Tungsten infiltrated copper material and preparation method thereof

Abstract

Tungsten 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. Superfine tungsten-copper composite powder and titanium carbide powder are added into raw materials; through introduction of TiC, the strength of the tungsten framework can be effectively improved, then the high-temperature strength of the tungsten infiltrated copper material is remarkably improved, meanwhile, the material density can be reduced, in addition, the ablation resistance of the tungsten infiltrated copper material under the extreme conditions of ultra-high temperature, high-speed airflow scouring and the like can be remarkably improved, and the tungsten-copper composite powder can improve the sintering performance of the tungsten framework; and the sintering densification of a tungsten framework is promoted, and the effect of inducing copper is achieved, so that the prepared tungsten infiltrated copper material is uniform in component structure, excellent in ablation resistance and particularly suitable for high-temperature parts in the aerospace field.

Description

Technical Field

[0001] The invention relates to a 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, and a large number of closed voids are easily formed. 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 one of the key breakthroughs to improve the structural uniformity of tungsten-infiltrated copper.

[0006] The second bottleneck is the ablation resistance performance. The traditional tungsten-infiltrated copper as an ablation-resistant 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 abslates in an ultra-high temperature environment. Due to the insufficient ablation resistance, low strength and poor dimensional stability of the tungsten skeleton in an ultra-high temperature and high pressure ablation environment, it can no longer meet the higher requirements of the aerospace field for lightweight ablation-resistant materials. Therefore, how to improve the ablation resistance of tungsten-infiltrated copper materials under extreme conditions has become one of the key research directions in this field. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the first object of the present invention is to provide a method for preparing a tungsten-copper-infiltrated material. The preparation method of the present invention is simple and controllable and suitable for industrial production.

[0008] The second object of the present invention is to provide a 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 can achieve weight reduction.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] The present invention provides a method for preparing a tungsten-copper-infiltrated material, comprising mixing tungsten 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 infiltrating the ceramic-reinforced tungsten skeleton with copper to obtain the tungsten-copper-infiltrated material.

[0011] The particle size of the tungsten-copper composite powder is ≤2 μm.

[0012] The preparation method of the present invention achieves comprehensive optimization of the performance of tungsten-copper infiltrated materials by introducing ultrafine tungsten-copper composite powder and titanium carbide powder into the raw materials:

[0013] First, the addition of titanium carbide constructs a ceramic reinforcement phase in the tungsten skeleton. Through the interface bonding of TiC and tungsten during high-temperature sintering, an ultra-high-temperature ceramic-reinforced tungsten skeleton is formed, which 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 anti-ablation properties of TiC to give the tungsten copper infiltrated material excellent anti-ablation ability in extreme environments such as ultra-high temperature and high-speed airflow erosion.

[0014] 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 sintering 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.

[0015] 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 powder is obtained after centrifugal spray drying, the precursor powder is calcined at 580-620°C for 1-3h to obtain tungsten-copper composite oxide powder, and then the tungsten-copper composite oxide powder is reduced at 750-820°C in a hydrogen atmosphere to obtain tungsten-copper composite powder.

[0016] In the existing traditional process, when induced copper is introduced by directly adding copper powder, there is a significant density difference between tungsten powder and copper powder (the density of tungsten is 19.3g / cm 3, the density of copper is 8.96g / cm 3 ), the powder mixing process is prone to uneven mixing, which ultimately leads to defects in composition segregation and uneven structure in the tungsten-copper-infiltrated material. The ultrafine tungsten-copper composite powder prepared using the above scheme can achieve uniform compounding of tungsten and copper at the microscale. When induced copper is introduced into the tungsten-copper composite powder, its overall density is similar to that of tungsten powder, which can significantly improve the uniformity of the powder mixing process, thereby ensuring the uniform composition distribution and microstructure of the induced copper in the tungsten skeleton. In addition, the ultrafine tungsten-copper composite powder has excellent sintering activity, reducing the coarsening of tungsten grains during high-temperature sintering, ultimately giving the tungsten-copper-infiltrated material better overall performance.

[0017] In a preferred embodiment, the copper content of the mixed powder is 1-6%, preferably 3-6%. 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.

[0018] 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.).

[0019] 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.

[0020] In a preferred embodiment, the particle size of the tungsten powder is 2-10 μm, and the particle size of the titanium carbide powder is 30 nm-5 μm.

[0021] In a preferred embodiment, the mixed powder comprises the following components, calculated by mass percentage: 0.5-5% titanium carbide powder, 2-25% tungsten-copper composite powder, and the balance tungsten powder.

[0022] Further preferably, the mixed powder has the following composition by mass percentage: 1.5-3% titanium carbide powder, 5-15% tungsten-copper composite powder, and the balance tungsten powder.

[0023] 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, excessive addition will also lead to a decrease in performance.

[0024] In a preferred embodiment, the mixed powder is mixed with a forming agent and then pressed to obtain a formed blank. The amount of the additive added is 0.5-2% of the mixed powder, and the forming agent is selected from at least one of paraffin, stearic acid, and polyethylene glycol.

[0025] Experiments have found that ultrafine tungsten-copper composite powder can not only improve sintering performance, but also enhance formability. Therefore, it can be pressed and formed even without adding a forming agent. However, the appropriate addition of a small amount of forming agent can obtain more uniform and controllable pores and ideal porosity, thereby further promoting composition uniformity and improving material performance.

[0026] Preferably, the pressing method is cold isostatic pressing, the molding pressure is 50-200 MPa, and the holding time is 1-5 minutes.

[0027] Preferably, the sintering is performed in a non-oxidizing atmosphere.

[0028] Further preferably, the non-oxidizing atmosphere is selected from at least one of hydrogen, vacuum, and argon.

[0029] In a preferred embodiment, the sintering temperature is 1600-2200° C., preferably 1800-2200° C., and the sintering time is 0.5-5 h, preferably 1-3 h.

[0030] In a preferred embodiment, the density of the ceramic reinforced tungsten skeleton is 70-90%, preferably 75-88%, and more preferably 82-88%.

[0031] 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.

[0032] In a preferred embodiment, the temperature of the copper infiltration treatment is 1100-1400° C., and the time of the copper infiltration treatment is 0.5-4 hours, preferably 1-2 hours.

[0033] 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.

[0034] The present invention also provides a tungsten-copper-infiltrated material prepared by the above preparation method.

[0035] Principles and advantages

[0036] 1: Ultra-high temperature ceramic TiC reinforcement system. In the process of preparing tungsten skeleton, the present invention innovatively introduces ultra-high temperature ceramic TiC. On the one hand, the density of TiC is only 4.9g / cm 3 , significantly lower than tungsten's 19.3g / cm 3 By forming a ceramic-reinforced tungsten skeleton, the strength of the skeleton is increased while effectively reducing the overall material density. On the other hand, in ultra-high temperature oxidative ablation environments, the copper in traditional tungsten-copper-infiltrated materials is easily oxidized to volatile WO3 after being exhausted through sweating and cooling, 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 significantly enhances the ablation resistance of tungsten-copper-infiltrated materials under extreme conditions such as ultra-high temperatures and high-velocity airflow.

[0037] 2. Ultrafine tungsten-copper composite powder induction system: 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 characteristics 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, which can effectively improve the infiltration and diffusion of molten copper, and ultimately significantly improve the infiltration efficiency and uniformity; third, due to the density difference between tungsten and copper, directly adding copper powder as induction copper when sintering the tungsten skeleton is still difficult to ensure the uniformity of the composition. The present invention adds it in the form of ultrafine tungsten-copper composite powder. The density of tungsten-copper powder is similar to that of tungsten powder. It 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.

[0038] The preparation method of the present invention is simple and controllable; the prepared tungsten-copper-infiltrated material has uniform composition and structure, excellent ablation resistance, and can achieve weight reduction. DETAILED DESCRIPTION

[0039] Example 1

[0040] Step 1: Preparation of tungsten-copper composite powder

[0041] Based on the W-10Cu (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 10% and a particle size of approximately 0.5 μm.

[0042] Step 2: Ceramic reinforced skeleton pressing

[0043] Titanium carbide powder (particle size ~50nm), tungsten-copper composite powder (~0.5μm), and tungsten powder (particle size ~2μm) were weighed and mixed uniformly in a mass ratio of 0.5:10:89.5. Cold isostatic pressing was used at a pressure of 60MPa and a dwell time of 4min to produce a Ø40mm diameter blank.

[0044] Step 3: Sintering of ceramic reinforced tungsten skeleton

[0045] 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 76.5%.

[0046] Step 4: Ceramic reinforced tungsten skeleton infiltrated with copper

[0047] The ceramic reinforced tungsten skeleton was subjected to high temperature copper infiltration treatment at 1100℃ for 3h to obtain a new type of tungsten infiltrated copper.

[0048] Comparative Example 1

[0049] Step 1: Ceramic reinforced skeleton pressing

[0050] Weigh 500g of titanium carbide powder (particle size ~50nm) and tungsten powder (particle size ~2μm) in a mass ratio of 0.5:99.5 and mix them evenly. Cold isostatic pressing is used at a pressure of 50MPa and a dwell time of 5min to produce a Ø40mm diameter blank.

[0051] Step 3: Sintering of ceramic reinforced tungsten skeleton

[0052] 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 71.3%.

[0053] Step 4: Ceramic reinforced tungsten skeleton infiltrated with copper

[0054] The ceramic reinforced tungsten skeleton was subjected to high temperature copper infiltration treatment at 1100°C for 3 hours to obtain tungsten infiltrated copper.

[0055] Example 2

[0056] Step 1: Preparation of tungsten-copper composite powder

[0057] 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. 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 20% and a particle size of approximately 1 μm.

[0058] Step 2: Ceramic reinforced skeleton pressing

[0059] Titanium carbide powder (particle size ~200nm), tungsten-copper composite powder (~1μm), and tungsten powder (particle size ~2μm) were weighed and mixed uniformly in a mass ratio of 1:10:89. Cold isostatic pressing was used at a pressure of 80MPa and a dwell time of 4min to produce a Ø40mm diameter blank.

[0060] Step 3: Sintering of ceramic reinforced tungsten skeleton

[0061] 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 78.5%.

[0062] Step 4: Ceramic reinforced tungsten skeleton infiltrated with copper

[0063] 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.

[0064] Comparative Example 2

[0065] Step 1: Preparation of tungsten-copper composite powder

[0066] 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. 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 20% and a particle size of approximately 1 μm.

[0067] Step 2: Ceramic reinforced skeleton pressing

[0068] Weigh 500g of tungsten-copper composite powder (~1μm) and tungsten powder (~2μm) in a 10:90 mass ratio and mix them evenly. Cold isostatic pressing is used at a pressure of 80MPa and a dwell time of 4min to produce a Ø40mm diameter blank.

[0069] Step 3: Sintering of ceramic reinforced tungsten skeleton

[0070] 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 78.9%.

[0071] Step 4: Ceramic reinforced tungsten skeleton infiltrated with copper

[0072] 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.

[0073] Example 3

[0074] Step 1: Preparation of tungsten-copper composite powder

[0075] 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. 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 30% and a particle size of approximately 2 μm.

[0076] Step 2: Ceramic reinforced skeleton pressing

[0077] 500g of titanium carbide powder (particle size ~1μm), tungsten-copper composite powder (~2μm), and tungsten powder (particle size ~4μm) were weighed and mixed uniformly in a mass ratio of 1.5:5:93.5. Cold isostatic pressing was used at a pressure of 150 MPa and a dwell time of 2 minutes to obtain a Ø40mm diameter blank.

[0078] Step 3: Sintering of ceramic reinforced tungsten skeleton

[0079] 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 82.3%.

[0080] Step 4: Ceramic reinforced tungsten skeleton infiltrated with copper

[0081] 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.

[0082] Example 4

[0083] Step 1: Preparation of tungsten-copper composite powder

[0084] 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. 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 20% and a particle size of approximately 1.5 μm.

[0085] Step 2: Ceramic reinforced skeleton pressing

[0086] Weigh 500g of titanium carbide powder (particle size ~2μm), tungsten-copper composite powder (~1.5μm), and tungsten powder (particle size ~6μm) in a mass ratio of 3:15:82 and mix thoroughly. Cold isostatic pressing (CIP) is used at a pressure of 200MPa and a dwell time of 1min to produce a Ø40mm diameter blank.

[0087] Step 3: Sintering of ceramic reinforced tungsten skeleton

[0088] 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 85.4%.

[0089] Step 4: Ceramic reinforced tungsten skeleton infiltrated with copper

[0090] 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.

[0091] Example 5

[0092] Step 1: Preparation of tungsten-copper composite powder

[0093] 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. 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 20% and a particle size of approximately 1.5 μm.

[0094] Step 2: Ceramic reinforced skeleton pressing

[0095] Weigh 500g of titanium carbide powder (particle size ~2μm), tungsten-copper composite powder (~1.5μm), and tungsten powder (particle size ~6μm) in a mass ratio of 3:15:82. Mix the three powders evenly and add paraffin wax as a forming agent, with the wax accounting for 1% of the total weight of the mixed powders. Use cold isostatic pressing at a pressure of 200MPa and a dwell time of 1min to obtain a Ø40mm diameter blank.

[0096] Step 3: Sintering of ceramic reinforced tungsten skeleton

[0097] The obtained formed blank is first degreased and pre-sintered at 850°C in a hydrogen atmosphere to obtain a pre-sintered blank, and then the pre-sintered blank is sintered at 2000°C in a hydrogen atmosphere for 2 hours to obtain a ceramic reinforced tungsten skeleton with a density of 87.2%.

[0098] Step 4: Ceramic reinforced tungsten skeleton infiltrated with copper

[0099] 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.

[0100] Example 6

[0101] Step 1: Preparation of tungsten-copper composite powder

[0102] 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. 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 50% and a particle size of approximately 1.5 μm.

[0103] Step 2: Ceramic reinforced skeleton pressing

[0104] Weigh 500g of titanium carbide powder (particle size ~5μm), tungsten-copper composite powder (~1.5μm), and tungsten powder (particle size ~6μm) in a mass ratio of 5:10:85 and mix thoroughly. Cold isostatic pressing (CIP) is used at a pressure of 200MPa and a dwell time of 1min to produce a Ø40mm diameter blank.

[0105] Step 3: Sintering of ceramic reinforced tungsten skeleton

[0106] 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 88.7%.

[0107] Step 4: Ceramic reinforced tungsten skeleton infiltrated with copper

[0108] 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.

[0109] Example 7

[0110] Step 1: Preparation of tungsten-copper composite powder

[0111] 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. 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 780°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 1 μm.

[0112] Step 2: Ceramic reinforced skeleton pressing

[0113] Titanium carbide powder (particle size ~50nm), tungsten-copper composite powder (~1μm), and tungsten powder (particle size ~6μm) were weighed in a mass ratio of 3:25:72, totaling 2500g. The three powders were mixed evenly, and paraffin wax was added as a forming agent, with the weight of the paraffin wax accounting for 1.5% of the total weight of the mixed powders. Cold isostatic pressing was used at a pressure of 200MPa and a holding time of 1min to produce a blank with a diameter of Ø120mm.

[0114] Step 3: Sintering of ceramic reinforced tungsten skeleton

[0115] The obtained formed blank is first degreased and pre-sintered at 850°C in a hydrogen atmosphere to obtain a pre-sintered blank, and then the pre-sintered blank is sintered at 2000°C in a hydrogen atmosphere for 2 hours to obtain a ceramic reinforced tungsten skeleton with a density of 86.3%.

[0116] Step 4: Ceramic reinforced tungsten skeleton infiltrated with copper

[0117] The ceramic reinforced tungsten skeleton was subjected to high temperature copper infiltration treatment at 1400℃ for 1.5h to obtain a new type of tungsten infiltrated copper.

[0118] Comparative Example 3

[0119] Step 1: Ceramic reinforced skeleton pressing

[0120] Weigh 2500g of titanium carbide powder (particle size ~50nm) and tungsten powder (particle size ~6μm) in a mass ratio of 3:97, mix them evenly, and add paraffin wax as a forming agent, with the wax accounting for 1.5% of the total weight of the mixed powders. Use cold isostatic pressing at a pressure of 200MPa and a holding time of 1min to obtain a 120mm diameter blank.

[0121] Step 3: Sintering of ceramic reinforced tungsten skeleton

[0122] The obtained formed blank is first degreased and pre-sintered at 850°C in a hydrogen atmosphere to obtain a pre-sintered blank, and then the pre-sintered blank is sintered at 2000°C in a hydrogen atmosphere for 2 hours to obtain a ceramic reinforced tungsten skeleton with a density of 81.3%.

[0123] Step 4: Ceramic reinforced tungsten skeleton infiltrated with copper

[0124] The ceramic reinforced tungsten skeleton was subjected to high temperature copper infiltration treatment at 1400℃ for 15h to obtain a new type of tungsten infiltrated copper.

[0125] 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.

[0126]

[0127] It can be seen from the table that: by comparing Example 1 with Comparative Example 1, adding ultrafine tungsten-copper composite powder can improve the density of the tungsten skeleton and the room temperature and high temperature mechanical properties of the tungsten-copper infiltrated material;

[0128] Comparing Example 2 with Comparative Example 2, the introduction of TiC into the tungsten skeleton can enhance the high-temperature mechanical properties and ablation resistance of the new tungsten copper infiltrated material;

[0129] Comparing Example 7 with Comparative Example 3, adding ultrafine tungsten-copper composite powder in the preparation of large-sized samples can shorten the copper infiltration time and optimize the infiltration effect.

Claims

1. A method for preparing a tungsten copper infiltrated material, characterized in that: Tungsten 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. The method for preparing a tungsten copper infiltrated material according to claim 1, wherein: 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 tungsten copper infiltrated material according to claim 1 or 2, wherein: In the mixed powder, the mass fraction of copper is 1-6%.

4. The method for preparing a tungsten copper infiltrated material according to claim 1 or 2, wherein: 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, and the particle size of the titanium carbide powder is 30 nm-5 μm.

5. The method for preparing a tungsten copper infiltrated material according to claim 1 or 2, wherein: The mixed powder has the following components, calculated by mass percentage: 0.5-5% titanium carbide powder, 2-25% tungsten-copper composite powder, and the balance tungsten powder.

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

9. The method for preparing a tungsten copper infiltrated material according to claim 1 or 2, wherein: The temperature of the copper infiltration treatment is 1100-1400° C., and the time of the copper infiltration treatment is 0.5-4 hours.

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

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