Modified tungsten framework, high-temperature-resistant anti-ablation modified tungsten copper material and preparation method thereof

Abstract

The present application relates to a modified tungsten skeleton, a high-temperature-resistant and ablation-resistant modified tungsten-copper material, and a preparation method and application thereof. The modified tungsten skeleton is made of tungsten powder, ceramic powder and metal powder through sintering, wherein the ceramic powder accounts for 1.2-4.5% by mass percentage, the metal powder accounts for 0-10% by mass percentage, and the balance is tungsten powder. The modified tungsten-copper material comprises the modified tungsten skeleton and copper distributed in the pores of the modified tungsten skeleton. The present application adds appropriate specific ceramic powder and metal powder to tungsten powder for component design to realize modification of the tungsten-copper material and obtain the modified tungsten-copper material. The addition of appropriate ceramic powder can improve the ablation resistance and high-temperature mechanical properties of the material. The addition of appropriate metal powder can improve the tensile strength of the material and reduce the brittleness of the material, meeting the long-time use requirement in the harsh environment of the current high-temperature-resistant and ablation-resistant field, and providing a reference for the development and application prospect of similar products in the future.

Description

Technical Field

[0001] This invention relates to the field of high-temperature resistant and ablation-resistant materials technology, and in particular to a modified tungsten skeleton, a high-temperature resistant and ablation-resistant modified tungsten copper-infiltrated material, its preparation method and application. Background Technology

[0002] Tungsten-copper alloys exhibit excellent comprehensive properties in terms of thermal shock resistance, ablation and erosion resistance, high-temperature strength, and high-temperature oxidation resistance. Tungsten possesses characteristics such as a high melting point, high strength, good wear resistance and corrosion resistance, a low coefficient of linear expansion, and being a brittle material; copper possesses excellent electrical and thermal conductivity. Tungsten-copper alloys combine the advantages of both materials, exhibiting high-temperature resistance, ablation resistance, high strength, ease of machining, and sweating cooling properties, making them widely used in aerospace, machinery, and electronics industries.

[0003] With the continuous development of modern aviation and aerospace technology, higher requirements have been placed on the performance of tungsten copper-infiltrating materials. Modified tungsten copper-infiltrating materials need to be obtained through modification to have higher high-temperature strength, erosion resistance, oxidation resistance, better ablation resistance and thermal shock resistance.

[0004] The framework of modified tungsten copper-infiltrating materials is porous, and it can be used not only as a framework for tungsten copper-infiltrating materials but also as a porous material on its own. In the electronics field, it can be used as a cathode material, particularly for high-current-density cathodes. Its porous structure provides three main advantages: first, it offers uniformly distributed and effective pores for storing large amounts of active material; second, it provides a large reaction contact surface for the chemical reduction reaction between the active material and the tungsten matrix; and third, it provides an effective channel for the migration of reaction products (such as active barium) to the cathode surface. For example, it is widely used in devices such as electron tubes and gas discharge tubes. Furthermore, in the field of catalysis, it can be used as a catalyst support. The high specific surface area and abundant pore structure of the porous tungsten framework make it suitable for use as a catalyst support in various chemical reactions, improving the activity and selectivity of the catalyst.

[0005] With the continuous development of the electronics field, the requirements for emission performance are getting higher and higher, and the cathode usage environment is becoming more and more demanding. Existing conventional porous framework tungsten materials have reached their performance limits. New porous tungsten materials can achieve the addition of modified substances and improve the performance of the materials.

[0006] CN 112030025A discloses a W / WC composite grain-reinforced tungsten-copper composite material and its preparation method: a precursor solution containing tungsten salt, copper salt, and organic carbon source is spray-pyrolyzed to obtain carbon-containing tungsten-copper oxide powder; the carbon-containing tungsten-copper oxide powder is ball-milled and then reduced and carbonized in a hydrogen furnace to obtain W / WCCu composite powder; the W / WCCu composite powder is pressed into a green body and then sintered to obtain the W / WC composite grain-reinforced tungsten-copper composite material. This method uses W / WCCu composite powder to directly sinter into finished products, making it difficult to guarantee the skeletal structure and pore connectivity of the tungsten-copper material, and adversely affecting the material's sweating and cooling effect; the tungsten-copper composite material with fine tungsten particles has poor high-temperature ablation resistance; and due to the introduction of carbon, the material's high-temperature oxidation resistance and ablation resistance will be further reduced.

[0007] CN 112391565A discloses a method for preparing ZrC dispersion-reinforced tungsten-copper composite materials. Using nanoscale powder, fine-grained tungsten-copper materials are obtained through batching, ball milling, drying, forming, pre-firing, and sintering. This invention uses WCu-ZrC composite powder to achieve densification of tungsten-copper alloys at relatively low temperatures. However, the skeletal structure and pore connectivity of the prepared tungsten-copper materials are difficult to guarantee, negatively impacting the material's sweating and cooling effect and reducing its high-temperature ablation resistance.

[0008] CN 113634761A discloses a method for preparing rare earth oxide-reinforced tungsten-copper matrix composites. The rare earth oxides include at least one of yttrium, lanthanum, and cerium. A precursor is obtained by heating and stirring using tungstate, soluble rare earth salts, oxalic acid, water, and triethanolamine oleate. This precursor is then further processed in a hydrogen atmosphere in two steps to obtain W-rare earth oxide composite powder. After sintering and melt infiltration, the rare earth oxide-reinforced tungsten-copper matrix composite is obtained. The wet chemical method incorporates rare earth oxides, resulting in finer W grains during the sintering process, which negatively impacts the material's ablation resistance. Furthermore, the oxides of yttrium, lanthanum, and cerium have low melting points (2425℃, 2315℃, and 2397℃, respectively), and the addition of these rare earth oxides also reduces the material's ablation resistance.

[0009] The current state of materials used in the field of high-temperature ablation resistance does not meet the current needs, and there is an urgent need for materials with better high-temperature mechanical properties and ablation resistance.

[0010] In view of this, the present invention is hereby proposed. Summary of the Invention

[0011] The purpose of this invention is to provide a modified tungsten framework, a high-temperature resistant and ablation-resistant modified tungsten copper-infiltrating material, its preparation method, and its applications. The invention modifies the tungsten copper-infiltrating material by adding appropriate amounts of high-melting-point ceramic powder and metal powder to the raw material powder through compositional design. The appropriate addition of high-melting-point ceramics can improve the material's ablation resistance and high-temperature mechanical properties, while the addition of suitable metallic phases can increase the material's tensile strength and reduce its brittleness. This meets the current demand for long-term use in harsh environments requiring high-temperature and ablation resistance, and provides a reference for the future development and application prospects of similar products.

[0012] To achieve the above objectives, the present invention adopts the following technical solution: The first aspect of the present invention provides a modified tungsten framework, wherein the modified tungsten framework is made by sintering tungsten powder, ceramic powder and metal powder, wherein, by mass percentage, the ceramic powder accounts for 1.2-4.5%, the metal powder accounts for 0-10%, and the balance is tungsten powder; The ceramic powder is one or more of tantalum, titanium, niobium, zirconium and hafnium borides, carbides or oxides; the metal powder is one or two of molybdenum powder and rhenium powder.

[0013] Furthermore, the microcrystalline grain size of the modified tungsten framework is 7-13 grade; And / or, the modified tungsten skeleton has a high-temperature tensile strength of ≥100MPa at 1600℃, preferably 100MPa~300MPa; And / or, the room temperature tensile strength of the modified tungsten skeleton is ≥150MPa, preferably 150MPa~350MPa; And / or, the modified tungsten skeleton has a tensile strength of ≥150MPa at 1000℃, preferably 150MPa~250MPa.

[0014] A second aspect of the present invention provides a high-temperature resistant and ablation-resistant tungsten copper-infiltrating material, the material comprising: the modified tungsten skeleton described in the first aspect above and copper distributed in the pores of the modified tungsten skeleton.

[0015] Furthermore, the proportion of copper in the tungsten copper-infiltrated material is 6~12wt%.

[0016] Furthermore, the tungsten-copper-infiltrated material has a high-temperature tensile strength of ≥100MPa at 1600℃, preferably 100MPa~300MPa; And / or, the tungsten-copper infiltrated material has an ablation time of ≥210s at 2810℃, preferably 210-330s; and a mass ablation rate of ≤0.25g / s, preferably 0.10-0.21g / s.

[0017] A third aspect of the present invention provides a method for preparing the modified tungsten framework described in the first aspect, comprising the following steps: S1. Powder processing: First, tungsten-metal powder is prepared by co-reduction, and then it is mechanically mixed with ceramic powder to obtain a uniformly mixed raw material powder; or, the tungsten powder, metal powder and ceramic powder are directly mixed by mechanical mixing to obtain the raw material powder. S2. Forming: The raw material powder obtained in step S1 is pressed into shape, and then the pressed blank is shaped as needed. S3. Sintering: The pressed blank obtained in step S2 is sintered to obtain a modified tungsten skeleton.

[0018] Furthermore, in step S1, the ceramic powder is a fine powder with a D50 of 0.1~3μm; And / or, in step S1, when mixing materials directly using mechanical mixing method, ceramic powder and tungsten powder are mixed first, and then metal powder is added and mixed, with a total mixing time of 2 to 8 hours; And / or, in step S2, the pressing is cold isostatic pressing or molding, with a pressure of 180~250MPa and a holding time of 10~60min; And / or, in step S3, the sintering conditions are: atmospheric pressure sintering, sintering atmosphere is either hydrogen or argon, sintering temperature range is 1800~2400℃, and holding time is 2.5~6h.

[0019] The fourth aspect of this invention provides a method for preparing the high-temperature resistant and ablation-resistant modified tungsten copper-infiltrated material of the second aspect above, comprising the following steps: The modified tungsten framework of the first aspect described above is subjected to copper infiltration treatment, or the modified tungsten framework prepared by the method of the third aspect described above is subjected to copper infiltration treatment.

[0020] Furthermore, the copper diffusion treatment is carried out by hanging diffusion or stacking diffusion; and / or, the copper diffusion conditions are H2 atmospheric pressure copper diffusion, vacuum copper diffusion, or pressure copper diffusion in a nitrogen atmosphere; And / or, the copper is high-purity oxygen-free copper powder, copper wire, copper foil or copper plate; And / or, the copper infiltration treatment temperature is 1350~1550℃, and the holding time is 1.5~6h.

[0021] The fifth aspect of this invention provides the application of the modified tungsten framework of the first aspect or the modified tungsten framework prepared by the method of the third aspect above in the fields of electronics and / or catalysis and / or aerospace.

[0022] The modified tungsten framework, high-temperature resistant and ablation-resistant modified tungsten copper-infiltrating material, their preparation method, and applications provided by this invention have the following beneficial effects: (1) The modified tungsten skeleton provided by the present invention is a porous tungsten skeleton material. It can be used not only as a tungsten skeleton for tungsten copper infiltration materials, but also as a cathode material in the electronic field and as a catalyst support in the catalytic field. The modified tungsten skeleton has fine grains and excellent mechanical properties at room temperature and high temperature.

[0023] (2) Add appropriate amounts of specific ceramic powder and metal powder to tungsten powder to achieve tungsten copper infiltration material modification and obtain modified tungsten copper infiltration material; adding appropriate ceramic powder can improve the ablation resistance and high temperature mechanical properties of the material; adding appropriate metal powder can improve the tensile strength of the material and reduce the brittleness of the material, meet the current demand for long-term use in harsh environments in the field of high temperature resistance and ablation resistance, and provide a reference for the future development and application prospects of similar products. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a process flow diagram of one embodiment of the present invention; Figure 2 The image shows the metallographic structure of the modified tungsten copper-infiltrated material prepared in Example 5 of this invention. Figure 3 This is a SEM image of the modified novel tungsten-copper infiltrated material provided in Example 1 of the present invention; Figure 4 The XRD patterns of the modified tungsten copper-infiltrated material provided in the embodiments of the present invention are shown, wherein the black pattern is the XRD pattern of Example 1 and the red pattern is the XRD pattern of Example 4. Figure 5 This is a metallographic image of Comparative Example 3 of the present invention; Figure 6 This is a plasma ablation experiment diagram used in the performance test examples of this invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Those skilled in the art should understand that the embodiments described are merely illustrative of the invention and should not be considered as specific limitations thereof. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. Process parameters not specifically specified in the following embodiments are generally performed under conventional conditions.

[0027] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0028] According to a first aspect of the present invention, the present invention provides a modified tungsten framework, the modified tungsten framework being formed by sintering tungsten powder, ceramic powder and metal powder, wherein, by mass percentage, the ceramic powder accounts for 1.2-4.5% (e.g. 1.5%, 2%, 2.5%, 3%, 3.5%, 4%), the metal powder accounts for 0-10% (e.g. 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%), and the balance is tungsten powder; The ceramic powder is one or more of tantalum, titanium, niobium, zirconium and hafnium borides, carbides or oxides; The metal powder is one or both of molybdenum powder and rhenium powder.

[0029] If the proportion of ceramic powder is too high or too low, it will not significantly improve the ablation resistance and high-temperature mechanical properties of the material. Moreover, if the ceramic powder content is too high, it will increase the brittleness of the material, reduce its thermal conductivity, thermal shock resistance and other properties, and reduce its high-temperature performance.

[0030] The ceramic powder of this invention is preferably a boride or carbide of tantalum, titanium, niobium, zirconium, and hafnium. In particular, the inventors discovered that when the ceramic powder is a boride, the final material contains new phases such as WB and W2B. The formation and dispersion of these new phases can further improve the overall mechanical properties and ablation resistance of the material, producing unexpected effects. However, when the ceramic powder is a carbide or oxide of tantalum, titanium, niobium, zirconium, and hafnium, the final tungsten-copper-infiltrated material does not contain these new phases. Figure 4 .

[0031] The addition of appropriate amounts of molybdenum or rhenium metal powder can further improve the mechanical properties and ablation resistance of materials. However, the amount of molybdenum or rhenium metal powder added should not be too high. For example, excessive molybdenum content will result in a continuous molybdenum phase in the material skeleton, reducing the material's ablation resistance and high-temperature mechanical properties; at the same time, the molybdenum content should not be too low, as it will not have a strengthening effect.

[0032] As an optional embodiment of the modified tungsten framework of the present invention, the microcrystalline grain size of the modified tungsten framework is 7 to 13. And / or, the modified tungsten skeleton has a high-temperature tensile strength of ≥100MPa at 1600℃, preferably 100MPa~300MPa (e.g. 150MPa, 200MPa, 250MPa). And / or, the room temperature tensile strength of the modified tungsten skeleton is ≥150MPa, preferably 150MPa~350MPa (e.g. 200MPa, 250MPa, 300MPa). And / or, the modified tungsten skeleton has a tensile strength of ≥150MPa at 1000℃, preferably 150MPa~253MPa (e.g., 180MPa, 200MPa, 220MPa, 240MPa).

[0033] The tensile strength of the modified tungsten skeleton at 1600℃ can be referenced from the value of the tungsten copper-infiltrated material after copper removal from the skeleton, which is greater than 100MPa. This is because the modified tungsten copper-infiltrated material of this invention is actually composed of skeleton and copper. The melting point of copper is 1084℃, and the test temperature of 1600℃ is much higher than the melting point of the material. The test environment is a vacuum atmosphere, and the test process involves heating and holding time. The copper in the material, especially the copper in the test section, is basically completely melted and volatilized, leaving only the skeleton.

[0034] According to a second aspect of the present invention, the present invention provides a high-temperature resistant and ablation-resistant modified tungsten copper-infiltrated material, comprising: the modified tungsten skeleton described in the first aspect and copper distributed in the pores of the modified tungsten skeleton.

[0035] As an optional embodiment of the high-temperature resistant and ablation-resistant modified tungsten copper-infiltrating material of the present invention, the proportion of copper in the tungsten copper-infiltrating material is 6~12wt% (e.g., 7%, 8%, 9%, 10%, 11%).

[0036] As an optional embodiment of the high-temperature resistant and ablation-resistant tungsten copper-infiltrated material of the present invention, the ablation time of the tungsten copper-infiltrated material at 2810℃ is ≥210s, preferably 210-330s (e.g., 230s, 250s, 270s, 290s, 310s); the mass ablation rate is ≤0.25g / s, preferably 0.10-0.21g / s (e.g., 0.3g / s, 0.5g / s, 0.7g / s, 0.9g / s, 1.1g / s, 1.3g / s, 1.5g / s, 1.7g / s, 1.9g / s).

[0037] This invention modifies tungsten copper-infiltrating materials by adding ceramic powder and metal powder to tungsten powder and designing the composition of the raw material powder. The addition of appropriate ceramic powder can improve the ablation resistance and high-temperature mechanical properties of the material, while the addition of appropriate metal powder can improve the tensile strength and reduce the brittleness of the material.

[0038] According to a third aspect of the present invention, the present invention provides a method for preparing the modified tungsten framework described in the first aspect, comprising the following steps: S1. Powder processing: First, tungsten-metal powder is prepared by co-reduction, and then it is mechanically mixed with ceramic powder to obtain a uniformly mixed modified raw material powder; or, the raw material powder is obtained by directly mixing tungsten powder, metal powder and ceramic powder using a mechanical mixing method. S2. Forming: The modified raw material powder obtained in step S1 is pressed into shape, and then the pressed blank is shaped as needed. S3. Sintering: The pressed blank obtained in step S2 is sintered to obtain a modified tungsten skeleton.

[0039] In this invention, the purpose of shaping is to make the blank after cold isostatic pressing have a flat appearance, uniform thickness, and symmetrical spatial dimensions, which is beneficial to uniform shrinkage during subsequent sintering.

[0040] As an optional embodiment of the preparation method of the modified tungsten framework of the present invention, In step S1, the ceramic powder is fine powder with a D50 of 0.1~3μm; And / or, in step S1, when mixing materials directly using mechanical mixing method, ceramic powder and tungsten powder are mixed first, and then metal powder is added and mixed, with a total mixing time of 2 to 8 hours; And / or, in step S2, the pressing is cold isostatic pressing or molding, with a pressure of 180~250MPa (e.g., 200MPa, 220MPa, 240MPa) and a holding time of 10~60min (e.g., 20min, 30min, 40min, 50min). And / or, in step S3, the sintering conditions are: atmospheric pressure sintering, sintering atmosphere is either hydrogen or argon, sintering temperature range is 1800~2400℃ (1900℃, 2000℃, 2100℃, 2200℃, 2300℃), and holding time is 2.5~6h (e.g., 3h, 4h, 5h).

[0041] In one embodiment of the present invention, the cold isostatic pressing process in the S2 forming step involves loading the dried powder into a rubber sleeve, then into a pressing mold with a core, immersing it in an oil cylinder to obtain a pressed blank; after cold isostatic pressing, the mold and other tooling are removed, and the pressed blank is shaped. In step S3, sintering can be carried out, but is not limited to, in heating equipment such as a sintering furnace.

[0042] Furthermore, based on the preparation method of the high-temperature resistant and ablation-resistant modified tungsten copper-infiltrating material provided in the fourth aspect below, a modified tungsten skeleton can also be obtained by high-temperature copper removal of the obtained tungsten copper-infiltrating material. The high-temperature copper removal refers to heating the tungsten copper-infiltrating material in a vacuum environment to above the melting point of copper, causing all the copper to melt and volatilize.

[0043] According to a fourth aspect of the present invention, the present invention provides a method for preparing the high-temperature resistant and ablation-resistant modified tungsten copper-infiltrated material described in the second aspect, comprising the following steps: The modified tungsten framework described in the first aspect is subjected to copper infiltration treatment, or the modified tungsten framework prepared by the method described in the third aspect is subjected to copper infiltration treatment.

[0044] The copper infiltration is carried out by placing the obtained sintered blank or modified tungsten skeleton on a hanger or in a graphite boat, using a hanging infiltration or stacking infiltration method.

[0045] As an optional embodiment of the preparation method of the high-temperature resistant and ablation-resistant modified tungsten copper-infiltrating material according to the fourth aspect of the present invention, the copper infiltrating treatment is carried out by hanging infiltrating or stacking infiltrating. And / or, the copper diffusion conditions are H2 atmospheric pressure copper diffusion, vacuum copper diffusion, or pressure copper diffusion in a nitrogen atmosphere; And / or, the copper is high-purity oxygen-free copper powder, copper wire, copper foil or copper plate; And / or, the temperature of the copper infiltration treatment is 1350~1550℃ (e.g., 1400℃, 1450℃, 1500℃), and the holding time is 1.5~6h (e.g., 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h).

[0046] In one embodiment of the present invention, when using the copper infiltration process, the workpiece is first suspended with a molybdenum wire, the required copper content is calculated and added to a crucible, and then the workpiece is suspended into the copper infiltration furnace and fired in a high-purity hydrogen atmosphere. The temperature in the high-temperature zone is 1350~1550℃ (e.g., 1400℃, 1450℃, 1500℃), and the holding time is 1.5~4.5h (e.g., 2h, 2.5h, 3h, 3.5h, 4h). In one embodiment of the present invention, when copper is impregnated by suspension, a vacuum is first drawn to remove gas from the workpiece, and then the workpiece is heated to 1350~1550℃ (e.g., 1400℃, 1450℃, 1500℃) to perform copper melting and copper soaking. Then, pressure-type copper immersion is performed to achieve uniform pressure immersion of copper liquid in all directions. The pressure and temperature holding time is 1.5~6h (e.g., 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h). After copper immersion, pressure-type cooling is performed.

[0047] According to a fifth aspect of the present invention, the present invention provides applications of the modified tungsten framework described in the first aspect or the modified tungsten framework obtained by the preparation method of the third aspect in the fields of electronics and / or catalysis and / or aerospace.

[0048] The present invention will now be described in further detail with reference to specific embodiments and comparative examples.

[0049] The particle sizes of the raw material powders used in the following examples are as follows: Tungsten powder: Fisher particle size 6.5μm; HfB2 powder: Laser-etched particle size distribution exhibits a unimodal distribution (D50): 2.5~3.5μm. HfC: Laser particle size distribution exhibits a unimodal distribution; D50: 2.5~3.5μm. TaC: Laser-induced particle size distribution exhibits a unimodal distribution; D50: 2.5~3.5μm. Re powder: Laser particle size distribution D50: 15-16μm, Example 1 The preparation method of W-2HfB2-3Re-Cu in this embodiment includes the following steps: (1) Preparation of raw material powder: Weigh 47.5 kg of tungsten powder, 1 kg of HfB2 powder and 1.5 kg of Re powder, mix the tungsten powder, ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder; (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is loaded into the sintering furnace and held at 2200℃ for 270 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact with a room temperature tensile strength of 310 MPa and a 1000℃ tensile strength of 220 MPa. (4) Copper infiltration: Place the sintered billet obtained in step (3) on the hanger, hang the workpiece with molybdenum wire and then hang the workpiece into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by hanging infiltration. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0050] Example 2 The preparation method of W-2HfB2-Cu in this embodiment includes the following steps: (1) Preparation of raw material powder: Weigh 49 kg of tungsten powder and 1 kg of HfB2 powder, and mix the tungsten powder and ceramic powder on a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder; (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 20min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2080℃ for 360 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact; its room temperature tensile strength is 280MPa and its 1000℃ tensile strength is 190MPa. (4) Copper infiltration: Place the sintered billet obtained in step (3) on the hanger, hang the workpiece with molybdenum wire and then hang the workpiece into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by hanging infiltration. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0051] Example 3 The preparation method of W-1.2TaC-5Re-Cu in this embodiment includes the following steps: (1) Preparation of raw material powder: Weigh 46.9 kg of tungsten powder, 0.6 kg of TaC powder and 2.5 kg of Re powder, and mix the tungsten powder, ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder; (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 15min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2100℃ for 360 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact. (4) Copper infiltration: Place the sintered billet obtained in step (3) on the material placement platform and place it in the copper infiltration furnace. After vacuuming, heat it to 1200°C. After the copper melts, immerse the workpiece in it and then pressurize it with N2. After the pressure reaches 5MPa, keep it at the temperature for 120 minutes. After cooling to room temperature, release the pressure and remove it from the furnace.

[0052] Example 4 The preparation method of W-1.2HfC-5Re-Cu in this embodiment includes the following steps: (1) Preparation of raw material powder: Weigh 46.9 kg of tungsten powder, 0.6 kg of HfC powder and 2.5 kg of Re powder, and mix the tungsten powder, ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder; (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2100℃ for 300 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact. (4) Copper infiltration: The obtained sintered billet is placed on a hanger, and the workpiece is suspended by a molybdenum wire and then suspended into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by suspension. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0053] Example 5 The preparation method of W-2HfC-3Re-Cu in this embodiment (1) Preparation of raw material powder: Weigh 47.5 kg of tungsten powder, 1 kg of HfC powder, and 1.5 kg of Re powder. Mix the tungsten powder, ceramic powder, and rhenium powder in a three-dimensional mixer for 6 hours to obtain a uniformly mixed raw material powder. (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2700℃ for 300 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact; its room temperature tensile strength is 320 MPa and its 1000℃ tensile strength is 250 MPa. (4) Copper infiltration: Place the sintered billet obtained in step (3) on the hanger, hang the workpiece with molybdenum wire and then hang the workpiece into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by hanging infiltration. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0054] Example 6 The preparation method of W-2HfO2-3Re-Cu in this embodiment is as follows: (1) Preparation of raw material powder: Weigh 47.5 kg of tungsten powder, 1 kg of HfO2 powder, and 1.5 kg of Re powder. Mix the tungsten powder, ceramic powder, and rhenium powder in a three-dimensional mixer for 6 hours to obtain a uniformly mixed raw material powder. (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2100℃ for 270 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact. (4) Copper infiltration: Place the sintered billet obtained in step (3) on the hanger, hang the workpiece with molybdenum wire and then hang the workpiece into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by hanging infiltration. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0055] Example 7 The preparation method of W-4HfB2-3Re-Cu in this embodiment is as follows: (1) Preparation of raw material powder: Weigh 46.5 kg of tungsten powder, 2 kg of HfB2 powder and 1.5 kg of Re powder, mix the tungsten powder, ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder; (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2000℃ for 270 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact. (4) Copper infiltration: Place the sintered billet obtained in step (3) on the hanger, hang the workpiece with molybdenum wire and then hang the workpiece into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by hanging infiltration. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0056] Example 8 The preparation method of W-3TiB2-7Re-Cu in this embodiment is as follows: (1) Preparation of raw material powder: Weigh 45kg of tungsten powder, 1.5kg of TiB2 powder and 3.5kg of Re powder, and mix the tungsten powder, ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder; (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2100℃ for 200 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact. (4) Copper infiltration: Place the sintered billet obtained in step (3) on the hanger, hang the workpiece with molybdenum wire and then hang the workpiece into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by hanging infiltration. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0057] Example 9 The preparation method of W-3NbB2-7Mo-Cu in this embodiment is as follows: (1) Preparation of raw material powder: Weigh 45 kg of tungsten powder, 1.5 kg of NbB2 powder and 3.5 kg of Mo powder, mix the tungsten powder, ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder; (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2200℃ for 300 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact. (4) Copper infiltration: Place the sintered billet obtained in step (3) on the hanger, hang the workpiece with molybdenum wire and then hang the workpiece into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by hanging infiltration. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0058] Example 10 The preparation method of W-3ZrB2-7Re-Cu in this embodiment is as follows: (1) Preparation of raw material powder: Weigh 45kg of tungsten powder, 1.5kg of ZrB2 powder and 3.5kg of Re powder, and mix the tungsten powder, ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder; (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2200℃ for 200 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact. (4) Copper infiltration: Place the sintered billet obtained in step (3) on the hanger, hang the workpiece with molybdenum wire and then hang the workpiece into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by hanging infiltration. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0059] Comparative Example 1 The preparation method of this comparative example W-Cu includes the following steps: (1) Take 100 kg of tungsten powder for loading; (2) Forming: The cold isostatic pressing process is adopted. The dried tungsten powder is put into a rubber sleeve, then into a pressing mold with a core, and immersed in an oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. (3) Sintering: The pressed blank obtained in step (2) is loaded into the sintering furnace and held at 2000℃ for 300 min in a high-purity hydrogen atmosphere to obtain a tungsten skeleton sintered blank; (4) Copper infiltration: The obtained sintered billet is placed on a hanger, and the workpiece is suspended by a molybdenum wire and then suspended into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by suspension. The copper infiltration temperature is maintained at 1500℃ and the holding time is 90min.

[0060] Comparative Example 2 The preparation method of this comparative example (W-5HfB2-3Re)-Cu includes the following steps: (1) Preparation of raw material powder: Weigh 46 kg of tungsten powder, 2.5 kg of HfB2 powder and 1.5 kg of Re powder, and mix the tungsten powder, modified ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder. (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2000℃ for 270 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact. (4) Copper infiltration: The obtained sintered billet is placed on a hanger, and the workpiece is suspended by a molybdenum wire and then suspended into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by suspension. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0061] Comparative Example 3 The preparation method of this comparative example (W-5HfB2-3Re)-Cu includes the following steps: (1) Preparation of raw material powder: Weigh 46 kg of tungsten powder, 2.5 kg of HfB2 powder and 1.5 kg of Re powder, and mix the tungsten powder, modified ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder. (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2200℃ for 270 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact. (4) Copper infiltration: The obtained sintered billet is placed on a hanger, and the workpiece is suspended by a molybdenum wire and then suspended into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by suspension. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0062] Comparative Example 4 The preparation method of this comparative example W-0.5HfC-3Re-Cu includes the following steps: (1) Preparation of raw material powder: Weigh 48.25 kg of tungsten powder, 0.25 kg of HfC powder and 1.5 kg of Re powder, and mix the tungsten powder, modified ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder; (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is loaded into the sintering furnace and held at 2100℃ for 300 min in a high-purity hydrogen atmosphere to obtain the modified tungsten skeleton compact. (4) Copper infiltration: The obtained sintered billet is placed on a hanger, and the workpiece is suspended by a molybdenum wire and then suspended into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by suspension. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0063] Performance testing The materials obtained in Examples 1-10 and Comparative Examples 1-4 of this invention were subjected to copper content testing, tensile strength at 1600℃ and ablation resistance testing.

[0064] The copper content test adopts the national standard GJB2299; The tensile strength at 1600℃ conforms to the national standards GB / T228.2 and GJB2299. The ablation performance test was conducted using a plasma ablation device, see [link / reference]. Figure 6 The ablation performance of the material was tested at 2810℃. The ablation test method followed the requirements of GJB323A-96 standard, but the heat source was a plasma gun, which generated a plasma flame perpendicular to the circular surface of the specimen. The tip of the flame was aligned with the center of the specimen, and an infrared thermometer was used to measure the temperature throughout the experiment. The temperature was transmitted back to the temperature control system, which maintained a constant temperature at the center of the specimen by adjusting the distance between the plasma gun and the specimen. The specimen was ablated along its thickness, and the experiment stopped when the specimen burned through. The time taken from the specimen reaching the specified test temperature to burning through was recorded as "ablation resistance time (t)". ​​The weights before and after the test were recorded as M1 and M2, respectively. The mass ablation rate can be expressed as (M1-M2) / t. The specimen for the ablation resistance test was a 5mm thick circular piece. The ablation test was conducted perpendicular to the thickness direction, and the ablation test ended when the specimen burned through.

[0065] Results data The performance test results are shown in Table 1: Table 1 As can be seen from the table above, compared with conventional tungsten copper infiltrated materials (Comparative Example 1), the modified tungsten copper infiltrated materials prepared in this invention have significantly improved high-temperature strength, with a tensile strength of up to 268 MPa in a vacuum atmosphere at 1600℃; the ablation resistance is significantly improved, with the ablation time being nearly twice that of conventional grade tungsten copper (W-7Cu), reaching 327 s; the ablation mass loss is significantly reduced, with an ablation rate as low as 0.11 g / s.

[0066] Furthermore, a comparison of Comparative Examples 2-4 with Example 1 in the table above shows that adding too much or too little ceramic powder will have an adverse effect on the ablation resistance and mechanical properties of the material.

[0067] from Figure 3As can be seen from the scanning electron microscope images of the modified tungsten copper-infiltrated material prepared in Example 1, the material has the typical structure of tungsten copper material, consisting of a framework and copper; the gray-contrast part is the framework, which is a granular or blocky structure, and these particles play a role in reinforcement and support in the material; the black-contrast part is the copper matrix surrounding the tungsten particles; the diffusely distributed dark gray part is the WB new phase.

[0068] from Figure 2 As can be seen, the modified tungsten-copper infiltrated material prepared in Example 5 has the typical structure of tungsten-copper materials, consisting of a framework and copper. The gray part is the framework, which is a granular or blocky structure. These particles play a reinforcing and supporting role in the material. The golden-yellow part is a copper matrix surrounding the tungsten particles. The grain size of the tungsten framework is around 10.

[0069] from Figure 4 The XRD patterns show that new phases, including WB and W2B, are formed in HfB2 and rhenium-modified tungsten copper materials (Example 1). These new phases enhance the mechanical properties and ablation resistance of the original composition, and improve the stability of the material properties. In contrast, no new phases are formed in HfC and rhenium-modified materials (Example 4), and the stability of the material properties is poor.

[0070] from Figure 5 As can be seen, there are more black areas in Comparative Example 3. This is because the increased amount of hafnium boride produces too much WB phase, which leads to a certain degree of reduction in the ablation resistance of the material.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-temperature resistant and ablation-resistant tungsten copper-infiltrated material, characterized in that, include: Modified tungsten framework and copper distributed in the pores of the modified tungsten framework; The copper content in the tungsten-copper-infiltrated material is 6~12 wt%. The modified tungsten framework is made by sintering tungsten powder, ceramic powder and metal powder or by sintering tungsten powder and ceramic powder. The ceramic powder accounts for 1.2-4.5% by mass percentage, the metal powder accounts for 0-10%, and the balance is tungsten powder. The ceramic powder is one or more of tantalum, titanium, niobium, zirconium and hafnium borides, carbides or oxides; The metal powder is one or both of molybdenum powder and rhenium powder; The microcrystalline grain size of the modified tungsten framework is 7-13. The modified tungsten skeleton has a high-temperature tensile strength of 100MPa~300MPa at 1600℃; The modified tungsten skeleton has a room temperature tensile strength of 150 MPa to 350 MPa; The modified tungsten skeleton has a tensile strength of 150MPa~250MPa at 1000℃.

2. The high-temperature resistant and ablation-resistant tungsten copper-infiltrated material according to claim 1, characterized in that, The tungsten-copper infiltrated material has a high-temperature tensile strength of 100MPa~300MPa at 1600℃; And / or, the tungsten-copper infiltrated material has an ablation time of ≥210s at 2810℃; Mass ablation rate ≤ 0.25 g / s.

3. A method for preparing a modified tungsten framework, characterized in that, The modified tungsten framework is made by sintering tungsten powder, ceramic powder and metal powder or by sintering tungsten powder and ceramic powder. The ceramic powder accounts for 1.2-4.5% by mass percentage, the metal powder accounts for 0-10%, and the balance is tungsten powder. The ceramic powder is one or more of tantalum, titanium, niobium, zirconium and hafnium borides, carbides or oxides; The metal powder is one or both of molybdenum powder and rhenium powder; The microcrystalline grain size of the modified tungsten framework is 7-13. The modified tungsten skeleton has a high-temperature tensile strength of 100MPa~300MPa at 1600℃; The modified tungsten skeleton has a room temperature tensile strength of 150 MPa to 350 MPa; The modified tungsten skeleton has a tensile strength of 150MPa~250MPa at 1000℃; The method for preparing the modified tungsten framework includes the following steps: S1. Powder processing: First, tungsten-metal powder is prepared by co-reduction, and then mechanically mixed with ceramic powder to obtain a uniformly mixed raw material powder; or, the raw material powder is obtained by directly mixing tungsten powder, metal powder and ceramic powder using a mechanical mixing method; the ceramic powder is fine powder with a D50 of 0.1~3μm; when directly using the mechanical mixing method, the ceramic powder is first mixed with tungsten powder, and then metal powder is added and mixed, with a total mixing time of 2~8h; S2. Forming: The raw material powder obtained in step S1 is pressed into shape, and then the pressed blank is shaped as needed; the pressing is cold isostatic pressing or molding, with a pressure of 180~250MPa and a holding time of 10~60min. S3. Sintering: The pressed blank obtained in step S2 is sintered to obtain a modified tungsten skeleton. The sintering conditions are: atmospheric pressure sintering, sintering atmosphere is either hydrogen or argon, sintering temperature range is 1800~2400℃, and holding time is 2.5~6h.

4. A method for preparing a high-temperature resistant and ablation-resistant tungsten copper-infiltrated material as described in claim 1 or 2, characterized in that, Includes the following steps: The modified tungsten framework described in claim 1 or 2 is subjected to copper infiltration treatment.

5. The preparation method of the high-temperature resistant and ablation-resistant tungsten copper-infiltrated material according to claim 4, characterized in that, The copper diffusion treatment is carried out by hanging diffusion or stacking diffusion; and / or, the conditions of the copper diffusion treatment are H2 atmospheric pressure copper diffusion, vacuum copper diffusion or pressure copper diffusion in a nitrogen atmosphere. And / or, the copper is high-purity oxygen-free copper powder, copper wire, copper foil, or copper plate; And / or, the copper infiltration treatment temperature is 1350~1550℃, and the holding time is 1.5~6h.

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