W powder and 55g of aluminum alloy powder;

[0076] The particle size of the W powder in step 1 is 40 μm;

[0077] The aluminum alloy powder in step 1 is pure aluminum alloy; the aluminum alloy is Al-Si-Mg alloy, wherein the mass fraction of Si in the Al-Si-Mg alloy is 3% and the mass fraction of Mg is 10%;

[0078] 2. Sintering of porous tungsten skeleton:

[0079] The tungsten powder weighed in step 1 and 5 g of aluminum alloy powder were mixed and placed in a ball mill to obtain an alloy mixed powder; the alloy mixed powder was placed in a graphite mold, and the mold was placed in a spark plasma sintering furnace cavity. A pressure of 30 MPa was applied under vacuum conditions for compaction, and then the temperature was increased to 1000°C at a rate of 100°C / min, and then increased to 1500°C at a rate of 50°C / min. Finally, spark plasma sintering was performed. After sintering, the mixture was cooled to room temperature in the furnace and then demolded to obtain a porous tungsten skeleton.

[0080] Step 2: The spark plasma sintering process is as follows: the vacuum degree is 10 -3 Pa, sintering time was 5 min, applied pressure was 30 MPa, sintering current was 2600 A DC pulse current, and sintering power was 10 kW;

[0081] The ball milling process in step 2 is as follows: using a planetary ball mill, a ball-to-material ratio of 1:8, a ball milling temperature of 30° C., a ball milling speed of 230 rpm, and a ball milling time of 15 h;

[0082] 3. Preparation of tungsten-infiltrated aluminum-dissipated heat-resistant composite materials by pressure infiltration

[0083] The porous tungsten skeleton obtained in step 2 is loaded into a pressure infiltration mold, and then the mold is placed in a heating furnace, the temperature of the heating furnace is raised from room temperature to 650°C and kept warm for 10 minutes to obtain a preheated tungsten skeleton; the remaining aluminum alloy powder weighed in step 1 is heated to melt to obtain molten aluminum alloy liquid; the molten aluminum alloy liquid is poured onto the preheated tungsten skeleton in the mold, and a pressure of 100kN is applied by a press to infiltrate the molten aluminum alloy liquid into the pores of the preheated tungsten skeleton; after the molten aluminum alloy liquid is completely infiltrated into the preheated tungsten skeleton preform, it is placed in air for cooling, and after cooling, it is demolded to obtain an ingot, that is, a tungsten-infiltrated aluminum dissipative heat-resistant composite material.

[0084] The density of the tungsten-infiltrated aluminized heat-resistant composite material prepared in this embodiment is 9.5089 g / cm -3 The bending strength at 900K is 724MPa and the ablation rate is 1.29μm / s.

Claims

1. A method for preparing a tungsten-aluminized dissipative heat-resistant composite material, characterized by: The preparation method of tungsten-infiltrated aluminized dissipative heat-protective composite material is carried out in the following steps:

1. Weigh W powder and aluminum alloy powder: Weigh 200g~300g W powder and 43g~55g aluminum alloy powder; 2. Sintering of porous tungsten skeleton: The tungsten powder weighed in step 1 and 3g~5g of aluminum alloy powder are mixed and placed in a ball mill to obtain an alloy mixed powder; the alloy mixed powder is placed in a graphite mold, and then the mold is placed in a spark plasma sintering furnace cavity, and a pressure of 10MPa~60MPa is applied under vacuum conditions for compaction, and then the temperature is increased to 800℃~1000℃ at a heating rate of 80℃ / min~100℃ / min, and then increased to 1200℃~1500℃ at a heating rate of 40℃ / min~50℃ / min, and finally spark plasma sintering is performed. After sintering, the mixture is cooled to room temperature with the furnace, and then demolded to obtain a porous tungsten skeleton; Step 2: The spark plasma sintering process is as follows: the vacuum degree is 10 -3 Pa, sintering time is 3 min~7 min, applied pressure is 10MPa~60MPa, sintering current is DC pulse current of 1000A-3000A, sintering power is 5kW~10kW; The ball milling process in step 2 is as follows: using a planetary ball mill, a ball-to-material ratio of 1: (5-25), a ball milling temperature of 30°C to 70°C, a ball milling speed of 100 rpm to 500 rpm, and a ball milling time of 4 h to 20 h; 3. Preparation of tungsten-infiltrated aluminum-dissipated heat-resistant composite materials by pressure infiltration The porous tungsten skeleton obtained in step 2 is placed in a pressure infiltration mold, and the mold is then placed in a heating furnace. The temperature of the heating furnace is raised from room temperature to 450°C to 650°C and kept warm for 5 minutes to 10 minutes to obtain a preheated tungsten skeleton; the remaining aluminum alloy powder weighed in step 1 is heated until melted to obtain molten aluminum alloy liquid; The molten aluminum alloy liquid is poured into the preheated tungsten skeleton in the mold, and a pressure of 90kN~150kN is applied by a press to make the molten aluminum alloy liquid infiltrate into the pores of the preheated tungsten skeleton; after the molten aluminum alloy liquid is completely infiltrated into the preheated tungsten skeleton preform, it is placed in the air to cool, and after cooling, the mold is demolded to obtain an ingot, that is, a tungsten-infiltrated aluminum dissipative heat-resistant composite material.

2. The method for preparing the tungsten-aluminized dissipative heat-protective composite material according to claim 1, characterized in that: The particle size of the W powder in step 1 is 10µm~100µm.

3. The method for preparing the tungsten-aluminized dissipative heat-protective composite material according to claim 1, characterized in that: The aluminum alloy powder in step 1 is pure aluminum alloy.

4. The method for preparing the tungsten-aluminized dissipative heat-protective composite material according to claim 3, characterized in that: The aluminum alloy is one of an Al-Si alloy, an Al-Si-Cu alloy, an Al-Si-Mg alloy, and an Al-Si-Cu-Mg alloy, or a combination thereof; the mass fraction of Si in the Al-Si alloy is 0.5%-25%; the mass fraction of Si in the Al-Si-Cu alloy is 0.5%-25%, and the mass fraction of Cu is 0.5%-53%; the mass fraction of Si in the Al-Si-Mg alloy is 0.5%-25%, and the mass fraction of Mg is 0.5%-38%; the mass fraction of Zn in the Al-Zn-Cu alloy is 0.5%-55%, and the mass fraction of Cu is 0.5%-53%; the mass fraction of Si in the Al-Si-Cu-Mg alloy is 0.5%-25%, the mass fraction of Cu is 0.5%-53%, and the mass fraction of Mg is 0.5%-38%.

5. The method for preparing the tungsten-aluminized dissipative heat-protective composite material according to claim 1, characterized in that: Step 1: Weigh 250g W powder and 55g aluminum alloy powder.

6. The method for preparing the tungsten-aluminized dissipative heat-protective composite material according to claim 1, characterized in that: Step 2: Place the mold in the cavity of the spark plasma sintering furnace, apply 30MPa pressure for compaction under vacuum conditions, then increase the temperature to 1000℃ at a heating rate of 100℃ / min, and then increase the temperature to 1500℃ at a heating rate of 50℃ / min. Finally, perform spark plasma sintering. After sintering, cool it to room temperature with the furnace, and then demold it to obtain a porous tungsten skeleton.

7. The method for preparing the tungsten-aluminized dissipative heat-protective composite material according to claim 1, characterized in that: Step 2: The spark plasma sintering process is as follows: the vacuum degree is 10 -3 Pa, the sintering time is 5 min, the applied pressure is 30 MPa, the sintering current is a DC pulse current of 2600 A, and the sintering power is 10 kW.

8. The method for preparing the tungsten-aluminized dissipative heat-protective composite material according to claim 1, characterized in that: The ball milling process in step 2 is as follows: using a planetary ball mill, a ball-to-material ratio of 1:10, a ball milling temperature of 40° C., a ball milling speed of 300 rpm, and a ball milling time of 10 h.

9. The method for preparing the tungsten-aluminized dissipative heat-protective composite material according to claim 1, characterized in that: Step 3: Place the mold in a heating furnace, raise the temperature of the heating furnace from room temperature to 500°C and keep it warm for 5 minutes.

10. The method for preparing the tungsten-aluminized dissipative heat-protective composite material according to claim 1, characterized in that: Step 3: Apply a pressure of 100 kN through a press to allow the molten aluminum alloy to infiltrate the pores of the preheated tungsten skeleton.

Images