Tungsten-rhenium-lanthanum-hafnium copper infiltration material and preparation method

Abstract

The invention discloses a preparation method of a tungsten-rhenium-lanthanum-hafnium copper infiltrated material. The preparation method comprises the following steps that 1, tungsten powder, rhenium powder, lanthanum powder and hafnium powder are selected; 2, tungsten powder, rhenium powder, lanthanum powder and hafnium powder are subjected to high-energy ball milling treatment; 3, the tungsten-rhenium-lanthanum-hafnium pre-alloyed powder obtained in the step 2 is loaded into a forming mold, a cold isostatic press is adopted for pressing forming, and a tungsten-rhenium-lanthanum-hafnium green body is obtained; 4, the tungsten-rhenium-lanthanum-hafnium green body is placed in a vacuum atmosphere sintering furnace to be sintered; 5, the sintered blank obtained in the step 4 is subjected to copper infiltration treatment in an infiltration furnace, and a tungsten-rhenium-lanthanum-hafnium copper infiltration material blank is obtained; and 6, the tungsten-rhenium-lanthanum-hafnium copper infiltrated material blank obtained in the step 5 is machined and subjected to flaw detection, and then the tungsten-rhenium-lanthanum-hafnium copper infiltrated material is obtained. According to the method, the problem that an existing tungsten infiltrated copper material is low in ablation resistance is solved. The invention also discloses the tungsten-rhenium-lanthanum-hafnium material prepared by the method.

Description

Technical Field

[0001] This invention belongs to the technical field of high-temperature resistant and ablation-resistant materials, specifically relating to tungsten-rhenium-lanthanum-hafnium copper-infiltrated materials, and also to a method for preparing such materials. Background Technology

[0002] Currently used high-temperature resistant and ablation-resistant materials mainly fall into two categories: tungsten-copper infiltrated materials and carbon / carbon-copper infiltrated materials. Tungsten-copper infiltrated materials are primarily used in high-overload applications, such as air-to-air missiles and surface-to-air missiles, while carbon / carbon-copper infiltrated materials are mainly used in large launch vehicle boosters. With the development of hypersonic vehicles and advanced rocket engines, hot-end components face the dual challenges of extreme ablation environments (>2500℃) and severe thermal shock loads. During long-term service, they have revealed bottleneck problems such as insufficient high-temperature strength, deterioration of ablation resistance, and synergistic failure of thermal ablation. Although traditional tungsten-copper infiltrated materials have excellent thermal conductivity (180–200 W / (m·K)), their high-temperature strength is severely degraded (strength <100 MPa at >1000℃), resulting in an ablation rate as high as 2.2 mg / s (oxyacetylene flame test conditions 3000℃ / 60s).

[0003] Currently, there are many patents for improving the ablation resistance of tungsten-copper infiltrating materials, such as the patent for strengthening the tungsten framework: CN202311319943A. This patent adds Re+HfC (W 64~93.9wt%, Re 1~25wt%, Cu 5~10wt%, HfC 0.1~1wt%) to the W-Cu infiltrating material. HfC is added in the form of second-phase particles, improving the material's oxidation resistance. However, due to the aggregation of HfC particles at grain boundaries, the improvement in ablation resistance is limited, with the ablation rate only decreasing to 1.2 mg / s. Current technologies do not involve carburizing or nitriding the tungsten framework to further enhance its ablation resistance, nor do they innovatively introduce rare earth catalysts to improve the carbonitriding effect. Summary of the Invention

[0004] The first objective of this invention is to provide a method for preparing tungsten-rhenium-lanthanum-hafnium copper-infiltrated materials, thereby improving the problem of low ablation resistance of existing tungsten-infiltrated copper materials.

[0005] A second objective of this invention is to provide a tungsten-rhenium-lanthanum-hafnium copper-infiltrated material.

[0006] The first technical solution adopted in this invention is a method for preparing tungsten-rhenium-lanthanum-hafnium copper-infiltrated materials, comprising the following steps:

[0007] Step 1: Select four powders: tungsten powder (W), rhenium powder (Re), lanthanum powder (La), and hafnium powder (Hf);

[0008] Step 2: High-energy ball milling is performed on four powders: tungsten powder, rhenium powder, lanthanum powder, and hafnium powder.

[0009] Step 3: The tungsten-rhenium-lanthanum-hafnium pre-alloy powder obtained in Step 2 is loaded into a molding die and pressed into shape using a cold isostatic press to obtain a tungsten-rhenium-lanthanum-hafnium green billet.

[0010] Step 4: Place the tungsten-rhenium-lanthanum-hafnium green billet in a vacuum / atmosphere sintering furnace for sintering treatment;

[0011] Step 5: The sintered billet obtained in Step 4 is subjected to copper infiltration treatment in a melting furnace to obtain a copper-infiltrated tungsten-rhenium-lanthanum-hafnium material billet.

[0012] Step 6: The tungsten-rhenium-lanthanum-hafnium copper-infiltrated material blank obtained in Step 5 is machined and inspected to obtain the tungsten-rhenium-lanthanum-hafnium copper-infiltrated material.

[0013] The invention is further characterized in that:

[0014] In step 1: the laser particle size range D50 of tungsten powder and rhenium powder is 3μm to 10μm, and the laser particle size range D50 of lanthanum powder and hafnium powder is 50nm to 500nm;

[0015] In step 1, the ratio of the four raw material powders is as follows: rhenium powder 5wt% to 10wt%, lanthanum powder 0.3wt% to 0.8wt%, hafnium powder 0.1wt% to 1.5wt%, and the balance is tungsten powder.

[0016] Step 2 specifically involves: first, loading the tungsten powder and rhenium powder obtained in Step 1 into a high-energy ball mill jar in a vacuum glove box to form tungsten-rhenium pre-alloy powder; then, loading the lanthanum powder and hafnium powder into the high-energy ball mill jar in a vacuum glove box to form lanthanum-hafnium pre-alloy powder; finally, loading the tungsten-rhenium pre-alloy powder and lanthanum-hafnium pre-alloy powder into the high-energy ball mill jar in a vacuum glove box to form tungsten-rhenium-lanthanum-hafnium pre-alloy powder. During all three ball milling processes, the vacuum glove box is under Ar protection throughout, and the high-energy ball mill jar is also under Ar protection. The ball-to-material ratio is 10:1 to 20:1, the rotation speed is 100 rpm to 500 rpm, the milling time is 1 hour to 5 hours, and the milling is followed by a resting period of 1 hour to 5 hours. The milling balls are tungsten carbide balls. The Ar purity used is 99.999%.

[0017] Step 3 specifically involves: loading tungsten, rhenium, lanthanum, and hafnium powder into a molding sleeve, and using a cold isostatic press to hold the pressure at 100MPa to 200MPa for 30 to 120 minutes to obtain a cold isostatic pressed tungsten, rhenium, lanthanum, and hafnium green billet.

[0018] In step 4, the tungsten-rhenium-lanthanum-hafnium green billet is processed in four stages in a vacuum / atmosphere sintering furnace, specifically as follows:

[0019] The first stage is sintering in an argon atmosphere. The specific process conditions are: sintering atmosphere is Ar, vacuum degree is 10. -1 Pa~10 -3 Pa, the heating rate is 3℃ / min~8℃ / min, and the temperature is increased to the nitriding temperature, where the nitriding temperature is 800℃~1000℃;

[0020] The second stage is argon + ammonia nitriding sintering. The specific process is as follows: when the furnace temperature reaches the nitriding temperature of 800℃~1000℃, the holding time begins and is 1h~3h. NH3 is introduced simultaneously at a flow rate of 2L / min·m³. 2 ~5L / min·m 2 The gas flow rate is increased until the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar = 1:1~5. During the NH3 introduction process, the NH3 concentration is monitored online every 10 min to 30 min using a laser gas analyzer. If the deviation is >2 vol% to 8 vol%, the gas flow rate is adjusted to ensure that the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar = 1:1~5. After nitriding sintering is completed, Ar is continuously introduced into the furnace and NH3 is discharged. At the same time, the NH3 content is detected online using a laser gas analyzer until the NH3 content is <1 ppm for 30 consecutive minutes. Then, the temperature is raised to the carburizing temperature, which is 1000℃ to 1200℃.

[0021] The third stage is argon + acetylene carburizing and sintering. The specific process is as follows: when the furnace temperature reaches the carburizing temperature of 1000℃~1200℃, the holding time begins and is 1h~3h. During the holding time, C2H2 is introduced at a gas flow rate of 3L / min·m 2 ~7L / min·m 2 The process continues until the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar = 1:1~5. During the C2H2 introduction process, the C2H2 concentration is monitored online every 10 min to 30 min using a laser gas analyzer. If the deviation is >1 vol% to 5 vol%, the gas flow rate is automatically adjusted to ensure that the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar = 1:1~5. After carburizing and sintering, Ar is continuously introduced into the furnace while C2H2 is discharged. At the same time, the C2H2 content is detected online using a laser gas analyzer. After the C2H2 content is <1 ppm for 30 consecutive minutes, the Ar introduction is stopped and H2 is introduced. The Ar content is detected online using a laser gas analyzer. After the Ar content is <1 ppm for 30 consecutive minutes, the temperature is raised to the skeleton sintering temperature, which is 1800℃ to 2000℃.

[0022] The fourth stage is skeleton sintering. The specific process conditions are as follows: the skeleton sintering temperature is 1800℃~2000℃, the sintering atmosphere is H2, and when the furnace temperature reaches the skeleton sintering temperature, the heat preservation begins and the heat preservation time is 2h~6h. After the heat preservation is completed, the skeleton is cooled with the furnace. In the fourth stage, the relative density of the skeleton is controlled to be 72%~87% to reserve pores for Cu melting and infiltration.

[0023] Step 5 specifically involves placing the sintered billet inside a graphite boat, ensuring that the length, width, and height of the graphite boat can accommodate the billet. The volume of the graphite boat should be 1.5 times the volume of the sintered billet, and its height should be 50mm higher than the height of the sintered billet. Then, place the copper block on top of the sintered billet, ensuring that the melted copper block completely covers the billet. The melting and infiltration process conditions are: vacuum degree 10... -1 Pa~10 -3 Pa, the melting and infiltration temperature is 1000℃~1600℃, the holding time is 2h~6h, and the sintering atmosphere is Ar; in step 5, the Cu content in the obtained melting and infiltration blank is 5wt%~13wt%.

[0024] Step 6 specifically involves: performing surface polishing on the obtained melt-infiltrated blank to achieve a surface roughness Ra of 0.2 μm to 3.2 μm. After the polishing, water immersion ultrasonic testing is performed, and the testing is carried out in accordance with the GJB2299A-2005 standard.

[0025] The second technical solution adopted in this invention is a tungsten-rhenium-lanthanum-hafnium copper-infiltrated material, which is prepared by the above method.

[0026] The beneficial effects of this invention are:

[0027] The tungsten-rhenium-lanthanum-hafnium copper-infiltrated material prepared by the method of this invention has a synergistic structure of "nitrogen-carbon co-diffusion + molten copper infiltration". This tungsten-rhenium-lanthanum-hafnium copper-infiltrated material can further improve its ablation resistance by introducing reinforcing phases through nitriding and carburizing on the basis of traditional tungsten copper infiltration. Specifically, tungsten-rhenium-lanthanum-hafnium undergoes cold isostatic pressing, nitriding sintering, carburizing sintering, and hydrogen sintering to become a porous framework material with interconnected pores. Simultaneously, the framework properties are strengthened after nitriding and carburizing. Rare earth lanthanum catalyzes carbon-nitrogen co-diffusion (forming reinforcing phases WN, ReN, HfC, and LaC). x The matrix of this invention is a tungsten-rhenium-lanthanum-hafnium alloy. The pores formed by the matrix are filled with copper after capillary adsorption and melt infiltration. The matrix composition is a W-Re-La-Hf alloy (Re 5wt%–10wt%, La 0.3wt%–0.8wt%, Hf 0.1wt%–1.5wt%, balance W), which significantly improves the ablation resistance of the tungsten-rhenium-lanthanum-hafnium copper-infiltrated material. Furthermore, this invention innovatively optimizes the preparation process. The addition of lanthanum catalyzes the nitriding and carburizing of the matrix, while the addition of hafnium forms a hafnium carbide reinforcing phase and adsorbs free oxygen. The alloy undergoes a two-stage rare-earth catalytic nitriding and carburizing process to strengthen the matrix. By using nitriding-carburizing and melt infiltration of copper to enhance the ablation resistance of the tungsten-rhenium-lanthanum-hafnium copper-infiltrated alloy, it is suitable for components subjected to extreme heat loads, such as aerospace engine nozzles and nuclear fusion devices. Attached Figure Description

[0028] Figure 1 The cross-sectional microstructure of WReHfLa-7Cu obtained in Example 1;

[0029] Figure 2 The image shows the energy spectrum of WReHfLa-7Cu obtained in Example 1. Detailed Implementation

[0030] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings.

[0031] This invention provides a method for preparing tungsten-rhenium-lanthanum-hafnium copper-doped materials, comprising the following steps:

[0032] Step 1: Select four types of powders: tungsten powder, rhenium powder, lanthanum powder, and hafnium powder;

[0033] In step 1: the laser particle size range D50 of tungsten powder and rhenium powder is 3μm to 10μm, and the laser particle size range D50 of lanthanum powder and hafnium powder is 50nm to 500nm;

[0034] In step 1, the ratio of the four raw material powders is as follows: rhenium powder 5wt% to 10wt%, lanthanum powder 0.3wt% to 0.8wt%, hafnium powder 0.1wt% to 0.5wt%, and the balance is tungsten powder.

[0035] Step 2: High-energy ball milling is performed on four powders: tungsten powder, rhenium powder, lanthanum powder, and hafnium powder.

[0036] Step 2 specifically involves: W (density 19.25 g / cm³) 3 Re (density is 21.04 g / cm³) 3 The tungsten powder, rhenium powder (density 13.31 g / cm³), and lanthanum powder (density 6.15 g / cm³) have large density differences. To reduce stratification, the tungsten powder and rhenium powder obtained in step 1 are first placed in a high-energy ball mill jar in a vacuum glove box to form tungsten-rhenium pre-alloy powder. Then, lanthanum powder and hafnium powder are placed in a high-energy ball mill jar in a vacuum glove box to form lanthanum-hafnium pre-alloy powder. Finally, the tungsten-rhenium pre-alloy powder and lanthanum-hafnium pre-alloy powder are placed in a high-energy ball mill jar in a vacuum glove box. The grinding jar forms a tungsten-rhenium-lanthanum-hafnium pre-alloyed powder. During the three ball milling processes, the vacuum glove box is used for full Ar protection (Ar purity 99.999%), the high-energy ball mill jar is filled with Ar for protection (Ar purity 99.999%), the ball-to-material ratio is 10:1 to 20:1, the rotation speed is 100 rpm to 500 rpm, the ball milling time is 1 h to 5 h, and the ball milling is stopped for 1 h to 5 h after the ball milling is completed. The grinding balls are tungsten carbide balls to avoid the use of steel balls, which would introduce impurities such as Fe.

[0037] Step 3: The tungsten-rhenium-lanthanum-hafnium pre-alloy powder obtained in Step 2 is loaded into a molding die and pressed into shape using a cold isostatic press to obtain a tungsten-rhenium-lanthanum-hafnium green billet.

[0038] Step 3 specifically involves: loading tungsten, rhenium, lanthanum, and hafnium powder into a molding sleeve, and using a cold isostatic press to hold the pressure at 100MPa to 200MPa for 30 to 120 minutes to obtain a cold isostatic pressed tungsten, rhenium, lanthanum, and hafnium green billet.

[0039] Step 4: Place the tungsten-rhenium-lanthanum-hafnium green billet in a vacuum atmosphere sintering furnace for sintering treatment;

[0040] In step 4, the tungsten-rhenium-lanthanum-hafnium green billet is processed in a vacuum / atmosphere sintering furnace in four stages: argon atmosphere sintering, argon + ammonia nitriding sintering, argon + acetylene carburizing sintering, and skeleton sintering, specifically:

[0041] The first stage is sintering in an argon atmosphere. The specific process conditions are: sintering atmosphere is Ar (Ar purity 99.999%), vacuum degree 10. -1 Pa~10 -3 Pa, the heating rate is 3℃ / min~8℃ / min, and the temperature is increased to the nitriding temperature, where the nitriding temperature is 800℃~1000℃;

[0042] The second stage is argon + ammonia nitriding sintering. The specific process conditions are: nitriding temperature of 800℃~1000℃, holding time of 1h~3h, and the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar=1:1~5.

[0043] The specific process flow for argon + ammonia nitriding sintering is as follows: When the furnace temperature reaches the nitriding temperature of 800℃~1000℃, the holding time begins for 1h~3h. Simultaneously, NH3 (NH3 purity 99.999%) is introduced at a flow rate of 2L / min·m2~5L / min·m2 until the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar = 1:1~5. As the NH3 cracking process occurs, the NH3 concentration in the furnace will constantly change. During the NH3 introduction process, the concentration will be adjusted every 10m... The concentration of NH3 is monitored online using a laser gas analyzer for 30 minutes. If the deviation is >2 vol% to 8 vol%, the gas flow rate is automatically adjusted to ensure that the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar = 1:1 to 5. After nitriding sintering is completed, Ar is continuously introduced into the furnace and NH3 is discharged. At the same time, the NH3 content is detected online using a laser gas analyzer until the NH3 content is <1 ppm for 30 consecutive minutes. Then, the temperature is raised to the carburizing temperature, which is 1000℃ to 1200℃.

[0044] The third stage is argon + acetylene carburizing sintering. The specific process conditions are: carburizing temperature of 1000℃~1200℃, holding time of 1h~3h, and the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar=1:1~5.

[0045] The specific process flow for argon + acetylene carburizing sintering is as follows: When the furnace temperature reaches the carburizing temperature of 1000℃~1200℃, the temperature is held for 1h~3h. Simultaneously, C2H2 (99.9% purity) is introduced at a flow rate of 3L / min·m2~7L / min·m2 until the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar = 1:1~5. As the C2H2 cracking process occurs, the C2H2 concentration in the furnace will constantly change. During the C2H2 introduction process, the C2H2 concentration is monitored online every 10min~30min using a laser gas analyzer. When the deviation is >1vol% to 5vol%, the gas flow rate is automatically adjusted to ensure that the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar = 1:1 to 5. After carburizing and sintering, Ar is continuously introduced into the furnace and C2H2 is discharged. At the same time, the C2H2 content is detected online using a laser gas analyzer. After the C2H2 content is <1ppm for 30 consecutive minutes, the Ar is stopped and H2 is introduced. The Ar content is detected online using a laser gas analyzer. After the Ar content is <1ppm for 30 consecutive minutes, the temperature is raised to the skeleton sintering temperature, which is 1800℃ to 2000℃.

[0046] The fourth stage is skeleton sintering. The specific process conditions are as follows: the skeleton sintering temperature is 1800℃~2000℃, the sintering atmosphere is H2 (H2 purity 99.999%), and when the furnace temperature reaches the skeleton sintering temperature, the holding time begins and is 2h~6h. After the holding time is completed, the skeleton is cooled with the furnace. In the fourth stage, the relative density of the skeleton is controlled at 72%~87% to reserve pores for Cu melting and infiltration.

[0047] Step 5: The sintered billet obtained in Step 4 is subjected to copper infiltration treatment in a melting furnace to obtain a copper-infiltrated tungsten-rhenium-lanthanum-hafnium material billet.

[0048] Step 5 specifically involves placing the sintered billet inside a graphite boat, ensuring that the length, width, and height of the graphite boat can accommodate the billet. The volume of the graphite boat should be 1.5 times the volume of the sintered billet, and its height should be 50mm higher than the height of the sintered billet. Then, place the copper block on top of the sintered billet, ensuring that the melted copper block completely covers the billet. The melting and infiltration process conditions are: vacuum degree 10... -1 Pa~10 -3 Pa, the melting and infiltration temperature is 1000℃~1600℃, the holding time is 2h~6h, and the sintering atmosphere is Ar; in step 5, the Cu content in the obtained melting and infiltration blank is 5wt%~13wt%.

[0049] Step 6: The tungsten-rhenium-lanthanum-hafnium copper-infiltrated material blank obtained in Step 5 is machined and inspected to obtain the tungsten-rhenium-lanthanum-hafnium copper-infiltrated material.

[0050] Step 6 specifically involves: performing surface light treatment on the obtained melt-infiltrated blank to achieve a surface roughness Ra of 0.2 μm to 3.2 μm, followed by water immersion ultrasonic testing, and performing the testing according to the GJB2299A-2005 standard.

[0051] The present invention also provides a tungsten-rhenium-lanthanum-hafnium copper-infiltrated material, which is prepared by the above method.

[0052] Example 1

[0053] Step 1: Select four powders: tungsten powder D50: 3μm, rhenium powder D50: 3μm, lanthanum powder D50: 50nm, and hafnium powder D50: 50nm. The ratio of the four powders is Re 5wt%, La 0.3wt%, Hf 0.1wt%, and the remainder is W.

[0054] Step 2: The tungsten powder and rhenium powder obtained in Step 1 are loaded into a high-energy ball mill jar in a vacuum glove box to form tungsten-rhenium pre-alloy powder. Then, lanthanum powder and hafnium powder are loaded into the high-energy ball mill jar in a vacuum glove box to form lanthanum-hafnium pre-alloy powder. Finally, the tungsten-rhenium pre-alloy powder and lanthanum-hafnium pre-alloy powder are loaded into the high-energy ball mill jar in a vacuum glove box to form tungsten-rhenium-lanthanum-hafnium pre-alloy powder. During the three ball milling processes, the vacuum glove box is protected with Ar throughout (Ar purity 99.999%), the high-energy ball mill jar is filled with Ar for protection (Ar purity 99.999%), the ball-to-material ratio is 10:1, the rotation speed is 100 rpm, the ball milling time is 1 hour, and the ball milling is stopped for 1 hour after the ball milling is completed. The ball milling balls are tungsten carbide balls to avoid using steel balls, which would introduce impurities such as Fe.

[0055] Step 3: The tungsten-rhenium-lanthanum-hafnium pre-alloy powder obtained in Step 2 is loaded into a molding sleeve and held at 100 MPa for 80 minutes using a cold isostatic press to obtain a cold isostatic pressed tungsten-rhenium-lanthanum-hafnium green billet.

[0056] Step 4: The tungsten-rhenium-lanthanum-hafnium green billet is processed in a vacuum / atmosphere sintering furnace in four stages, specifically:

[0057] The first stage is sintering in an argon atmosphere. The specific process conditions are: sintering atmosphere is Ar (Ar purity 99.999%), vacuum degree 10. -3 Pa, heating rate is 3℃ / min, heating to the nitriding temperature, where the nitriding temperature is 900℃;

[0058] The second stage is argon + ammonia nitriding sintering. The specific process is as follows: when the furnace temperature reaches the nitriding temperature of 900℃, the holding time begins and lasts for 3 hours. NH3 is introduced simultaneously with the holding time at a flow rate of 5 L / min·m³. 2The gas flow rate is adjusted until the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar = 1:3. During the NH3 introduction process, the NH3 concentration is monitored online every 10 minutes using a laser gas analyzer. If the deviation is >2 vol%, the gas flow rate is adjusted to ensure that the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar = 1:3. After nitriding sintering is completed, Ar is continuously introduced into the furnace and NH3 is discharged. At the same time, the NH3 content is detected online using a laser gas analyzer until the NH3 content is <1 ppm for 30 consecutive minutes. Then, the temperature is raised to the carburizing temperature, which is 1050℃.

[0059] The third stage is argon + acetylene carburizing sintering. The specific process is as follows: when the furnace temperature reaches the carburizing temperature of 1050℃, the holding time begins and lasts for 3 hours. Simultaneously, C2H2 is introduced at a flow rate of 7 L / min·m2. 2 The process continues until the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar = 1:4. During the C2H2 introduction process, the C2H2 concentration is monitored online every 10 minutes using a laser gas analyzer. If the deviation is >1 vol%, the gas flow rate is automatically adjusted to ensure that the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar = 1:4. After carburizing and sintering, Ar is continuously introduced into the furnace while C2H2 is discharged. At the same time, the C2H2 content is detected online using a laser gas analyzer until the C2H2 content is <1 ppm for 30 consecutive minutes. Then, the Ar introduction is stopped and H2 is introduced. The Ar content is detected online using a laser gas analyzer until the Ar content is <1 ppm for 30 consecutive minutes. Then, the temperature is raised to the skeleton sintering temperature, which is 1800℃.

[0060] The fourth stage is skeleton sintering. The specific process conditions are as follows: the skeleton sintering temperature is 1800℃, the sintering atmosphere is H2 (H2 purity 99.999%), and the heat holding begins when the furnace temperature reaches the skeleton sintering temperature. The heat holding time is 6 hours, and the furnace is cooled after the heat holding is completed. In the fourth stage, the relative density of the skeleton is controlled at 84% to reserve pores for Cu melting and infiltration.

[0061] Step 5: Place the sintered billet obtained in Step 4 inside a graphite boat, and place the copper block on top of the sintered billet, ensuring that the copper block, after melting, can completely bury the sintered billet. The melting and infiltration process is as follows: vacuum degree 10. -1 Pa, the melting and infiltration temperature is 1200℃, the holding time is 6h, and the sintering atmosphere is Ar (Ar purity 99.999%); in step 5, the Cu content in the obtained melting and infiltration blank is 7wt%.

[0062] Step 6: The tungsten-rhenium-lanthanum-hafnium copper-infiltrated material blank obtained in Step 5 is subjected to light treatment to achieve a surface roughness Ra = 3.2 μm. After treatment, water immersion ultrasonic testing is performed according to the GJB2299A-2005 standard. After passing the test, the tungsten-rhenium-lanthanum-hafnium copper-infiltrated material is obtained.

[0063] Table 1 Comparison of Performance Tests of the Invention Material and Traditional Materials

[0064]

[0065] The WReHfLa-7Cu material prepared in this invention improves the high-temperature mechanical properties of the W framework by introducing Re and Hf elements, and catalyzes the nitriding and carburizing of the framework by introducing La elements. The W, Re, Hf, and La elements form WN, ReN, HfC, and LaC alloys. x This invention achieves second-phase reinforcement of the framework, improving the ablation resistance of the material. The ablation resistance of W-Cu mainly depends on the ablation resistance of the framework. Under high temperature, high pressure, and metal particle erosion environments, Cu, due to its low melting point, melts first, undergoing solid-liquid-gas phase transformation. The W framework after Cu volatilization plays a role in supporting the structural stability of the material. With prolonged ablation time, the W framework is gradually oxidized, eroded, and eventually fails. This invention strengthens the W framework while employing rare-earth La-catalyzed nitriding and carburizing to further enhance the framework.

[0066] Figure 1 Photographs of the cross-sectional morphology of WReHfLa-7Cu, from Figure 1 As can be seen, after nitriding, carburizing and high-temperature sintering, W powder, Re powder, Hf powder and La powder form sintering necks between particles and have a through-hole structure. During the melting and infiltration stage, copper fills the pores by capillary adsorption. The gray irregular block structure in the figure is WReHfLa alloy particles, and the bright white irregular strips are Cu filling the pores. Figure 2 The energy dispersive spectroscopy (EDS) image of WReHfLa-7Cu shows that W, Re, Hf, La, and Cu are uniformly distributed. Table 1 compares the ablation resistance and thermal shock resistance of WReHfLa-7Cu and W-7Cu materials prepared in Example 1. Under oxyacetylene ablation at 2800℃, the mass loss rate of WReHfLa-7Cu was 0.75 mg / s, while that of W-7Cu was 2.2 mg / s. The ablation resistance of WReHfLa-7Cu was 66% higher than that of W-7Cu. Under water quenching from room temperature to 1200℃, WReHfLa-7Cu cracked after 50 thermal shock cycles, while W-7Cu cracked after 15 thermal shock cycles. The thermal shock resistance of WReHfLa-7Cu was 233% higher than that of W-7Cu.

[0067] Example 2

[0068] Step 1: Select four powders: tungsten powder D50: 10μm, rhenium powder D50: 10μm, lanthanum powder D50: 500nm, and hafnium powder D50: 500nm. The ratio of the four powders is Re 10wt%, La 0.8wt%, Hf 0.5wt%, and the remainder is W.

[0069] Step 2: First, the tungsten powder and rhenium powder obtained in Step 1 are loaded into a high-energy ball mill jar in a vacuum glove box to form tungsten-rhenium pre-alloy powder. Then, lanthanum powder and hafnium powder are loaded into the high-energy ball mill jar in a vacuum glove box to form lanthanum-hafnium pre-alloy powder. Finally, the tungsten-rhenium pre-alloy powder and lanthanum-hafnium pre-alloy powder are loaded into the high-energy ball mill jar in a vacuum glove box to form tungsten-rhenium-lanthanum-hafnium pre-alloy powder. During the three ball milling processes, the vacuum glove box is protected with Ar throughout, and the high-energy ball mill jar is filled with Ar for protection. The ball-to-material ratio is 10:1, the rotation speed is 100 rpm, the ball milling time is 1 hour, and the ball milling time is 1 hour after the ball milling is completed. The ball milling balls are tungsten carbide balls. The purity of the Ar used is 99.999%.

[0070] Step 3: Load tungsten, rhenium, lanthanum, and hafnium powder into a molding sleeve, and use a cold isostatic press to hold the pressure at 100 MPa for 30 minutes to obtain a cold isostatic pressed tungsten, rhenium, lanthanum, and hafnium green billet.

[0071] Step 4: The tungsten-rhenium-lanthanum-hafnium green billet is processed in a vacuum / atmosphere sintering furnace in four stages, specifically:

[0072] The first stage is sintering in an argon atmosphere. The specific process conditions are: sintering atmosphere is Ar, vacuum degree is 10. -1 Pa, heating rate is 3℃ / min, heating to the nitriding temperature, where the nitriding temperature is 800℃;

[0073] The second stage is argon + ammonia nitriding sintering. The specific process is as follows: when the furnace temperature reaches the nitriding temperature of 800℃, the holding time begins and is 1 hour. NH3 is introduced simultaneously at a flow rate of 2 L / min·m³. 2 The gas flow rate is adjusted until the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar = 1:1. During the NH3 introduction process, the NH3 concentration is monitored online every 10 minutes using a laser gas analyzer. If the deviation is >2 vol%, the gas flow rate is adjusted to ensure that the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar = 1:1. After nitriding sintering is completed, Ar is continuously introduced into the furnace and NH3 is discharged. At the same time, the NH3 content is detected online using a laser gas analyzer until the NH3 content is <1 ppm for 30 consecutive minutes. Then, the temperature is raised to the carburizing temperature, which is 1000℃.

[0074] The third stage is argon + acetylene carburizing sintering. The specific process is as follows: when the furnace temperature reaches the carburizing temperature of 1000℃, the holding time begins and is 1 hour. Simultaneously, C2H2 is introduced at a flow rate of 3 L / min·m³.2 The process continues until the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar = 1:1. During the C2H2 introduction process, the C2H2 concentration is monitored online every 10 minutes using a laser gas analyzer. If the deviation is >1 vol%, the gas flow rate is automatically adjusted to ensure that the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar = 1:1. After carburizing and sintering, Ar is continuously introduced into the furnace while C2H2 is discharged. At the same time, the C2H2 content is detected online using a laser gas analyzer until the C2H2 content is <1 ppm for 30 consecutive minutes. Then, the Ar introduction is stopped and H2 is introduced. The Ar content is detected online using a laser gas analyzer until the Ar content is <1 ppm for 30 consecutive minutes. Then, the temperature is raised to the skeleton sintering temperature, which is 1950℃.

[0075] The fourth stage is skeleton sintering. The specific process conditions are as follows: the skeleton sintering temperature is 1950℃, the sintering atmosphere is H2, and the heat preservation begins when the furnace temperature reaches the skeleton sintering temperature. The heat preservation time is 2 hours, and the skeleton is cooled with the furnace after the heat preservation is completed. In the fourth stage, the relative density of the skeleton is controlled at 73% to reserve pores for Cu melting and infiltration.

[0076] Step 5: Place the sintered billet inside the graphite boat, ensuring that the length, width, and height of the graphite boat can accommodate the billet. The volume of the graphite boat should be 1.5 times the volume of the sintered billet, and its height should be 50mm higher than the billet's height. Place the copper block on top of the billet, ensuring that the melting copper block completely covers the billet. The melting and infiltration process conditions are: vacuum degree 10. -1 Pa, the melting and infiltration temperature is 1000℃, the holding time is 2h, and the sintering atmosphere is Ar; in step 5, the Cu content in the obtained melting and infiltration blank is 13wt%.

[0077] Step 6: Perform surface polishing on the obtained melt-infiltrated blank to achieve a surface roughness Ra = 0.2 μm. After the treatment, perform water immersion ultrasonic testing according to the GJB2299A-2005 standard.

[0078] Example 3

[0079] Step 1: Select four powders: tungsten powder D50: 3μm, rhenium powder D50: 3μm, lanthanum powder D50: 50nm, and hafnium powder D50: 50nm. The ratio of the four powders is Re 5wt%, La 0.3wt%, Hf 0.1wt%, and the remainder is W.

[0080] Step 2: First, the tungsten powder and rhenium powder obtained in Step 1 are loaded into a high-energy ball mill jar in a vacuum glove box to form tungsten-rhenium pre-alloy powder. Then, lanthanum powder and hafnium powder are loaded into the high-energy ball mill jar in a vacuum glove box to form lanthanum-hafnium pre-alloy powder. Finally, the tungsten-rhenium pre-alloy powder and lanthanum-hafnium pre-alloy powder are loaded into the high-energy ball mill jar in a vacuum glove box to form tungsten-rhenium-lanthanum-hafnium pre-alloy powder. During the three ball milling processes, the vacuum glove box is protected with Ar throughout, and the high-energy ball mill jar is filled with Ar for protection. The ball-to-material ratio is 20:1, the rotation speed is 500 rpm, the ball milling time is 5 hours, and the ball milling time is 5 hours after the ball milling is completed. The ball milling balls are tungsten carbide balls. The purity of the Ar used is 99.999%.

[0081] Step 3: Load tungsten, rhenium, lanthanum, and hafnium powder into a molding sleeve, and use a cold isostatic press to hold the pressure at 200 MPa for 120 minutes to obtain a cold isostatic pressed tungsten, rhenium, lanthanum, and hafnium green billet.

[0082] Step 4: The tungsten-rhenium-lanthanum-hafnium green billet is processed in a vacuum / atmosphere sintering furnace in four stages, specifically:

[0083] The first stage is sintering in an argon atmosphere. The specific process conditions are: sintering atmosphere is Ar, vacuum degree is 10. -3 Pa, heating rate is 8℃ / min, heating to the nitriding temperature, where the nitriding temperature is 1000℃;

[0084] The second stage is argon + ammonia nitriding sintering. The specific process is as follows: when the furnace temperature reaches the nitriding temperature of 1000℃, the holding time begins and lasts for 3 hours. NH3 is introduced simultaneously at a flow rate of 5 L / min·m³. 2 The gas flow rate is adjusted until the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar = 1:5. During the NH3 introduction process, the NH3 concentration is monitored online every 30 minutes using a laser gas analyzer. If the deviation is >8 vol%, the gas flow rate is adjusted to ensure that the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar = 1:5. After nitriding sintering is completed, Ar is continuously introduced into the furnace and NH3 is discharged. At the same time, the NH3 content is detected online using a laser gas analyzer until the NH3 content is <1 ppm for 30 consecutive minutes. Then, the temperature is raised to the carburizing temperature, which is 1200℃.

[0085] The third stage is argon + acetylene carburizing sintering. The specific process is as follows: when the furnace temperature reaches the carburizing temperature of 1200℃, the holding time begins and is 3 hours. During the holding time, C2H2 is introduced at a gas flow rate of 7 L / min·m 2The process continues until the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar = 1:5. During the C2H2 introduction process, the C2H2 concentration is monitored online every 30 minutes using a laser gas analyzer. If the deviation is >5 vol%, the gas flow rate is automatically adjusted to ensure that the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar = 1:5. After carburizing and sintering, Ar is continuously introduced into the furnace while C2H2 is discharged. At the same time, the C2H2 content is detected online using a laser gas analyzer until the C2H2 content is <1 ppm for 30 consecutive minutes. Then, the Ar introduction is stopped and H2 is introduced. The Ar content is detected online using a laser gas analyzer until the Ar content is <1 ppm for 30 consecutive minutes. Then, the temperature is raised to the skeleton sintering temperature, which is 1850℃.

[0086] The fourth stage is skeleton sintering. The specific process conditions are as follows: the skeleton sintering temperature is 1850℃, the sintering atmosphere is H2, and the heat preservation begins when the furnace temperature reaches the skeleton sintering temperature. The heat preservation time is 6 hours, and the skeleton is cooled with the furnace after the heat preservation is completed. In the fourth stage, the relative density of the skeleton is controlled at 79% to reserve pores for Cu melting and infiltration.

[0087] Step 5: Place the sintered billet inside the graphite boat, ensuring that the length, width, and height of the graphite boat can accommodate the billet. The volume of the graphite boat should be 1.5 times the volume of the sintered billet, and its height should be 50mm higher than the billet's height. Place the copper block on top of the billet, ensuring that the melting copper block completely covers the billet. The melting and infiltration process conditions are: vacuum degree 10. -3 Pa, the melting and infiltration temperature is 1600℃, the holding time is 6h, and the sintering atmosphere is Ar; in step 5, the Cu content in the obtained melting and infiltration blank is 11wt%.

[0088] Step 6: Perform surface polishing on the obtained melt-infiltrated blank to achieve a surface roughness Ra = 3.2 μm. After the treatment, perform water immersion ultrasonic testing according to the GJB2299A-2005 standard.

[0089] Example 4

[0090] Step 1: Select four powders: tungsten powder with a D50 of 5μm, rhenium powder with a D50 of 5μm, lanthanum powder with a D50 of 100nm, and hafnium powder with a D50 of 100nm. The ratio of the four powders is Re 8wt%, La 0.5wt%, Hf 1wt%, and the remainder is W.

[0091] Step 2: First, the tungsten powder and rhenium powder obtained in Step 1 are loaded into a high-energy ball mill jar in a vacuum glove box to form tungsten-rhenium pre-alloy powder. Then, lanthanum powder and hafnium powder are loaded into the high-energy ball mill jar in a vacuum glove box to form lanthanum-hafnium pre-alloy powder. Finally, the tungsten-rhenium pre-alloy powder and lanthanum-hafnium pre-alloy powder are loaded into the high-energy ball mill jar in a vacuum glove box to form tungsten-rhenium-lanthanum-hafnium pre-alloy powder. During the three ball milling processes, the vacuum glove box is protected with Ar throughout, and the high-energy ball mill jar is filled with Ar for protection. The ball-to-material ratio is 15:1, the rotation speed is 300 rpm, the ball milling time is 3 hours, and the ball milling time is 3 hours after the ball milling is completed. The ball milling balls are tungsten carbide balls. The purity of the Ar used is 99.999%.

[0092] Step 3: Load tungsten, rhenium, lanthanum, and hafnium powder into a molding sleeve, and use a cold isostatic press to hold the pressure at 150 MPa for 100 min to obtain a cold isostatic pressed tungsten, rhenium, lanthanum, and hafnium green billet.

[0093] Step 4: The tungsten-rhenium-lanthanum-hafnium green billet is processed in a vacuum / atmosphere sintering furnace in four stages, specifically:

[0094] The first stage is sintering in an argon atmosphere. The specific process conditions are: sintering atmosphere is Ar, vacuum degree is 10. -1 Pa, heating rate is 5℃ / min, heating to the nitriding temperature, where the nitriding temperature is 900℃;

[0095] The second stage is argon + ammonia nitriding sintering. The specific process is as follows: when the furnace temperature reaches the nitriding temperature of 900℃, the holding time begins and is 1h to 3h. NH3 is introduced simultaneously with the holding time at a flow rate of 3L / min·m³. 2 The gas flow rate is adjusted until the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar = 1:3. During the NH3 introduction process, the NH3 concentration is monitored online every 20 minutes using a laser gas analyzer. If the deviation is >5 vol%, the gas flow rate is adjusted to ensure that the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar = 1:3. After nitriding sintering is completed, Ar is continuously introduced into the furnace and NH3 is discharged. At the same time, the NH3 content is detected online using a laser gas analyzer until the NH3 content is <1 ppm for 30 consecutive minutes. Then, the temperature is raised to the carburizing temperature, which is 1100℃.

[0096] The third stage is argon + acetylene carburizing sintering. The specific process is as follows: when the furnace temperature reaches the carburizing temperature of 1100℃, the holding time begins and lasts for 2 seconds. Simultaneously, C2H2 is introduced at a flow rate of 5 L / min·m³. 2The process continues until the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar = 1:3. During the C2H2 introduction process, the C2H2 concentration is monitored online every 20 minutes using a laser gas analyzer. If the deviation is >3 vol%, the gas flow rate is automatically adjusted to ensure that the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar = 1:3. After carburizing and sintering, Ar is continuously introduced into the furnace while C2H2 is discharged. At the same time, the C2H2 content is detected online using a laser gas analyzer until the C2H2 content is <1 ppm for 30 consecutive minutes. Then, the Ar introduction is stopped and H2 is introduced. The Ar content is detected online using a laser gas analyzer until the Ar content is <1 ppm for 30 consecutive minutes. Then, the temperature is raised to the skeleton sintering temperature, which is 1900℃.

[0097] The fourth stage is skeleton sintering. The specific process conditions are as follows: the skeleton sintering temperature is 1900℃, the sintering atmosphere is H2, and the heat preservation begins when the furnace temperature reaches the skeleton sintering temperature. The heat preservation time is 5h, and the skeleton is cooled with the furnace after the heat preservation is completed. In the fourth stage, the relative density of the skeleton is controlled to be 81% to reserve pores for Cu melting and infiltration.

[0098] Step 5: Place the sintered billet inside the graphite boat, ensuring that the length, width, and height of the graphite boat can accommodate the billet. The volume of the graphite boat should be 1.5 times the volume of the sintered billet, and its height should be 50mm higher than the billet's height. Place the copper block on top of the billet, ensuring that the melting copper block completely covers the billet. The melting and infiltration process conditions are: vacuum degree 10. -3 Pa, the melting temperature is 1500℃, the holding time is 5h, and the sintering atmosphere is Ar; in step 5, the Cu content in the obtained melting-infiltrated blank is 9wt%.

[0099] Step 6: Perform surface polishing on the obtained melt-infiltrated blank to achieve a surface roughness Ra = 2μm. After the treatment, perform water immersion ultrasonic testing according to the GJB2299A-2005 standard.

[0100] Example 5

[0101] Step 1: Select four powders: tungsten powder with D50: 8μm, rhenium powder with D50: 8μm, lanthanum powder with D50: 400nm, and hafnium powder with D50: 400nm. The ratio of the four powders is Re 9wt%, La 0.6wt%, Hf 1.2wt%, and the remainder is W.

[0102] Step 2: First, the tungsten powder and rhenium powder obtained in Step 1 are loaded into a high-energy ball mill jar in a vacuum glove box to form tungsten-rhenium pre-alloy powder. Then, lanthanum powder and hafnium powder are loaded into the high-energy ball mill jar in a vacuum glove box to form lanthanum-hafnium pre-alloy powder. Finally, the tungsten-rhenium pre-alloy powder and lanthanum-hafnium pre-alloy powder are loaded into the high-energy ball mill jar in a vacuum glove box to form tungsten-rhenium-lanthanum-hafnium pre-alloy powder. During the three ball milling processes, the vacuum glove box is protected with Ar throughout, and the high-energy ball mill jar is filled with Ar for protection. The ball-to-material ratio is 15:1, the rotation speed is 300 rpm, the ball milling time is 3 hours, and the ball milling time is 3 hours after the ball milling is completed. The ball milling balls are tungsten carbide balls. The purity of the Ar used is 99.999%.

[0103] Step 3: Load tungsten, rhenium, lanthanum, and hafnium powder into a molding sleeve, and use a cold isostatic press to hold the pressure at 150 MPa for 100 min to obtain a cold isostatic pressed tungsten, rhenium, lanthanum, and hafnium green billet.

[0104] Step 4: The tungsten-rhenium-lanthanum-hafnium green billet is processed in a vacuum / atmosphere sintering furnace in four stages, specifically:

[0105] The first stage is sintering in an argon atmosphere. The specific process conditions are: sintering atmosphere is Ar, vacuum degree is 10. -1 Pa, heating rate is 5℃ / min, heating to the nitriding temperature, where the nitriding temperature is 900℃;

[0106] The second stage is argon + ammonia nitriding sintering. The specific process is as follows: when the furnace temperature reaches the nitriding temperature of 900℃, the holding time begins and is 1h to 3h. NH3 is introduced simultaneously with the holding time at a flow rate of 3L / min·m³. 2 The gas flow rate is adjusted until the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar = 1:3. During the NH3 introduction process, the NH3 concentration is monitored online every 20 minutes using a laser gas analyzer. If the deviation is >5 vol%, the gas flow rate is adjusted to ensure that the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar = 1:3. After nitriding sintering is completed, Ar is continuously introduced into the furnace and NH3 is discharged. At the same time, the NH3 content is detected online using a laser gas analyzer until the NH3 content is <1 ppm for 30 consecutive minutes. Then, the temperature is raised to the carburizing temperature, which is 1100℃.

[0107] The third stage is argon + acetylene carburizing sintering. The specific process is as follows: when the furnace temperature reaches the carburizing temperature of 1100℃, the holding time begins and lasts for 2 seconds. Simultaneously, C2H2 is introduced at a flow rate of 5 L / min·m³. 2The process continues until the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar = 1:3. During the C2H2 introduction process, the C2H2 concentration is monitored online every 20 minutes using a laser gas analyzer. If the deviation is >3 vol%, the gas flow rate is automatically adjusted to ensure that the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar = 1:3. After carburizing and sintering, Ar is continuously introduced into the furnace while C2H2 is discharged. At the same time, the C2H2 content is detected online using a laser gas analyzer until the C2H2 content is <1 ppm for 30 consecutive minutes. Then, the Ar introduction is stopped and H2 is introduced. The Ar content is detected online using a laser gas analyzer until the Ar content is <1 ppm for 30 consecutive minutes. Then, the temperature is raised to the skeleton sintering temperature, which is 2000℃.

[0108] The fourth stage is skeleton sintering. The specific process conditions are as follows: the skeleton sintering temperature is 2000℃, the sintering atmosphere is H2, and the heat preservation begins when the furnace temperature reaches the skeleton sintering temperature. The heat preservation time is 5h, and the skeleton is cooled with the furnace after the heat preservation is completed. In the fourth stage, the relative density of the skeleton is controlled to be 84% to reserve pores for Cu melting and infiltration.

[0109] Step 5: Place the sintered billet inside the graphite boat, ensuring that the length, width, and height of the graphite boat can accommodate the billet. The volume of the graphite boat should be 1.5 times the volume of the sintered billet, and its height should be 50mm higher than the billet's height. Place the copper block on top of the billet, ensuring that the melting copper block completely covers the billet. The melting and infiltration process conditions are: vacuum degree 10. -3 Pa, the melting temperature is 1500℃, the holding time is 5h, and the sintering atmosphere is Ar; in step 5, the Cu content in the obtained melting-infiltrated blank is 7wt%.

[0110] Step 6: Perform surface polishing on the obtained melt-infiltrated blank to achieve a surface roughness Ra = 2μm. After the treatment, perform water immersion ultrasonic testing according to the GJB2299A-2005 standard.

[0111] Example 6

[0112] Step 1: Select four powders: tungsten powder D50: 7μm, rhenium powder D50: 7μm, lanthanum powder D50: 200nm, and hafnium powder D50: 200nm. The ratio of the four powders is Re 6wt%, La 0.6wt%, Hf 1wt%, and the remainder is W.

[0113] Step 2: First, the tungsten powder and rhenium powder obtained in Step 1 are loaded into a high-energy ball mill jar in a vacuum glove box to form tungsten-rhenium pre-alloy powder. Then, lanthanum powder and hafnium powder are loaded into the high-energy ball mill jar in a vacuum glove box to form lanthanum-hafnium pre-alloy powder. Finally, the tungsten-rhenium pre-alloy powder and lanthanum-hafnium pre-alloy powder are loaded into the high-energy ball mill jar in a vacuum glove box to form tungsten-rhenium-lanthanum-hafnium pre-alloy powder. During the three ball milling processes, the vacuum glove box is protected with Ar throughout, and the high-energy ball mill jar is filled with Ar for protection. The ball-to-material ratio is 15:1, the rotation speed is 300 rpm, the ball milling time is 3 hours, and the ball milling time is 3 hours after the ball milling is completed. The ball milling balls are tungsten carbide balls. The purity of the Ar used is 99.999%.

[0114] Step 3: Load tungsten, rhenium, lanthanum, and hafnium powder into a molding sleeve, and use a cold isostatic press to hold the pressure at 150 MPa for 100 min to obtain a cold isostatic pressed tungsten, rhenium, lanthanum, and hafnium green billet.

[0115] Step 4: The tungsten-rhenium-lanthanum-hafnium green billet is processed in a vacuum / atmosphere sintering furnace in four stages, specifically:

[0116] The first stage is sintering in an argon atmosphere. The specific process conditions are: sintering atmosphere is Ar, vacuum degree is 10. -1 Pa, heating rate is 5℃ / min, heating to the nitriding temperature, where the nitriding temperature is 900℃;

[0117] The second stage is argon + ammonia nitriding sintering. The specific process is as follows: when the furnace temperature reaches the nitriding temperature of 900℃, the holding time begins and is 1h to 3h. NH3 is introduced simultaneously with the holding time at a flow rate of 3L / min·m³. 2 The gas flow rate is adjusted until the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar = 1:3. During the NH3 introduction process, the NH3 concentration is monitored online every 20 minutes using a laser gas analyzer. If the deviation is >5 vol%, the gas flow rate is adjusted to ensure that the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar = 1:3. After nitriding sintering is completed, Ar is continuously introduced into the furnace and NH3 is discharged. At the same time, the NH3 content is detected online using a laser gas analyzer until the NH3 content is <1 ppm for 30 consecutive minutes. Then, the temperature is raised to the carburizing temperature, which is 1100℃.

[0118] The third stage is argon + acetylene carburizing sintering. The specific process is as follows: when the furnace temperature reaches the carburizing temperature of 1100℃, the holding time begins and lasts for 2 seconds. Simultaneously, C2H2 is introduced at a flow rate of 5 L / min·m³. 2The process continues until the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar = 1:3. During the C2H2 introduction process, the C2H2 concentration is monitored online every 20 minutes using a laser gas analyzer. If the deviation is >3 vol%, the gas flow rate is automatically adjusted to ensure that the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar = 1:3. After carburizing and sintering, Ar is continuously introduced into the furnace while C2H2 is discharged. At the same time, the C2H2 content is detected online using a laser gas analyzer until the C2H2 content is <1 ppm for 30 consecutive minutes. Then, the Ar introduction is stopped and H2 is introduced. The Ar content is detected online using a laser gas analyzer until the Ar content is <1 ppm for 30 consecutive minutes. Then, the temperature is raised to the skeleton sintering temperature, which is 1950℃.

[0119] The fourth stage is skeleton sintering. The specific process conditions are as follows: the skeleton sintering temperature is 1950℃, the sintering atmosphere is H2, and the heat preservation begins when the furnace temperature reaches the skeleton sintering temperature. The heat preservation time is 5h, and the skeleton is cooled with the furnace after the heat preservation is completed. In the fourth stage, the relative density of the skeleton is controlled to be 86% to reserve pores for Cu melting and infiltration.

[0120] Step 5: Place the sintered billet inside the graphite boat, ensuring that the length, width, and height of the graphite boat can accommodate the billet. The volume of the graphite boat should be 1.5 times the volume of the sintered billet, and its height should be 50mm higher than the billet's height. Place the copper block on top of the billet, ensuring that the melting copper block completely covers the billet. The melting and infiltration process conditions are: vacuum degree 10. -3 Pa, the melting temperature is 1500℃, the holding time is 5h, and the sintering atmosphere is Ar; in step 5, the Cu content in the obtained melting-infiltrated blank is 5wt%.

[0121] Step 6: Perform surface polishing on the obtained melt-infiltrated blank to achieve a surface roughness Ra = 2μm. After the treatment, perform water immersion ultrasonic testing according to the GJB2299A-2005 standard.

Claims

1. A method for preparing tungsten-rhenium-lanthanum-hafnium copper-infiltrated materials, characterized in that, Includes the following steps: Step 1: Select four types of powders: tungsten powder, rhenium powder, lanthanum powder, and hafnium powder; Step 2: High-energy ball milling is performed on four powders: tungsten powder, rhenium powder, lanthanum powder, and hafnium powder. Step 3: The tungsten-rhenium-lanthanum-hafnium pre-alloy powder obtained in Step 2 is loaded into a molding die and pressed into shape using a cold isostatic press to obtain a tungsten-rhenium-lanthanum-hafnium green billet. Step 4: Place the tungsten-rhenium-lanthanum-hafnium green billet in a vacuum atmosphere sintering furnace for sintering treatment; Step 5: The sintered billet obtained in Step 4 is subjected to copper infiltration treatment in a melting furnace to obtain a copper-infiltrated tungsten-rhenium-lanthanum-hafnium material billet. Step 6: The tungsten-rhenium-lanthanum-hafnium copper-infiltrated material blank obtained in Step 5 is machined and inspected to obtain the tungsten-rhenium-lanthanum-hafnium copper-infiltrated material.

2. The method for preparing the tungsten-rhenium-lanthanum-hafnium copper-infiltrated material according to claim 1, characterized in that, In step 1: the laser particle size range D50 of tungsten powder and rhenium powder is 3μm to 10μm, and the laser particle size range D50 of lanthanum powder and hafnium powder is 50nm to 500nm; In step 1, the ratio of the four raw material powders is as follows: rhenium powder 5wt% to 10wt%, lanthanum powder 0.3wt% to 0.8wt%, hafnium powder 0.1wt% to 0.5wt%, and the balance is tungsten powder.

3. The method for preparing the tungsten-rhenium-lanthanum-hafnium copper-infiltrated material according to claim 1, characterized in that, Step 2 specifically involves: first, loading the tungsten powder and rhenium powder obtained in Step 1 into a high-energy ball mill jar in a vacuum glove box to form tungsten-rhenium pre-alloy powder; then, loading the lanthanum powder and hafnium powder into the high-energy ball mill jar in a vacuum glove box to form lanthanum-hafnium pre-alloy powder; finally, loading the tungsten-rhenium pre-alloy powder and lanthanum-hafnium pre-alloy powder into the high-energy ball mill jar in a vacuum glove box to form tungsten-rhenium-lanthanum-hafnium pre-alloy powder. During all three ball milling processes, the vacuum glove box is under Ar protection throughout, and the high-energy ball mill jar is also under Ar protection. The ball-to-material ratio is 10:1 to 20:1, the rotation speed is 100 rpm to 500 rpm, the milling time is 1 hour to 5 hours, and the milling is followed by a resting period of 1 hour to 5 hours. The milling balls are tungsten carbide balls. The Ar purity used is 99.999%.

4. The method for preparing the tungsten-rhenium-lanthanum-hafnium copper-infiltrated material according to claim 1, characterized in that, Step 3 specifically involves: loading tungsten, rhenium, lanthanum, and hafnium powder into a molding sleeve, and using a cold isostatic press to hold the pressure at 100MPa to 200MPa for 30 to 120 minutes to obtain a cold isostatic pressed tungsten, rhenium, lanthanum, and hafnium green billet.

5. The method for preparing tungsten-rhenium-lanthanum-hafnium copper-infiltrated material according to claim 1, characterized in that, In step 4, the tungsten-rhenium-lanthanum-hafnium green billet is processed in four stages in a vacuum / atmosphere sintering furnace, specifically as follows: The first stage is sintering in an argon atmosphere. The specific process conditions are: sintering atmosphere is Ar, vacuum degree is 10. -1 Pa~10 - 3 Pa, the heating rate is 3℃ / min~8℃ / min, and the temperature is increased to the nitriding temperature, where the nitriding temperature is 800℃~1000℃; The second stage is argon + ammonia nitriding sintering. The specific process is as follows: when the furnace temperature reaches the nitriding temperature of 800℃~1000℃, the holding time begins and is 1h~3h. NH3 is introduced simultaneously at a flow rate of 2L / min·m³. 2 ~5L / min·m 2 The gas flow rate is increased until the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar = 1:1~5. During the NH3 introduction process, the NH3 concentration is monitored online every 10 min to 30 min using a laser gas analyzer. If the deviation is >2 vol% to 8 vol%, the gas flow rate is adjusted to ensure that the volume ratio of the mixed gas in the sintering atmosphere is NH3:Ar = 1:1~5. After nitriding sintering is completed, Ar is continuously introduced into the furnace and NH3 is discharged. At the same time, the NH3 content is detected online using a laser gas analyzer until the NH3 content is <1 ppm for 30 consecutive minutes. Then, the temperature is raised to the carburizing temperature, which is 1000℃ to 1200℃. The third stage is argon + acetylene carburizing and sintering. The specific process is as follows: when the furnace temperature reaches the carburizing temperature of 1000℃~1200℃, the holding time begins and is 1h~3h. During the holding time, C2H2 is introduced at a gas flow rate of 3L / min·m 2 ~7L / min·m 2 The process continues until the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar = 1:1~5. During the C2H2 introduction process, the C2H2 concentration is monitored online every 10 min to 30 min using a laser gas analyzer. If the deviation is >1 vol% to 5 vol%, the gas flow rate is automatically adjusted to ensure that the volume ratio of the mixed gas in the sintering atmosphere is C2H2:Ar = 1:1~5. After carburizing and sintering, Ar is continuously introduced into the furnace while C2H2 is discharged. At the same time, the C2H2 content is detected online using a laser gas analyzer. After the C2H2 content is <1 ppm for 30 consecutive minutes, the Ar introduction is stopped and H2 is introduced. The Ar content is detected online using a laser gas analyzer. After the Ar content is <1 ppm for 30 consecutive minutes, the temperature is raised to the skeleton sintering temperature, which is 1800℃ to 2000℃. The fourth stage is skeleton sintering. The specific process conditions are as follows: the skeleton sintering temperature is 1800℃~2000℃, the sintering atmosphere is H2, and when the furnace temperature reaches the skeleton sintering temperature, the heat preservation begins and the heat preservation time is 2h~6h. After the heat preservation is completed, the skeleton is cooled with the furnace. In the fourth stage, the relative density of the skeleton is controlled to be 72%~87% to reserve pores for Cu melting and infiltration.

6. The method for preparing the tungsten-rhenium-lanthanum-hafnium copper-infiltrated material according to claim 1, characterized in that, Step 5 specifically involves placing the sintered billet inside a graphite boat and placing a copper block on top of the billet, ensuring that the melting copper block completely buries the sintered billet. The melting and infiltration process conditions are: vacuum degree 10. -1 Pa~10 -3 Pa, the melting and infiltration temperature is 1000℃~1600℃, the holding time is 2h~6h, and the sintering atmosphere is Ar; in step 5, the Cu content in the obtained melting and infiltration blank is 5wt%~13wt%.

7. The method for preparing the tungsten-rhenium-lanthanum-hafnium copper-infiltrated material according to claim 1, characterized in that, Step 6 specifically involves: performing surface light treatment on the obtained melt-infiltrated blank to achieve a surface roughness Ra of 0.2 μm to 3.2 μm, followed by water immersion ultrasonic testing, and performing the testing according to the GJB2299A-2005 standard.

8. A tungsten-rhenium-lanthanum-hafnium copper-doped material, characterized in that, It is prepared by the method described in any one of claims 1-7.

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