Lightweight tungsten infiltrated copper material and preparation method thereof

Abstract

Tungsten powder, molybdenum powder, titanium carbide powder and tungsten-copper composite powder are mixed to obtain mixed powder, the mixed powder is pressed and formed to obtain a formed blank, the formed blank is sintered to obtain a ceramic reinforced tungsten framework, the ceramic reinforced tungsten framework is subjected to copper infiltration treatment, and the tungsten-infiltrated copper material is obtained. Titanium carbide and molybdenum are introduced when the tungsten framework is sintered, the strength of the tungsten framework is effectively improved through the solid solution strengthening effect of molybdenum and the second phase strengthening effect of titanium carbide, then the high-temperature strength of the tungsten infiltrated copper material is remarkably improved, meanwhile, the density of the material can be reduced, and weight reduction of tungsten infiltrated copper is achieved. Besides, in the process of sintering the ceramic reinforced tungsten framework, superfine tungsten-copper composite powder is introduced, the sintering performance of the tungsten framework can be remarkably improved, the subsequent copper infiltration effect can be optimized, and therefore the tungsten infiltrated copper material is uniform in component structure, the ablation resistance of the light ablation-resistant tungsten infiltrated copper material is excellent, and the density is greatly reduced compared with existing tungsten infiltrated copper.

Description

Technical Field

[0001] The invention relates to a lightweight tungsten copper infiltrated material and a preparation method thereof, belonging to the technical field of tungsten copper infiltrated material preparation. Background Art

[0002] Tungsten-infiltrated copper is a typical high-temperature composite material composed of tungsten and copper. The two materials neither dissolve in each other nor form an intermetallic compound. Its preparation process involves first pressing tungsten powder into a shape, then sintering it at high temperature to create a tungsten skeleton with a certain porosity. Molten copper is then infiltrated into the tungsten skeleton to create the final tungsten-infiltrated copper material.

[0003] Tungsten-copper infiltrated materials possess excellent thermal and electrical conductivity, arc erosion resistance, high-temperature performance, plasticity, and processability, and are often used as high-temperature evaporation materials and electrical contact materials. In particular, the evaporation cooling effect of copper volatilization at high temperatures effectively reduces the surface temperature of tungsten-copper, enabling it to operate stably under extreme high-temperature conditions. Furthermore, due to its excellent ablation resistance, it is widely used in high-temperature components such as solid rocket engine throat liners.

[0004] However, the research and application of traditional tungsten copper infiltration materials still face the following core challenges:

[0005] First, composition segregation and structural heterogeneity. When using the traditional infiltration method to prepare tungsten-infiltrated copper, the sintering activity is different due to the difference in powder particle size during the preparation of the tungsten skeleton, which easily forms a large number of closed voids. In the subsequent copper infiltration process, this defect will cause composition segregation and structural heterogeneity of the tungsten and copper phases. Usually, a small amount of copper powder is added as an inducer by mixing element powders to improve the infiltration effect, but it is difficult to achieve structural homogeneity at the microscopic level by mixing elements. Therefore, optimizing the addition method of the inducer is a key breakthrough to improve the structural uniformity of tungsten-infiltrated copper.

[0006] The second is the bottleneck of anti-ablation performance. The traditional tungsten-copper-infiltrated anti-ablation material has a two-stage ablation process: first, the sweating cooling effect of copper reduces the surface temperature; second, when the copper is exhausted due to sweating, the tungsten skeleton ablates in an ultra-high temperature environment. Due to the low strength, insufficient ablation resistance and poor dimensional stability of the tungsten skeleton in an ultra-high temperature ablation environment, it can no longer meet the higher requirements of the aerospace field for lightweight anti-ablation materials. Therefore, how to improve the ablation resistance of tungsten-copper-infiltrated materials under extreme conditions has become one of the key research directions in this field.

[0007] Third, the density is too high. Lightweighting and weight reduction are the eternal pursuit in the aerospace field. The density of traditional high-temperature tungsten copper infiltrated materials is 17~18g / cm 3 , it is urgent to reduce the density to meet the requirements of lightweighting and weight reduction in aerospace. Summary of the Invention

[0008] In view of the shortcomings of the prior art, the first object of the present invention is to provide a method for preparing a lightweight tungsten-copper-infiltrated material. The preparation method of the present invention is simple and controllable and suitable for industrial production.

[0009] The second object of the present invention is to provide a lightweight tungsten copper infiltrated material prepared by the above-mentioned preparation method. The tungsten copper infiltrated material prepared by the preparation method of the present invention has uniform composition and structure, excellent ablation resistance, and its density is greatly reduced compared with the existing tungsten copper infiltrated material.

[0010] In order to achieve the above object, the present invention adopts the following technical solutions:

[0011] The present invention discloses a method for preparing a lightweight tungsten-copper-infiltrated material, comprising mixing tungsten powder, molybdenum powder, titanium carbide powder, and tungsten-copper composite powder to obtain a mixed powder, pressing the mixed powder to obtain a formed blank, sintering the formed blank to obtain a ceramic-reinforced tungsten skeleton, and subjecting the ceramic-reinforced tungsten skeleton to a copper-infiltrated treatment to obtain the tungsten-copper-infiltrated material.

[0012] The particle size of the tungsten-copper composite powder is ≤2 μm;

[0013] In the mixed powder, the mass fraction of molybdenum powder is 10-30%.

[0014] The preparation method of the present invention adds ultrafine tungsten-copper composite powder, titanium carbide powder, and molybdenum powder to the raw materials. Through the synergy of tungsten-copper composite powder, titanium carbide powder, molybdenum powder and tungsten powder, the performance of the lightweight tungsten-infiltrated copper material is improved:

[0015] First, the addition of titanium carbide constructs a ceramic reinforcement phase in the tungsten skeleton. During the high-temperature sintering process, titanium carbide reacts with tungsten and molybdenum at high temperatures to form a strong interface bond, forming an ultra-high-temperature ceramic-reinforced tungsten skeleton. This not only significantly improves the high-temperature strength of the tungsten skeleton, but also improves the low-density characteristics of the ceramic phase (TiC, 4.93 g / cm 3 , tungsten, 19.35 g / cm 3 ) reduces the overall density of the material, and at the same time utilizes the high melting point (3140℃) and ablation resistance of TiC to give the tungsten copper infiltrated material excellent ablation resistance in extreme environments such as ultra-high temperature and high-speed airflow erosion.

[0016] Secondly, the tungsten-copper composite powder plays a dual role: on the one hand, during the sintering process of the tungsten skeleton, the ultrafine tungsten-copper composite powder promotes the diffusion and densification of tungsten particles through the liquid phase sintering mechanism, thereby improving the density of the tungsten skeleton; on the other hand, during the copper infiltration process, the copper phase in the tungsten-copper composite powder acts as an infiltration inducer, which optimizes the wettability and fluidity of the copper liquid in the tungsten skeleton, thereby achieving significant optimization of the uniformity of the material composition and organization after infiltration.

[0017] Furthermore, the present invention adds molybdenum powder in an appropriate proportion, and since the density of molybdenum is 10.2 g / cm3 , which is much smaller than the density of tungsten (19.35 g / cm 3 Therefore, the density of tungsten copper infiltrated materials can be greatly reduced. In addition, molybdenum can produce solid solution strengthening in the tungsten matrix and cooperate with titanium carbide to further improve the strength of the tungsten skeleton, thereby improving the high-temperature strength of tungsten copper infiltrated materials.

[0018] With the cooperation of the above components, the tungsten copper infiltrated material prepared by the present invention has uniform composition and structure, excellent ablation resistance, and is lightweight, and is particularly suitable for high-temperature components such as throat liners and nozzles in the aerospace field.

[0019] However, in the present invention, the amount of molybdenum cannot be too much, otherwise the ablation resistance of the composite material will be reduced.

[0020] In a preferred embodiment, the preparation process of the tungsten-copper composite powder is as follows: ammonium metatungstate and copper nitrate are dissolved in pure water to form a precursor solution, the precursor solution is centrifugally spray-dried to obtain a precursor powder, the precursor powder is calcined at 580-620°C for 1-3h to obtain a tungsten-copper composite oxide powder, and then reduced at 750-820°C in a hydrogen atmosphere to obtain a tungsten-copper composite powder.

[0021] The ultrafine tungsten-copper composite powder prepared using this method achieves uniform microscopic bonding of tungsten and copper. The introduction of induced copper into the tungsten-copper composite powder significantly improves the uniformity of the powder mixing process due to its similar overall density to tungsten powder, thereby ensuring a uniform compositional distribution and microstructure of the induced copper within the tungsten framework. Furthermore, the ultrafine tungsten-copper composite powder exhibits excellent sintering activity, reducing tungsten grain coarsening during high-temperature sintering, ultimately imparting superior overall performance to the tungsten-copper infiltrated material.

[0022] In a preferred embodiment, the copper content of the mixed powder is 1-5%, preferably 1-3%. Experiments have found that controlling the copper content of the ceramic-reinforced tungsten framework within this range results in optimal performance. Lower copper content results in a less pronounced effect of copper induction, while higher copper content can affect sintering of the tungsten framework due to the significant difference in melting points between copper and tungsten.

[0023] In the present invention, the mass ratio of tungsten to copper in the tungsten-copper composite powder does not need to be specially controlled. What is important is to control the mass fraction of copper in the mixed powder, i.e., the ceramic reinforced tungsten skeleton. The mass fraction of copper in the ceramic reinforced tungsten skeleton can be regulated by the proportion of tungsten-copper composite powder in the mixed powder and the composition ratio of tungsten to copper in the tungsten-copper composite powder (such as W-10Cu, W-20Cu, W-50Cu, etc.).

[0024] In a preferred embodiment, the particle size of the tungsten-copper composite powder is 0.5-2 μm. By controlling the particle size of the tungsten-copper composite powder within this range, the performance of the resulting material is better.

[0025] In a preferred embodiment, the particle size of the tungsten powder is 2-10 μm, the particle size of the molybdenum powder is 2-10 μm, the particle size of the molybdenum powder is ≤ that of the tungsten powder, and the particle size of the titanium carbide powder is 30 nm-5 μm.

[0026] The particle size of the raw materials is controlled within the above range, and the particle size of the molybdenum powder is controlled to be ≤ the particle size of the tungsten powder. Preferably, the particle size of the molybdenum powder is smaller than the particle size of the tungsten powder. The resulting lightweight tungsten copper infiltrated material has the highest skeleton density and the best performance.

[0027] In a preferred embodiment, the mixed powder comprises the following components, by mass percentage: 10-30% molybdenum powder, 0.5-5% titanium carbide powder, 1-10% tungsten-copper composite powder, and the balance tungsten powder.

[0028] The performance is optimized by controlling the components in the mixed powder within the above range. If the amount of titanium carbide powder added is too small, the reinforcement effect is limited. If too much titanium carbide powder is added, the material strength will also decrease because the TiC content is too high and segregation occurs inside the material. TiC is a high melting point, strong covalent bond compound that is difficult to sinter and densify. When the alloy is under load, the TiC aggregation area is prone to brittle fracture, thereby deteriorating the mechanical properties of the alloy. Although the addition of tungsten-copper composite powder can significantly improve the uniformity of the powder mixing process and improve the sintering performance, the addition of molybdenum powder can form solid solution strengthening. However, excessive amounts will reduce the mechanical properties and ablation properties of the material.

[0029] Further preferably, the mixed powder comprises the following components, by mass percentage, 10-20% molybdenum powder, 1-2% titanium carbide powder, 5-10% tungsten-copper composite powder, and the balance tungsten powder.

[0030] Preferably, the pressing method is cold isostatic pressing, the molding pressure is 50-200 MPa, and the holding time is 1-5 minutes.

[0031] Preferably, the sintering is performed in a non-oxidizing atmosphere.

[0032] Further preferably, the non-oxidizing atmosphere is selected from at least one of hydrogen, vacuum, and argon.

[0033] In a preferred embodiment, the sintering temperature is 1600-2200°C, preferably 1800-2000°C, and the sintering time is 1-4 hours. Experiments have found that even at lower temperatures, a ceramic reinforced tungsten skeleton with a relatively high density can be obtained under the formulation of the present invention.

[0034] In a preferred embodiment, the density of the ceramic reinforced tungsten skeleton is 70-90%, preferably 75-86%, and more preferably 82-86%.

[0035] Experiments have found that when the density of the ceramic-reinforced tungsten skeleton is controlled within the above range, the performance of the resulting tungsten-copper-infiltrated material is optimal.

[0036] In a preferred embodiment, the temperature of the copper infiltration treatment is 1100-1400° C., and the time of the copper infiltration treatment is 1-4 hours.

[0037] Since the present invention adds ultrafine tungsten-copper composite powder, the infiltration efficiency and uniformity are significantly improved. On the one hand, the copper infiltration time can be shortened, and on the other hand, the present invention can make the copper infiltration effect of thick and large-sized components more uniform.

[0038] The present invention also provides a tungsten-copper-infiltrated material prepared by the above preparation method.

[0039] Principles and advantages

[0040] 1. Ultra-high temperature ceramic titanium carbide and molybdenum reinforced tungsten skeleton

[0041] In the preparation process of tungsten skeleton, ultra-high temperature ceramics titanium carbide and molybdenum are innovatively introduced. On the one hand, the density of titanium carbide is only 4.9g / cm 3 , the density of molybdenum is 10.2 g / cm 3 , which is lower than tungsten's 19.3g / cm 3 By introducing titanium carbide and molybdenum, the solid solution strengthening of molybdenum and the second-phase strengthening of titanium carbide form a ceramic-reinforced tungsten skeleton, which not only increases the skeleton strength but also effectively reduces the overall material density. On the other hand, in ultra-high temperature oxidative ablation environments, after the copper in traditional tungsten-copper-infiltrated materials is exhausted through sweating and cooling, the tungsten skeleton is easily oxidized to volatile WO3, resulting in a decrease in ablation resistance. TiC has a high melting point of 3140°C, and its oxidation product, TiO2, not only has a higher melting point but also exhibits superior oxidation and ablation resistance to WO3. Therefore, the introduction of TiC can significantly enhance the ablation resistance of tungsten-copper-infiltrated materials under extreme conditions such as ultra-high temperatures and high-speed airflow.

[0042] 2. Ultrafine tungsten-copper composite powder induction system

[0043] During the preparation of the tungsten skeleton, a specific amount of ultrafine tungsten-copper composite powder is innovatively added. This powder has multiple mechanisms of action: first, the high specific surface area of ​​the ultrafine powder can significantly promote the sintering and densification process of the tungsten skeleton, thereby improving the overall strength of the skeleton; second, the copper element pre-introduced into the powder acts as an "inducer" in the subsequent infiltration process, effectively improving the infiltration and diffusion of molten copper, ultimately significantly improving the infiltration efficiency and uniformity; third, due to the density difference between tungsten and copper, directly adding copper powder as an inducer when sintering the tungsten skeleton still makes it difficult to ensure compositional uniformity. The present invention adds ultrafine tungsten-copper composite powder. The tungsten-copper powder has a similar density to tungsten powder, which can improve the distribution uniformity of copper during the mixing and sintering process of the tungsten skeleton, thereby ensuring the consistency of the composition and organizational structure of the tungsten-copper infiltrated material.

[0044] The preparation method of the present invention is simple and controllable. The density of the prepared lightweight tungsten-infiltrated copper material is significantly lower than that of the tungsten-infiltrated copper in the prior art, and the composition and structure are uniform. It can greatly enhance the ablation resistance of the tungsten-infiltrated copper material in ultra-high temperature and high-speed airflow scouring environments, making it particularly suitable for high-temperature components in the aerospace field. DETAILED DESCRIPTION

[0045] Example 1

[0046] Step 1: Preparation of tungsten-copper composite powder

[0047] Based on the W-20Cu (wt.%) composition, ammonium metatungstate and copper nitrate were dissolved in pure water in appropriate proportions to prepare a precursor solution. The precursor powder was then prepared by high-speed centrifugal spray drying. This was then calcined at 580°C for 3 hours to obtain a tungsten-copper composite oxide powder. This was then reduced at 750°C in a hydrogen atmosphere to produce an ultrafine tungsten-copper composite powder with a copper content of 20% and a particle size of approximately 0.8μm.

[0048] Step 2: Ceramic reinforced skeleton pressing

[0049] Weigh 0.5g of titanium carbide powder (50nm particle size), 5g of tungsten-copper composite powder (~0.8μm), 10g of molybdenum powder (2μm particle size), and 84.5g of tungsten powder (2μm particle size) and mix them evenly. Use cold isostatic pressing at a pressure of 50MPa for 5 minutes to form an I-shaped tensile test blank.

[0050] Step 3: Sintering of ceramic reinforced tungsten skeleton

[0051] The obtained formed blank was sintered at 1600°C in a hydrogen atmosphere for 4 hours to obtain a ceramic reinforced tungsten skeleton with a density of 79.8%.

[0052] Step 4: Ceramic reinforced tungsten skeleton infiltrated with copper

[0053] The ceramic reinforced tungsten skeleton was subjected to high temperature copper infiltration treatment at 1100℃ for 4h to obtain a new type of tungsten infiltrated copper.

[0054] Comparative Example 1

[0055] Step 1: Ceramic reinforced skeleton pressing

[0056] Weigh 0.5g of titanium carbide powder (50nm particle size), 10g of molybdenum powder (2μm particle size), and 89.5g of tungsten powder (2μm particle size) and mix them evenly. Use cold isostatic pressing at a pressure of 50MPa and a holding time of 5min to form an I-shaped tensile test blank.

[0057] Step 3: Sintering of ceramic reinforced tungsten skeleton

[0058] The obtained formed blank was sintered at 1600°C in a hydrogen atmosphere for 4 hours to obtain a ceramic reinforced tungsten skeleton with a density of 75.5%.

[0059] Step 4: Ceramic reinforced tungsten skeleton infiltrated with copper

[0060] The ceramic reinforced tungsten skeleton was subjected to high temperature copper infiltration treatment at 1100°C for 4 hours to obtain tungsten infiltrated copper.

[0061] Comparative Example 2

[0062] Step 1: Same as step 1 in Example 1.

[0063] Step 2: Ceramic reinforced skeleton pressing

[0064] Weigh 5g of tungsten-copper composite powder (~0.8μm), 10g of molybdenum powder (particle size 2μm), and 85g of tungsten powder (particle size 2μm) and mix them evenly. Use cold isostatic pressing at a pressure of 50MPa and a holding time of 5min to obtain a blank.

[0065] Step 3: Sintering of ceramic reinforced tungsten skeleton

[0066] The obtained formed blank was sintered at 1600°C in a hydrogen atmosphere for 4 hours to obtain a ceramic reinforced tungsten skeleton with a density of 80.5%.

[0067] Step 4: Ceramic reinforced tungsten skeleton infiltrated with copper

[0068] The ceramic reinforced tungsten skeleton was subjected to high temperature copper infiltration treatment at 1100℃ for 4h to obtain a new type of tungsten infiltrated copper.

[0069] Comparative Example 3

[0070] Step 1: Same as step 1 in Example 1.

[0071] Step 2: Ceramic reinforced skeleton pressing

[0072] Weigh 0.5g of titanium carbide powder (50nm particle size), 5g of tungsten-copper composite powder (~0.8μm), 40g of molybdenum powder (2μm particle size), and 54.5g of tungsten powder and mix them evenly. Use cold isostatic pressing at a pressure of 50MPa and a dwell time of 5min to obtain a blank.

[0073] Step 3: Sintering of ceramic reinforced tungsten skeleton

[0074] The obtained formed blank was sintered at 1600°C in a hydrogen atmosphere for 4 hours to obtain a ceramic reinforced tungsten skeleton with a density of 81.6%.

[0075] Step 4: Ceramic reinforced tungsten skeleton infiltrated with copper

[0076] The ceramic reinforced tungsten skeleton was subjected to high temperature copper infiltration treatment at 1100℃ for 4h to obtain a new type of tungsten infiltrated copper.

[0077] Example 2

[0078] Step 1: Preparation of tungsten-copper composite powder

[0079] Based on the W-30Cu (wt.%) composition, ammonium metatungstate and copper nitrate were dissolved in pure water in appropriate proportions to prepare a precursor solution. This precursor powder was then prepared by high-speed centrifugal spray drying. This was then calcined at 600°C for 2 hours to obtain a tungsten-copper composite oxide powder. This was then reduced at 780°C in a hydrogen atmosphere to produce an ultrafine tungsten-copper composite powder with a copper content of 30% and a particle size of approximately 1 μm.

[0080] Step 2: Ceramic reinforced skeleton pressing

[0081] Weigh 1 g of titanium carbide powder (100 nm particle size), 10 g of tungsten-copper composite powder (~1 μm), 15 g of molybdenum powder (2 μm particle size), and 74 g of tungsten powder (5 μm particle size) and mix them evenly. Cold isostatic pressing is then performed at a pressure of 80 MPa and a dwell time of 4 minutes to obtain a blank.

[0082] Step 3: Sintering of ceramic reinforced tungsten skeleton

[0083] The obtained formed blank was sintered at 1700°C in a hydrogen atmosphere for 3 hours to obtain a ceramic reinforced tungsten skeleton with a density of 81.9%.

[0084] Step 4: Ceramic reinforced tungsten skeleton infiltrated with copper

[0085] The ceramic reinforced tungsten skeleton was subjected to high temperature copper infiltration treatment at 1150℃ for 3h to obtain a new type of tungsten infiltrated copper.

[0086] Example 3

[0087] Step 1: Preparation of tungsten-copper composite powder

[0088] Based on the W-50Cu (wt.%) composition, ammonium metatungstate and copper nitrate were dissolved in pure water in appropriate proportions to prepare a precursor solution. The precursor powder was then prepared by high-speed centrifugal spray drying. This was then calcined at 620°C for 1 hour to obtain a tungsten-copper composite oxide powder. This was then reduced at 820°C in a hydrogen atmosphere to produce an ultrafine tungsten-copper composite powder with a copper content of 50% and a particle size of approximately 2 μm.

[0089] Step 2: Ceramic reinforced skeleton pressing

[0090] Weigh 2g of titanium carbide powder (1μm particle size), 4g of tungsten-copper composite powder (~1μm), 20g of molybdenum powder (4μm particle size), and 74g of tungsten powder (6μm particle size) and mix them evenly. Use cold isostatic pressing at a pressure of 150 MPa and a dwell time of 2 minutes to obtain a blank.

[0091] Step 3: Sintering of ceramic reinforced tungsten skeleton

[0092] The obtained formed blank was sintered at 1800°C in a hydrogen atmosphere for 3 hours to obtain a ceramic reinforced tungsten skeleton with a density of 83.2%.

[0093] Step 4: Ceramic reinforced tungsten skeleton infiltrated with copper

[0094] The ceramic reinforced tungsten skeleton was subjected to high temperature copper infiltration treatment at 1180℃ for 2h to obtain a new type of tungsten infiltrated copper.

[0095] Example 4

[0096] Step 1: Preparation of tungsten-copper composite powder

[0097] Based on the W-30Cu (wt.%) composition, ammonium metatungstate and copper nitrate were dissolved in pure water in appropriate proportions to prepare a precursor solution. This precursor powder was then prepared by high-speed centrifugal spray drying. This was then calcined at 600°C for 1.5 hours to obtain a tungsten-copper composite oxide powder. This was then reduced at 800°C in a hydrogen atmosphere to produce an ultrafine tungsten-copper composite powder with a copper content of 30% and a particle size of approximately 1.5 μm.

[0098] Step 2: Ceramic reinforced skeleton pressing

[0099] Weigh 1.5g of titanium carbide powder (2μm particle size), 5g of tungsten-copper composite powder (~1μm), 10g of molybdenum powder (4μm particle size), and 83.5g of tungsten powder (8μm particle size) and mix them evenly. Use cold isostatic pressing at a pressure of 200MPa and a dwell time of 1min to obtain a blank.

[0100] Step 3: Sintering of ceramic reinforced tungsten skeleton

[0101] The obtained formed blank was sintered at 2000°C in a hydrogen atmosphere for 2 hours to obtain a ceramic reinforced tungsten skeleton with a density of 85.8%.

[0102] Step 4: Ceramic reinforced tungsten skeleton infiltrated with copper

[0103] The ceramic reinforced tungsten skeleton was subjected to high temperature copper infiltration treatment at 1400℃ for 1h to obtain a new type of tungsten infiltrated copper.

[0104] Example 5

[0105] Step 1: Preparation of tungsten-copper composite powder

[0106] Based on the W-30Cu (wt.%) composition, ammonium metatungstate and copper nitrate were dissolved in pure water in appropriate proportions to prepare a precursor solution. This precursor powder was then prepared by high-speed centrifugal spray drying. This was then calcined at 600°C for 1.5 hours to obtain a tungsten-copper composite oxide powder. This was then reduced at 800°C in a hydrogen atmosphere to produce an ultrafine tungsten-copper composite powder with a copper content of 30% and a particle size of approximately 1.5 μm.

[0107] Step 2: Ceramic reinforced skeleton pressing

[0108] Weigh 5g of titanium carbide powder (5μm particle size), 10g of tungsten-copper composite powder (~1μm), 30g of molybdenum powder (3μm particle size), and 55g of tungsten powder (6μm particle size) and mix them evenly. Use cold isostatic pressing at a pressure of 200 MPa and a holding time of 1 minute to obtain a blank.

[0109] Step 3: Sintering of ceramic reinforced tungsten skeleton

[0110] The obtained formed blank was sintered at 2200°C in a hydrogen atmosphere for 1 hour to obtain a ceramic reinforced tungsten skeleton with a density of 89.7%.

[0111] Step 4: Ceramic reinforced tungsten skeleton infiltrated with copper

[0112] The ceramic reinforced tungsten skeleton was subjected to high temperature copper infiltration treatment at 1200℃ for 2h to obtain a new type of tungsten infiltrated copper.

[0113] The tungsten-infiltrated copper prepared in each embodiment and comparative example was subjected to performance tests, and the results are shown in Table 1. The ablation resistance was tested in accordance with GJB323A-96.

[0114]

[0115] From the data in the table we can see that:

[0116] Comparing Example 1 with Comparative Example 1, the addition of ultrafine tungsten-copper composite powder can significantly improve the density of the tungsten skeleton, while enhancing the room temperature and high temperature mechanical properties of the tungsten-copper infiltrated material.

[0117] Comparing Example 1 with Comparative Example 2, after introducing ultra-high temperature ceramic TiC into the tungsten skeleton, the room temperature and high temperature mechanical properties of the tungsten copper infiltrated material are significantly improved compared with the traditional tungsten copper infiltrated system, especially the high temperature mechanical properties and ablation resistance are more prominently improved.

[0118] Comparing Example 1 with Comparative Example 3, when too much molybdenum element is introduced into the tungsten skeleton, the ablation resistance of the tungsten copper infiltrated material decreases.

Claims

1. A method for preparing a lightweight tungsten-copper infiltrated material, characterized by: Tungsten powder, molybdenum powder, titanium carbide powder and tungsten-copper composite powder are mixed to obtain a mixed powder, the mixed powder is pressed into a formed blank, the formed blank is sintered to obtain a ceramic-reinforced tungsten skeleton, and the ceramic-reinforced tungsten skeleton is infiltrated with copper to obtain a tungsten-copper-infiltrated material; The particle size of the tungsten-copper composite powder is ≤2 μm.

2. A method for preparing a lightweight tungsten copper infiltrated material according to claim 1, characterized in that: The preparation process of the tungsten-copper composite powder is as follows: ammonium metatungstate and copper nitrate are dissolved in pure water to prepare a precursor solution, which is then centrifugally spray-dried to obtain a precursor powder, and the precursor powder is calcined at 580-620°C for 1-3 hours to obtain a tungsten-copper composite oxide powder, which is then reduced at 750-820°C in a hydrogen atmosphere to obtain the tungsten-copper composite powder.

3. The method for preparing a lightweight tungsten copper infiltrated material according to claim 1 or 2, characterized in that: In the mixed powder, the mass fraction of copper is 1-5%.

4. The method for preparing a lightweight tungsten copper infiltrated material according to claim 1 or 2, characterized in that: The particle size of the tungsten-copper composite powder is 0.5-2 μm; The particle size of the tungsten powder is 2-10 μm, the particle size of the molybdenum powder is 2-10 μm, the particle size of the molybdenum powder is less than or equal to the particle size of the tungsten powder, and the particle size of the titanium carbide powder is 30 nm-5 μm.

5. The method for preparing a lightweight tungsten copper infiltrated material according to claim 1 or 2, characterized in that: The mixed powder has the following components, calculated by mass percentage, including 10-30% molybdenum powder, 0.5-5% titanium carbide powder, 1-10% tungsten-copper composite powder, and the balance being tungsten powder.

6. The method for preparing a lightweight tungsten copper infiltrated material according to claim 1 or 2, characterized in that: The pressing method is cold isostatic pressing, the molding pressure is 50-200 MPa, and the holding time is 1-5 minutes.

7. The method for preparing a lightweight tungsten copper infiltrated material according to claim 1 or 2, characterized in that: The sintering is carried out in a non-oxidizing atmosphere; The sintering temperature is 1600-2200° C., and the sintering time is 1-4 hours.

8. The method for preparing a lightweight tungsten copper infiltrated material according to claim 1 or 2, characterized in that: The density of the ceramic reinforced tungsten skeleton is 70-90%.

9. The method for preparing a lightweight tungsten copper infiltrated material according to claim 1 or 2, characterized in that: The temperature of the copper infiltration treatment is 1100-1400° C., and the time of the copper infiltration treatment is 1-4 hours.

10. A lightweight tungsten-copper infiltrated material prepared by the preparation method according to any one of claims 1 to 9.

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