Tungsten-rhenium infiltrated copper gradient material and preparation method thereof

Abstract

The invention discloses a preparation method of a tungsten-rhenium infiltrated copper gradient material. The preparation method comprises the following steps: step 1, selecting tungsten powder with three particle size ranges; 2, three kinds of tungsten-rhenium alloy powder are prepared; 3, the three kinds of tungsten-rhenium alloy powder obtained in the step 2 and the tungsten fiber net are sequentially loaded into a forming rubber sleeve according to the particle size level from small to large, a cold isostatic press is adopted for compression forming, and a green body is obtained; 4, the green body is placed in a hydrogen sintering furnace to be subjected to framework forming sintering; 5, allowing the gradient surface of the sintered blank to be parallel to the bottom of the graphite boat for copper infiltration, reserving the thickness of a pure copper layer in the length direction of the graphite boat, and ensuring that the length size of the graphite boat is the height of the gradient layer of the sintered blank plus the thickness of a compact copper layer; and 6, the four-layer tungsten-rhenium copper infiltrated gradient material of a tungsten-rhenium alloy layer, a tungsten-rhenium-less-copper layer, a tungsten-rhenium-more-copper layer and a pure copper layer is obtained. The method solves the problem that in the prior art, one-time preparation cannot be achieved. The invention further discloses the tungsten-rhenium infiltrated copper gradient material.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of gradient metal materials for plasma-facing components of nuclear fusion reactors, and in particular relates to a tungsten-rhenium-copper-infiltrated gradient material, and also relates to a preparation method of the tungsten-rhenium-copper-infiltrated gradient material. Background Art

[0002] The first wall of the blanket and the divertor in the magnetic confinement nuclear fusion reactor are plasma-facing components (PFCs) that directly face the plasma. During the service process, the components will be subjected to steady-state heat flow, transient thermal shock, and high-energy fusion neutron irradiation. The known materials cannot fully meet the requirements of plasma-facing materials (PFM). Tungsten and its alloys have the characteristics of high melting point, high thermal conductivity, low sputtering rate and low tritium retention, which are the best choice after compromise of plasma-facing materials PFM. The plasma-facing components PFCs are composed of plasma-facing materials PFM and heat sink materials. The high thermal conductivity of copper is widely used as a heat sink material. Due to the large difference in thermal expansion coefficient and Young's modulus between W and Cu, high thermal stress will be generated at their interface under high temperature conditions, which may lead to cracking and other forms of failure due to low tensile strength of the W / Cu interface, seriously affecting the service life of PFCs. In order to alleviate the thermal stress at the interface between W and Cu, W-Cu functional gradient materials (FGM) as connecting materials or substitute materials between the two are particularly urgent.

[0003] At present, the preparation methods of W-Cu functional gradient materials are: 1. A porous tungsten skeleton is prepared by laser selective melting, and then copper is filled by infiltration to prepare W-Cu functional gradient materials, such as "A gradient tungsten-copper composite material and its preparation method", patent publication number: CN 106475563A, publication time: 2017.03.08; "A method for preparing a tungsten-copper gradient composite material", patent publication number: CN 113084166A, publication time: 2021.07.09; 2. A tungsten-copper composite powder is first prepared by a chemical method, and then the W-Cu functional gradient material is prepared by cold isostatic pressing or hot isostatic pressing, such as "A tungsten-copper functional gradient material and its preparation method", patent publication number: CN 115178740 A, publication time: 2022.10.14; such as "A tungsten-copper functional gradient material and its preparation method, switch", patent publication number: CN 118045994 A. Publication date: 2024.05.17. The disadvantages of the above-mentioned preparation method 1 are that the laser selective melting molding method has high cost and large pores, resulting in the non-dispersed distribution of copper in a small size range, which in turn affects the heat conduction efficiency; the disadvantage of preparation method 2 is that the preparation process of the composite powder is complicated and costly; at the same time, both methods cannot prepare a gradient material composed of three structures of pure tungsten, tungsten copper and pure copper at one time. Summary of the invention

[0004] The first object of the present invention is to provide a method for preparing a tungsten-rhenium-copper-infiltrated gradient material, which solves the problems of the prior art that the material cannot be prepared in one go and the W / Cu interface has low tensile strength.

[0005] The second object of the present invention is to provide a tungsten-rhenium-copper-infiltrated gradient material prepared by the above method.

[0006] The first technical solution adopted by the present invention is a method for preparing a tungsten-rhenium-copper-infiltrated gradient material, comprising the following steps:

[0007] Step 1, selecting tungsten powders of three particle size ranges;

[0008] Step 2, mixing the tungsten powders of different particle size ranges selected in step 1 with ammonium perrhenate solution respectively to prepare three types of tungsten-rhenium alloy powders;

[0009] Step 3, the three kinds of tungsten-rhenium alloy powders and the tungsten fiber mesh obtained in step 2 are sequentially loaded into the molding rubber sleeve according to the particle size level from small to large, and pressed by a cold isostatic press to obtain a green body;

[0010] Step 4, placing the green body in a hydrogen sintering furnace for skeleton forming and sintering;

[0011] Step 5, placing the copper infiltrated with the gradient surface of the sintered blank parallel to the bottom of the graphite boat, and reserving the thickness of the pure copper layer in the length direction of the graphite boat to ensure that the length of the graphite boat is the height of the gradient layer of the sintered blank plus the thickness of the dense copper layer;

[0012] Step 6, mechanically processing the infiltrated blank to obtain four layers of tungsten-rhenium copper-infiltrated gradient material, namely, a tungsten-rhenium alloy layer, a tungsten-rhenium-low copper layer, a tungsten-rhenium-high copper layer and a pure copper layer.

[0013] The present invention is also characterized in that:

[0014] In step 1, the three particle size ranges of tungsten powder are respectively: fine particle size 1-3 μm, medium particle size 3-8 μm, and coarse particle size 6-12 μm.

[0015] Step 2 is specifically as follows: Preparation of tungsten-rhenium alloy powder: selecting ammonium perrhenate with a purity of 3-5N, using a constant temperature water bath, using deionized water as a solvent and ammonium perrhenate as a solute, placing tungsten powder in an ammonium perrhenate solution according to the required tungsten: rhenium weight ratio of 92-99:8-1, wherein the volume of the solvent is 1-5 times the volume of the tungsten powder; stirring at a constant temperature of 60°C to 100°C, and after complete volatilization, obtaining ammonium perrhenate-coated tungsten powder; drying the ammonium perrhenate-coated powder in a drying oven at 100°C to 400°C for 6h to 10h, and the dried powder is crushed by ball milling for 3h to 6h, with a ball-to-material ratio of 2:1 and a rotation speed of 100r / min to 300r / min, to obtain a uniformly dispersed tungsten-rhenium alloy powder;

[0016] The tungsten powder placed in the ammonium perrhenate solution is fine-grained tungsten powder, medium-grained tungsten powder or coarse-grained tungsten powder; the three tungsten powders are prepared respectively by the same tungsten-rhenium alloy powder preparation method mentioned above.

[0017] Step 3 is specifically as follows: firstly lay the fine-grained tungsten-rhenium alloy powder on the bottom layer of the molding rubber sleeve with a thickness of 3mm to 6mm, then lay a layer of tungsten fiber mesh, and then add a layer of tungsten fiber mesh at a height of 1mm to 3mm for each powder, and after laying the fine-grained tungsten-rhenium alloy powder, still add a layer of tungsten fiber mesh at a height of 1mm to 3mm for each powder, and then lay the medium-grained tungsten-rhenium alloy powder and the coarse-grained tungsten-rhenium alloy powder in turn, and finally use a cold isostatic press to press and shape to obtain a green body;

[0018] Among them, the laying spacing of the tungsten fiber mesh is 1mm~3mm, the wire diameter of the tungsten fiber mesh is 10μm~50μm, and the mesh number is 10 mesh~100 mesh; a cold isostatic press is used to maintain the pressure at 150MPa~300MPa for 30min~90min.

[0019] Step 4 is specifically as follows: pressing and sintering the green body: the sintering method is to place the fine-grained tungsten-rhenium alloy powder at the bottom and the coarse-grained tungsten-rhenium alloy powder at the top vertically, using a medium-frequency sintering furnace in a hydrogen atmosphere, keeping the temperature at 600°C to 1000°C for 1h to 4h during the heating stage, and keeping the temperature at 1800°C to 2300°C for 6h to 12h during the insulation stage; to complete the further reduction of the rhenium oxide in the coating layer;

[0020] Step 5 is specifically as follows: design the size of the graphite boat according to the size of the sintered blank. During melt infiltration, the inner length L of the graphite boat needs to be determined in combination with the height h of the sintered blank to ensure that the coarse-grained sintered end of the sintered blank obtains a pure copper layer of designed thickness after the melt infiltration is completed. The inner width W of the graphite boat needs to be determined in combination with the length l of the sintered blank, and the inner height H of the graphite boat needs to be determined in combination with the width w of the sintered blank. Use the buried infiltration method for copper infiltration, and the amount of copper used is the volume of the graphite boat minus the volume of the sintered blank, that is, the required copper volume. The sintering temperature of the melt infiltration furnace is 1100℃~1500℃, and the insulation is 4h~8h.

[0021] Step 6 is specifically as follows: after the infiltration is completed, the sintered blank is machined to remove the excess copper on the outside of the sintered blank, retaining the coarse-grained pure copper layer at the sintered end, and obtaining a four-gradient tungsten-rhenium copper infiltrated gradient material consisting of a tungsten-rhenium alloy layer, a tungsten-rhenium-low copper layer, a tungsten-rhenium-high copper layer and a pure copper layer.

[0022] The second technical solution adopted by the present invention is that the tungsten-rhenium copper-infiltrated gradient material includes a tungsten-rhenium alloy layer, a tungsten-rhenium-less copper layer, a tungsten-rhenium-more copper layer and a pure copper layer arranged in sequence, which is prepared by the above method.

[0023] The beneficial effects of the present invention are:

[0024] The tungsten-rhenium-copper-infiltrated gradient material prepared by the method of the present invention has a tungsten-rhenium-copper layer in the middle, and the copper content is flexible and variable, and the particle size of the tungsten powder can be adjusted according to actual needs; the tungsten-rhenium alloy has higher high-temperature strength and plasma etching resistance than pure tungsten; the tungsten fiber mesh gives full play to the excellent properties of the fiber itself to improve the toughness of the material; a dense pure tungsten-rhenium alloy layer is obtained in the sintering process, and a tungsten-rhenium alloy skeleton with the required porosity is obtained at the same time, and copper fills the pores inside the skeleton during the infiltration process, so that a high-strength combination of pure tungsten-rhenium alloy and tungsten-rhenium-copper, and a high-strength combination of tungsten-rhenium-copper and pure copper are obtained at one time, avoiding the existing material to realize the combination of pure tungsten and tungsten-copper transition layer, and the combination of tungsten-copper transition layer and pure copper respectively through two hot isostatic pressing methods, which is beneficial to solving the actual needs of materials for thermonuclear fusion plasma-oriented components. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the state of placing the sintered blank into a graphite boat during the infiltration of the sintered blank in step 5 of the method of the present invention;

[0026] Figure 2The figure is a schematic diagram of the structure of the tungsten-rhenium-copper-infiltrated gradient material obtained by the method of the present invention.

[0027] In the figure, 1. tungsten-rhenium alloy layer, 2. porous tungsten-rhenium skeleton a, 3. porous tungsten-rhenium skeleton b, 4. reserved pure copper layer space, 5. tungsten-rhenium-less copper layer, 6. tungsten-rhenium-more copper layer, 7. pure copper layer. DETAILED DESCRIPTION

[0028] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] The present invention provides a method for preparing a tungsten-rhenium-copper-infiltrated gradient material, comprising the following steps:

[0030] Step 1, selecting tungsten powders of three particle size ranges;

[0031] In step 1, the three particle size ranges of tungsten powder are respectively: fine particle size 1-3 μm, medium particle size 3-8 μm, and coarse particle size 6-12 μm.

[0032] The sintering density of fine-grained tungsten powder at 1800-2300℃ should be ≥98%. The particle size of medium-grained and coarse-grained tungsten powder should be adjusted at the same sintering temperature to ensure the required sintering skeleton porosity.

[0033] Step 2, mixing the tungsten powders of different particle size ranges selected in step 1 with ammonium perrhenate solution respectively to prepare three types of tungsten-rhenium alloy powders;

[0034] Step 2 is as follows:

[0035] Preparation of tungsten-rhenium alloy powder: select ammonium perrhenate with a purity of 3-5N, use a constant temperature water bath, use deionized water as solvent and ammonium perrhenate as solute, and place tungsten powder in ammonium perrhenate solution according to the required tungsten:rhenium weight ratio of (92-99): (8-1), wherein the volume of the solvent is 1-5 times the volume of the tungsten powder; stir at a constant temperature of 60°C-100°C, and wait for complete volatilization to obtain ammonium perrhenate coated tungsten powder; dry the ammonium perrhenate coated powder in a drying oven at 100°C-400°C for 6h-10h, and the dried powder is crushed by ball milling for 3h-6h, with a ball-to-material ratio of 2:1 and a rotation speed of 100r / min-300r / min to obtain a uniformly dispersed tungsten-rhenium alloy powder;

[0036] The tungsten powder placed in the ammonium perrhenate solution is fine-grained tungsten powder, medium-grained tungsten powder or coarse-grained tungsten powder; the three tungsten powders are prepared respectively by the same tungsten-rhenium alloy powder preparation method mentioned above;

[0037] Step 3, the three kinds of tungsten-rhenium alloy powders and the tungsten fiber mesh obtained in step 2 are sequentially loaded into the molding rubber sleeve according to the particle size level from small to large, and pressed by a cold isostatic press to obtain a green body;

[0038] Step 3 is as follows:

[0039] The fine-grained tungsten-rhenium alloy powder is first laid on the bottom layer of the molding rubber sleeve with a thickness of 3mm to 6mm, and then a layer of tungsten fiber mesh is laid, and then a layer of tungsten fiber mesh is added at a height of 1mm to 3mm for each powder. After the fine-grained tungsten-rhenium alloy powder is laid, a layer of tungsten fiber mesh is still added at a height of 1mm to 3mm for each powder, and then medium-grained tungsten-rhenium alloy powder and coarse-grained tungsten-rhenium alloy powder are laid in sequence, and finally a cold isostatic press is used to press and shape the green body;

[0040] The tungsten fiber mesh is laid with a spacing of 1mm to 3mm, a wire diameter of 10μm to 50μm, and a mesh size of 10 to 100 meshes; a cold isostatic press is used, and the pressure is maintained at 150MPa to 300MPa for 30min to 90min;

[0041] Step 4, placing the green body in a hydrogen sintering furnace for skeleton forming and sintering;

[0042] Step 4 is as follows:

[0043] Pressed green body sintering: The sintering method is to place the fine-grained tungsten-rhenium alloy powder at the bottom and the coarse-grained tungsten-rhenium alloy powder at the top vertically, using a medium-frequency sintering furnace in a hydrogen atmosphere, with a temperature rise stage of 600℃~1000℃ for 1h~4h, and a temperature hold stage of 1800℃~2300℃ for 6h~12h, in order to further reduce the rhenium oxide in the coating layer;

[0044] Step 5, placing the copper infiltrated with the gradient surface of the sintered blank parallel to the bottom of the graphite boat, and reserving the thickness of the pure copper layer in the length direction of the graphite boat to ensure that the length of the graphite boat is the height of the gradient layer of the sintered blank plus the thickness of the dense copper layer;

[0045] Step 5 is as follows:

[0046] Sintered billet infiltration, such as Figure 1 As shown: the size of the graphite boat is designed according to the size of the sintered blank. During the melt infiltration, the inner length L of the graphite boat needs to be determined in combination with the height h of the sintered blank to ensure that the coarse-grained sintered end of the sintered blank obtains a pure copper layer of designed thickness after the melt infiltration is completed. The inner width W of the graphite boat needs to be determined in combination with the length l of the sintered blank, and the inner height H of the graphite boat needs to be determined in combination with the width w of the sintered blank. The buried infiltration method is used for copper infiltration treatment, and the amount of copper used is the volume of the graphite boat minus the volume of the sintered blank, that is, the required copper volume. The sintering temperature of the melt infiltration furnace is 1100℃~1500℃, and the heat preservation is 4h~8h.

[0047] Before sintering, Figure 1As shown, a tungsten-rhenium alloy layer 1, a porous tungsten-rhenium skeleton a2 and a porous tungsten-rhenium skeleton b are sequentially arranged in the graphite boat, and a pure copper layer space 4 is reserved on one side of the porous tungsten-rhenium skeleton b; wherein the tungsten-rhenium alloy layer 1 is sintered from fine-grained tungsten-rhenium alloy powder, the porous tungsten-rhenium skeleton a2 is sintered from medium-grained tungsten-rhenium alloy powder, and the porous tungsten-rhenium skeleton b3 is sintered from coarse-grained tungsten-rhenium alloy powder;

[0048] Step 6, mechanically processing the infiltrated blank to obtain a four-layer tungsten-rhenium copper-infiltrated gradient material including a tungsten-rhenium alloy layer 1, a tungsten-rhenium-low copper layer 5, a tungsten-rhenium-high copper layer 6 and a pure copper layer 7.

[0049] Step 6, shaping treatment: After the infiltration is completed, the sintered blank is machined to remove the excess copper on the outside of the sintered blank, retain the coarse-grained pure copper layer at the sintered end, and obtain a four-gradient tungsten-rhenium infiltrated copper gradient material, which is a tungsten-rhenium alloy layer, a tungsten-rhenium-less copper layer, a tungsten-rhenium-more copper layer and a pure copper layer. Figure 2 shown.

[0050] Through the above manner, the tungsten-rhenium-copper-infiltrated gradient material and the preparation method thereof of the present invention, the tungsten-rhenium-copper layer in the middle of the gradient material, the copper content is flexible and variable, and the particle size of the tungsten powder can be adjusted according to actual needs (the particle sizes of the three types of tungsten powders, namely fine particle size, medium particle size and coarse particle size, are all in the micron level); the tungsten-rhenium alloy has higher high-temperature strength and plasma etching resistance than pure tungsten; the tungsten fiber mesh gives full play to the excellent properties of the fiber itself to improve the toughness of the material; the sintering process obtains a dense pure tungsten-rhenium alloy layer, and at the same time obtains a tungsten-rhenium alloy skeleton with the required porosity, and during the infiltration process, copper fills the pores inside the skeleton, and a high-strength combination of pure tungsten-rhenium alloy and tungsten-rhenium copper, and a high-strength combination of tungsten-rhenium copper and pure copper are obtained at one time, avoiding the existing material to achieve the combination of pure tungsten and tungsten-copper transition layer, and the combination of tungsten-copper transition layer and pure copper by two hot isostatic pressing methods respectively, which is beneficial to solving the actual needs of materials for thermonuclear fusion plasma-oriented components.

[0051] The present invention also provides a tungsten-rhenium copper-infiltrated gradient material, comprising a tungsten-rhenium alloy layer, a tungsten-rhenium-less copper layer, a tungsten-rhenium-more copper layer and a pure copper layer arranged in sequence, and is prepared by the above method.

[0052] Example 1

[0053] A W-3Re / Cu gradient material with specifications of w: 500mm, h: 400mm, and l: 500mm was prepared, wherein the thickness of each gradient layer was 100mm, and the Cu content of the Cu-less layer was 5wt%, corresponding to a relative density of 86% of the standard sintered skeleton, and the Cu content of the Cu-rich layer was 10wt%, corresponding to a relative density of 80% of the standard sintered skeleton.

[0054] Step 1, select three types of W powder: Fss1μm, Fss5μm, and Fss8μm;

[0055] Step 2, W-3Re layer W powder particle size is Fss1μm, dense W-3Re density is 19.37g / cm 3 , the mass of W-3Re required for a height of 100mm is (100mm×500mm×500mm)×

[0056] 19.37g / cm 3 =484250g, of which the mass of W powder is 484250×97%=469722.5g, the mass of Re powder is 484250×3%=14527.5g, and the bulk density of W powder Fss1μm is 4.8g / cm 3 The required tungsten powder volume is 469722.5g / 4.8g / cm 3 =97858.85cm 3 , the volume of 3N purity NH4ReO4 solution is 3 times the volume of the required tungsten powder, which is 97858.85×3=392576.55ml, the mass of Re in NH4ReO4 is 69.4wt%, and the mass of NH4ReO4 required is 14527.5g / 69.4%=20932.99g; a constant temperature water bath is used to prepare NH4ReO4 solution with deionized water as solvent, W powder is placed in ammonium perrhenate solution, stirred at a constant temperature of 70℃, and after complete volatilization, NH4ReO4 coated W powder is obtained; NH4ReO4 coated W powder is dried in a drying oven at 150℃ for 6h, and the dried powder is crushed by ball milling for 3h, ball milling ratio is 2:1, and rotation speed is 120r / min to obtain uniformly dispersed tungsten-rhenium alloy powder;

[0057] The particle size of W powder in W-3Re-5Cu layer is Fss5μm, and the density of dense W-3Re is 19.37g / cm 3 , the relative density of the skeleton is 86%, and the skeleton density of W-3Re is 19.37g / cm 3 ×86%=16.65g / cm 3 , the mass of W-3Re required for a height of 100mm is (100mm×500mm×500mm)×

[0058] 16.65g / cm 3 =416455g, of which the mass of W powder is 416455×97%=403961.35g, the mass of Re powder is 416455×3%=12493.65g, and the bulk density of W powder Fss5μm is 6.3g / cm 3 The required tungsten powder volume is 403961.35 / 6.3g / cm 3 =64120.84cm 3, the volume of 3N purity NH4ReO4 solution is 3 times the volume of the required tungsten powder, which is 64120.84×3=192362.52ml, the mass of Re in NH4ReO4 is 69.4wt%, and the mass of NH4ReO4 required is 12493.65g / 69.4%=18002.37g; a constant temperature water bath is used to prepare NH4ReO4 solution with deionized water as solvent, W powder is placed in ammonium perrhenate solution, stirred at a constant temperature of 70℃, and after complete volatilization, NH4ReO4 coated W powder is obtained; NH4ReO4 coated W powder is dried in a drying oven at 150℃ for 6h, and the dried powder is crushed by ball milling for 3h, ball milling ratio is 2:1, and rotation speed is 120r / min to obtain uniformly dispersed tungsten-rhenium alloy powder;

[0059] The particle size of W powder in W-3Re-10Cu layer is Fss8μm, and the density of dense W-3Re is 19.37g / cm 3 , the relative density of the skeleton is 80%, and the skeleton density of W-3Re is 19.37g / cm 3 ×80%=15.49g / cm 3 , the mass of W-3Re required for a height of 100mm is (100mm×500mm×500mm)×

[0060] 15.49g / cm 3 =387250g, of which the mass of W powder is 387250×97%=375632.5g, the mass of Re powder is 387250×3%=11617.5g, and the bulk density of W powder Fss8μm is 8.6g / cm 3 The required tungsten powder volume is 375632.5g / 8.6g / cm 3 =43678.19cm 3 , the volume of 3N purity NH4ReO4 solution is 3 times the volume of the required tungsten powder, which is 43678.19×3=131034.57ml, the mass of Re in NH4ReO4 is 69.4wt%, and the mass of NH4ReO4 required is 11617.5g / 69.4%=16739.91g; a constant temperature water bath is used to prepare NH4ReO4 solution with deionized water as solvent, W powder is placed in ammonium perrhenate solution, stirred at a constant temperature of 70℃, and after complete volatilization, NH4ReO4 coated W powder is obtained; NH4ReO4 coated W powder is dried in a drying oven at 150℃ for 6h, and the dried powder is crushed by ball milling for 3h, with a ball-to-material ratio of 2:1 and a rotation speed of 120r / min to obtain a uniformly dispersed tungsten-rhenium alloy powder;

[0061] Step 3, the three kinds of tungsten-rhenium alloy powders and the tungsten fiber mesh obtained in step 2 are sequentially loaded into the molding rubber sleeve according to the particle size level from small to large, and pressed by a cold isostatic press to obtain a green body;

[0062] Step 3 is as follows:

[0063] The fine-grained tungsten-rhenium alloy powder is first laid on the bottom layer of the molding rubber sleeve with a laying thickness of 3mm, and then a layer of tungsten fiber mesh is laid, and then a layer of tungsten fiber mesh is added at a height of 1mm for each powder laying. After the fine-grained tungsten-rhenium alloy powder is laid, a layer of tungsten fiber mesh is still added at a height of 1mm for each powder laying, and then medium-grained tungsten-rhenium alloy powder and coarse-grained tungsten-rhenium alloy powder are laid in sequence, and finally a cold isostatic press is used to press and shape the green body;

[0064] The tungsten fiber mesh has a laying interval of 1mm, a wire diameter of 10μm, and a mesh size of 10. A cold isostatic press is used to maintain the pressure at 150MPa for 60min.

[0065] Step 4, placing the green body in a hydrogen sintering furnace for skeleton forming and sintering;

[0066] Step 4 is as follows:

[0067] Pressed green body sintering: The sintering method is to place the fine-grained tungsten-rhenium alloy powder at the bottom and the coarse-grained tungsten-rhenium alloy powder at the top vertically, using a medium-frequency sintering furnace in a hydrogen atmosphere, keeping the temperature at 620°C for 2 hours in the heating stage and 1900°C for 9 hours in the insulation stage to complete the further reduction of the rhenium oxide in the coating layer;

[0068] Step 5, placing the copper infiltrated with the gradient surface of the sintered blank parallel to the bottom of the graphite boat, and reserving the thickness of the pure copper layer in the length direction of the graphite boat to ensure that the length of the graphite boat is the height of the gradient layer of the sintered blank plus the thickness of the dense copper layer;

[0069] Step 5 is as follows:

[0070] Sintered billet infiltration, such as Figure 1 As shown: the size of the graphite boat is designed according to the size of the sintered blank. During the melt infiltration, the inner length L of the graphite boat needs to be determined in combination with the height h of the sintered blank to ensure that the coarse-grained sintered end of the sintered blank obtains a pure copper layer of designed thickness after the melt infiltration is completed. The inner width W of the graphite boat needs to be determined in combination with the length l of the sintered blank, and the inner height H of the graphite boat needs to be determined in combination with the width w of the sintered blank. The buried infiltration method is used for copper infiltration treatment, and the amount of copper used is the volume of the graphite boat minus the volume of the sintered blank, that is, the required copper volume. The sintering temperature of the melt infiltration furnace is 1100°C, and the heat preservation is 6h.

[0071] Step 6, machining the infiltrated blank to obtain four layers of tungsten-rhenium-copper infiltrated gradient materials, namely, W-3Re layer, W-3Re-5Cu layer, W-3Re-10Cu layer and pure Cu layer.

[0072] Step 6, shaping treatment: After the infiltration is completed, the sintered blank is machined to remove the excess copper on the outside of the sintered blank, retain the coarse-grained pure copper layer at the sintered end, and obtain a four-gradient tungsten-rhenium infiltrated copper gradient material, which is a tungsten-rhenium alloy layer, a tungsten-rhenium-less copper layer, a tungsten-rhenium-more copper layer and a pure copper layer. Figure 2 shown.

[0073] The interface bonding strength of the four-layer tungsten-rhenium-copper gradient material prepared in Example 1, namely, the W-3Re layer, the W-3Re-5Cu layer, the W-3Re-10Cu layer and the pure Cu layer, is compared with that of the W layer and the Cu layer prepared by hot isostatic pressing, as shown in the following table:

[0074]

[0075] Example 2

[0076] A W-5Re / Cu gradient material with specifications of w: 300mm, h: 800mm, and l: 300mm was prepared, wherein the thickness of each gradient layer was 200mm, and the Cu content of the Cu-less layer was 7wt%, corresponding to a standard sintered skeleton relative density of 84%, and the Cu content of the Cu-rich layer was 11wt%, corresponding to a standard sintered skeleton relative density of 78%.

[0077] Step 1, select three kinds of W powder: Fss2μm, Fss6μm, and Fss9μm;

[0078] Step 2, W-5Re layer W powder particle size is Fss2μm, dense W-5Re density is 19.41g / cm 3 , the mass of W-5Re required for a height of 200mm is (200mm×300mm×300mm)×

[0079] 19.41g / cm 3 =349380g, of which the mass of W powder is 349380×95%=331911g, the mass of Re powder is 349380×5%=17469g, and the bulk density of W powder Fss2μm is 5.4g / cm 3 The required tungsten powder volume is 331911g / 5.4g / cm 3 =61465cm 3, the volume of 3N purity NH4ReO4 solution is 3 times the volume of the required tungsten powder, which is 61465×3=184395ml, the mass of Re in NH4ReO4 is 69.4wt%, and the mass of NH4ReO4 required is 17469g / 69.4%=25171.46g; a constant temperature water bath is used to prepare NH4ReO4 solution with deionized water as solvent, W powder is placed in ammonium perrhenate solution, stirred at a constant temperature of 80℃, and after complete volatilization, NH4ReO4 coated W powder is obtained; NH4ReO4 coated W powder is dried in a drying oven at 180℃ for 8h, and the dried powder is crushed by ball milling for 4h, with a ball-to-material ratio of 2:1 and a rotation speed of 130r / min to obtain a uniformly dispersed tungsten-rhenium alloy powder;

[0080] The particle size of W powder in W-5Re-7Cu layer is Fss6μm, and the density of dense W-5Re is 19.41g / cm 3 , the relative density of the skeleton is 84%, and the skeleton density of W-5Re is 19.41g / cm 3 ×84%=16.30g / cm 3 , the mass of W-5Re required for a height of 200mm is (200mm×300mm×300mm)×

[0081] 16.30g / cm 3 =293400g, of which W powder mass is 293400×95%=278730g, Re powder mass is 293400×5%=14670g, W powder Fss6μm bulk density is 8.1g / cm 3 The required tungsten powder volume is 278730 / 8.1g / cm 3 =34411.11cm 3 , the volume of 3N purity NH4ReO4 solution is 3 times the volume of the required tungsten powder, which is 34411.11×3=103233.33ml, the mass of Re in NH4ReO4 is 69.4wt%, and the mass of NH4ReO4 required is 14670g / 69.4%=21138.32g; a constant temperature water bath is used to prepare NH4ReO4 solution with deionized water as solvent, W powder is placed in ammonium perrhenate solution, stirred at a constant temperature of 80℃, and after complete volatilization, NH4ReO4 coated W powder is obtained; NH4ReO4 coated W powder is dried in a drying oven at 180℃ for 8h, and the dried powder is crushed by ball milling, ball milling for 4h, ball-to-material ratio of 2:1, and rotation speed of 130r / min to obtain a uniformly dispersed tungsten-rhenium alloy powder;

[0082] The particle size of W powder in W-5Re-11Cu layer is Fss9μm, and the density of dense W-5Re is 19.41g / cm 3, the relative density of the skeleton is 78%, and the skeleton density of W-5Re is 19.41g / cm 3 ×78%=15.13g / cm 3 , the mass of W-5Re required for a height of 200mm is (200mm×300mm×300mm)×

[0083] 15.13g / cm 3 =272340g, of which the mass of W powder is 272340×95%=258723g, the mass of Re powder is 272340×5%=13617g, and the bulk density of W powder Fss9μm is 8.9g / cm 3 The required tungsten powder volume is 258723g / 8.9g / cm 3 =29070cm 3 , the volume of 3N purity NH4ReO4 solution is 3 times the volume of the required tungsten powder, which is 29070×3=87210ml, the mass of Re in NH4ReO4 is 69.4wt%, and the mass of NH4ReO4 required is 13617g / 69.4%=19621.03g; a constant temperature water bath is used to prepare NH4ReO4 solution with deionized water as solvent, W powder is placed in ammonium perrhenate solution, stirred at a constant temperature of 80℃, and after complete volatilization, NH4ReO4 coated W powder is obtained; NH4ReO4 coated W powder is dried in a drying oven at 180℃ for 8h, and the dried powder is crushed by ball milling for 4h, with a ball-to-material ratio of 2:1 and a rotation speed of 130r / min to obtain a uniformly dispersed tungsten-rhenium alloy powder;

[0084] Step 3, the three kinds of tungsten-rhenium alloy powders and the tungsten fiber mesh obtained in step 2 are sequentially loaded into the molding rubber sleeve according to the particle size level from small to large, and pressed by a cold isostatic press to obtain a green body;

[0085] Step 3 is as follows:

[0086] The fine-grained tungsten-rhenium alloy powder is first laid on the bottom layer of the molding rubber sleeve with a laying thickness of 5mm, and then a layer of tungsten fiber mesh is laid, and then a layer of tungsten fiber mesh is added at a height of 2mm for each powder laying. After the fine-grained tungsten-rhenium alloy powder is laid, a layer of tungsten fiber mesh is still added at a height of 2mm for each powder laying, and then medium-grained tungsten-rhenium alloy powder and coarse-grained tungsten-rhenium alloy powder are laid in sequence, and finally a cold isostatic press is used to press and shape the green body;

[0087] Among them, the laying spacing of the tungsten fiber mesh is 2mm, the wire diameter of the tungsten fiber mesh is 25μm, and the mesh number is 30 meshes; a cold isostatic press is used, and the pressure is maintained at 200MPa for 30min;

[0088] Step 4, placing the green body in a hydrogen sintering furnace for skeleton forming and sintering;

[0089] Step 4 is as follows:

[0090] Pressed green body sintering: The sintering method is to place the fine-grained tungsten-rhenium alloy powder at the bottom and the coarse-grained tungsten-rhenium alloy powder at the top vertically, using a medium-frequency sintering furnace in a hydrogen atmosphere, keeping the temperature at 740°C for 3 hours in the heating stage and at 2000°C for 10 hours in the insulation stage, in order to further reduce the rhenium oxide in the coating layer;

[0091] Step 5, placing the copper infiltrated with the gradient surface of the sintered blank parallel to the bottom of the graphite boat, and reserving the thickness of the pure copper layer in the length direction of the graphite boat to ensure that the length of the graphite boat is the height of the gradient layer of the sintered blank plus the thickness of the dense copper layer;

[0092] Step 5 is as follows:

[0093] Sintered billet infiltration, such as Figure 1 As shown: the size of the graphite boat is designed according to the size of the sintered blank. During the melt infiltration, the inner length L of the graphite boat needs to be determined in combination with the height h of the sintered blank to ensure that the coarse-grained sintered end of the sintered blank obtains a pure copper layer of designed thickness after the melt infiltration is completed. The inner width W of the graphite boat needs to be determined in combination with the length l of the sintered blank, and the inner height H of the graphite boat needs to be determined in combination with the width w of the sintered blank. The buried infiltration method is used for copper infiltration treatment, and the amount of copper used is the volume of the graphite boat minus the volume of the sintered blank, that is, the required copper volume. The sintering temperature of the melt infiltration furnace is 1200℃, and the heat preservation is 6h.

[0094] Step 6, machining the infiltrated blank to obtain four layers of tungsten-rhenium-copper infiltrated gradient materials, namely, W-5Re layer, W-5Re-7Cu layer, W-5Re-11Cu layer and pure Cu layer.

[0095] Step 6, shaping treatment: After the infiltration is completed, the sintered blank is machined to remove the excess copper on the outside of the sintered blank, retain the coarse-grained pure copper layer at the sintered end, and obtain a four-gradient tungsten-rhenium infiltrated copper gradient material, which is a tungsten-rhenium alloy layer, a tungsten-rhenium-less copper layer, a tungsten-rhenium-more copper layer and a pure copper layer. Figure 2 shown.

[0096] The interface bonding strength of the four-layer tungsten-rhenium-copper gradient material prepared in Example 2, namely, the W-5Re layer, the W-5Re-7Cu layer, the W-5Re-11Cu layer and the pure Cu layer, is compared with that of the W layer and the Cu layer prepared by hot isostatic pressing, as shown in the following table:

[0097]

[0098] Example 3

[0099] A W-8Re / Cu gradient material with specifications of w: 200mm, h: 600mm, and l: 300mm was prepared, wherein the thickness of each gradient layer was 150mm, and the Cu content of the Cu-less layer was 5wt%, corresponding to a standard sintered skeleton relative density of 86%, and the Cu content of the Cu-rich layer was 7wt%, corresponding to a standard sintered skeleton relative density of 84%.

[0100] Step 1, select three kinds of W powder: Fss3μm, Fss8μm, and Fss12μm;

[0101] Step 2, W-8Re layer W powder particle size is Fss3μm, dense W-8Re density is 19.45g / cm 3 , the mass of W-8Re required for 150mm height is (150mm×200mm×300mm)×

[0102] 19.45g / cm 3 =175050g, of which the mass of W powder is 175050×92%=161046g, the mass of Re powder is 175050×8%=14004g, and the bulk density of W powder Fss3μm is 5.8g / cm 3 The required tungsten powder volume is 161046g / 5.8g / cm 3 =27766.55cm 3 , the volume of 3N purity NH4ReO4 solution is 3 times the volume of the required tungsten powder, which is 27766.55×3=83299.65ml, the mass of Re in NH4ReO4 is 69.4wt%, and the mass of NH4ReO4 required is 14004g / 69.4%=20178.67g; a constant temperature water bath is used to prepare NH4ReO4 solution with deionized water as solvent, W powder is placed in ammonium perrhenate solution, stirred at a constant temperature of 90℃, and after complete volatilization, NH4ReO4 coated W powder is obtained; NH4ReO4 coated W powder is dried in a drying oven at 300℃ for 7h, and the dried powder is crushed by ball milling, ball milling for 4h, ball-to-material ratio of 2:1, and rotation speed of 220r / min to obtain a uniformly dispersed tungsten-rhenium alloy powder;

[0103] The W powder particle size of the W-8Re-5Cu layer is Fss8μm, and the density of the dense W-8Re is 19.45g / cm 3 , the relative density of the skeleton is 86%, and the skeleton density of W-8Re is 19.45g / cm 3 ×86%=16.72g / cm 3 , the mass of W-8Re required for 150mm height is (150mm×200mm×300mm)×

[0104] 16.72g / cm 3=150480g, of which the mass of W powder is 150480×87 / (87+8)=137808g, the mass of Re powder is 150480×8 / (87+8)=12672g, and the bulk density of W powder Fss8μm is 8.6g / cm 3 The required tungsten powder volume is 137808 / 8.6g / cm 3 =16024.18cm 3 , the volume of 3N purity NH4ReO4 solution is 3 times the volume of the required tungsten powder, which is 16024.18×3=48072.54ml, the mass of Re in NH4ReO4 is 69.4wt%, and the mass of NH4ReO4 required is 12672g / 69.4%=8794.36g; a constant temperature water bath is used to prepare NH4ReO4 solution with deionized water as solvent, W powder is placed in ammonium perrhenate solution, stirred at a constant temperature of 90℃, and after complete volatilization, NH4ReO4 coated W powder is obtained; NH4ReO4 coated W powder is dried in a drying oven at 300℃ for 7h, and the dried powder is crushed by ball milling, ball milling for 4h, ball-to-material ratio of 2:1, and rotation speed of 220r / min to obtain a uniformly dispersed tungsten-rhenium alloy powder;

[0105] The particle size of W powder in W-8Re-7Cu layer is Fss12μm, and the density of dense W-8Re is 19.45g / cm 3 , the relative density of the skeleton is 84%, and the skeleton density of W-8Re is 19.45g / cm 3 ×84%=16.33g / cm 3 , the mass of W-8Re required for 150mm height is (150mm×200mm×300mm)×

[0106] 16.33g / cm 3 =146970g, of which the mass of W powder is 146970×92%=135212.4g, the mass of Re powder is 146970×8%=11757.6g, and the bulk density of W powder Fss12μm is 9.7g / cm 3 The required tungsten powder volume is 135212.4 / 9.7g / cm 3 =13939.42cm 3, the volume of 3N purity NH4ReO4 solution is 3 times the volume of the required tungsten powder, which is 13939.42×3=41818.26ml, the mass of Re in NH4ReO4 is 69.4wt%, and the mass of NH4ReO4 required is 11757.6g / 69.4%=16941.78g; a constant temperature water bath is used to prepare NH4ReO4 solution with deionized water as solvent, W powder is placed in ammonium perrhenate solution, stirred at a constant temperature of 90°C, and after complete volatilization, NH4ReO4 coated W powder is obtained; NH4ReO4 coated W powder is dried in a drying oven at 300°C for 7h, and the dried powder is crushed by ball milling, ball milling for 4h, ball-to-material ratio of 2:1, and rotation speed of 220r / min to obtain a uniformly dispersed tungsten-rhenium alloy powder;

[0107] Step 3, the three kinds of tungsten-rhenium alloy powders and the tungsten fiber mesh obtained in step 2 are sequentially loaded into the molding rubber sleeve according to the particle size level from small to large, and pressed by a cold isostatic press to obtain a green body;

[0108] Step 3 is as follows:

[0109] The fine-grained tungsten-rhenium alloy powder is first laid on the bottom layer of the molding rubber sleeve with a laying thickness of 6mm, and then a layer of tungsten fiber mesh is laid, and then a layer of tungsten fiber mesh is added at a height of 3mm for each powder laying. After the fine-grained tungsten-rhenium alloy powder is laid, a layer of tungsten fiber mesh is still added at a height of 3mm for each powder laying, and then medium-grained tungsten-rhenium alloy powder and coarse-grained tungsten-rhenium alloy powder are laid in sequence, and finally a cold isostatic press is used to press and shape the green body;

[0110] Among them, the laying spacing of the tungsten fiber mesh is 3mm, the wire diameter of the tungsten fiber mesh is 45μm, and the mesh number is 70 mesh; a cold isostatic press is used, and the pressure is maintained at 280MPa for 30min;

[0111] Step 4, placing the green body in a hydrogen sintering furnace for skeleton forming and sintering;

[0112] Step 4 is as follows:

[0113] Pressed green body sintering: The sintering method is to place the fine-grained tungsten-rhenium alloy powder at the bottom and the coarse-grained tungsten-rhenium alloy powder at the top vertically, using a medium-frequency sintering furnace in a hydrogen atmosphere, keeping the temperature at 880°C for 3.5 hours in the heating stage and at 2300°C for 11 hours in the insulation stage, in order to further reduce the rhenium oxide in the coating layer;

[0114] Step 5, placing the copper infiltrated with the gradient surface of the sintered blank parallel to the bottom of the graphite boat, and reserving the thickness of the pure copper layer in the length direction of the graphite boat to ensure that the length of the graphite boat is the height of the gradient layer of the sintered blank plus the thickness of the dense copper layer;

[0115] Step 5 is as follows:

[0116] Sintered billet infiltration, such as Figure 1As shown: the size of the graphite boat is designed according to the size of the sintered blank. During the melt infiltration, the inner length L of the graphite boat needs to be determined in combination with the height h of the sintered blank to ensure that the coarse-grained sintered end of the sintered blank obtains a pure copper layer of designed thickness after the melt infiltration is completed. The inner width W of the graphite boat needs to be determined in combination with the length l of the sintered blank, and the inner height H of the graphite boat needs to be determined in combination with the width w of the sintered blank. The buried infiltration method is used for copper infiltration treatment, and the amount of copper used is the volume of the graphite boat minus the volume of the sintered blank, that is, the required copper volume. The sintering temperature of the melt infiltration furnace is 1400℃, and the heat preservation is 7h.

[0117] Step 6, machining the infiltrated blank to obtain four layers of tungsten-rhenium-copper infiltrated gradient materials, namely, W-8Re layer, W-8Re-5Cu layer, W-8Re-7Cu layer and pure Cu layer.

[0118] Step 6, shaping treatment: After the infiltration is completed, the sintered blank is machined to remove the excess copper on the outside of the sintered blank, retain the coarse-grained pure copper layer at the sintered end, and obtain a four-gradient tungsten-rhenium infiltrated copper gradient material, which is a tungsten-rhenium alloy layer, a tungsten-rhenium-less copper layer, a tungsten-rhenium-more copper layer and a pure copper layer. Figure 2 shown.

[0119] The interface bonding strength of the four-layer tungsten-rhenium-copper-infiltrated gradient material of W-8Re layer, W-8Re-5Cu layer, W-8Re-7Cu layer and pure Cu layer prepared in Example 3 is compared with that of the W layer and Cu layer prepared by hot isostatic pressing, as shown in the following table:

[0120]

[0121] Example 4

[0122] A W-6Re / Cu gradient material with specifications of w: 100mm, h: 400mm, and l: 200mm was prepared, wherein the thickness of each gradient layer was 150mm, and the Cu content of the Cu-less layer was 5wt%, corresponding to a relative density of 86% of the standard sintered skeleton, and the Cu content of the Cu-rich layer was 13wt%, corresponding to a relative density of 76% of the standard sintered skeleton.

[0123] Step 1, select three types of W powder: Fss2μm, Fss5μm, and Fss12μm;

[0124] Step 2, W-6Re layer W powder particle size is Fss3μm, dense W-6Re density is 19.41g / cm 3 , the mass of W-6Re required for a height of 100mm is (100mm×100mm×200mm)×

[0125] 19.41g / cm 3=38820g, of which the mass of W powder is 38820×94%=36490.8g, the mass of Re powder is 38820×6%=2329.2g, and the bulk density of W powder Fss2μm is 5.4g / cm 3 The required tungsten powder volume is 36490.8g / 5.4g / cm 3 =6757.55cm 3 , the volume of 4N purity NH4ReO4 solution is 3 times the volume of the required tungsten powder, which is 6757.55×3=20272.65ml, the mass of Re in NH4ReO4 is 69.4wt%, and the mass of NH4ReO4 required is 2329.2g / 69.4%=3356.19g; a constant temperature water bath is used to prepare NH4ReO4 solution with deionized water as solvent, W powder is placed in ammonium perrhenate solution, stirred at a constant temperature of 80℃, and after complete volatilization, NH4ReO4 coated W powder is obtained; NH4ReO4 coated W powder is dried in a drying oven at 250℃ for 8h, and the dried powder is crushed by ball milling, ball milling for 5h, ball-to-material ratio is 2:1, and rotation speed is 260r / min to obtain uniformly dispersed tungsten-rhenium alloy powder;

[0126] The particle size of W powder in W-6Re-5Cu layer is Fss5μm, and the density of dense W-6Re is 19.41g / cm 3 , the relative density of the skeleton is 86%, and the skeleton density of W-8Re is 19.41g / cm 3 ×86%=16.69g / cm 3 , the mass of W-6Re required for a height of 100mm is (100mm×100mm×200mm)×

[0127] 16.69g / cm 3 =33380g, of which the mass of W powder is 33380×94%=31377.2g, the mass of Re powder is 33380×4%=1335.2g, and the bulk density of W powder Fss5μm is 6.3g / cm 3 The required tungsten powder volume is 31377.2 / 6.3g / cm 3 =4980.50cm 3, the volume of 4N purity NH4ReO4 solution is 3 times the volume of the required tungsten powder, which is 4980.50×3=14941.5ml, the mass of Re in NH4ReO4 is 69.4wt%, and the mass of NH4ReO4 required is 1335.2g / 69.4%=1923.91g; a constant temperature water bath is used to prepare NH4ReO4 solution with deionized water as solvent, W powder is placed in ammonium perrhenate solution, stirred at a constant temperature of 80℃, and after complete volatilization, NH4ReO4 coated W powder is obtained; NH4ReO4 coated W powder is dried in a drying oven at 250℃ for 8h, and the dried powder is crushed by ball milling, ball milling for 5h, ball-to-material ratio of 2:1, and rotation speed of 260r / min to obtain a uniformly dispersed tungsten-rhenium alloy powder;

[0128] The particle size of W powder in W-6Re-13Cu layer is Fss12μm, and the density of dense W-6Re is 19.41g / cm 3 The relative density of the skeleton is 76%, and the skeleton density of W-6Re is 19.41g / cm 3 ×76%=14.75g / cm 3 , the mass of W-6Re required for a height of 100mm is (100mm×100mm×200mm)×

[0129] 14.75g / cm 3 =29500g, of which W powder mass is 29500×94%=27730g, Re powder mass is 29500×6%=1770g, W powder Fss12μm bulk density is 9.7g / cm 3 The required tungsten powder volume is 27730 / 9.7g / cm 3 =2858.76cm 3 , the volume of 4N purity NH4ReO4 solution is 3 times the volume of the required tungsten powder, which is 2858.76×3=8576.28ml, the mass of Re in NH4ReO4 is 69.4wt%, and the mass of NH4ReO4 required is 1770g / 69.4%=2550.43g; a constant temperature water bath is used to prepare NH4ReO4 solution with deionized water as solvent, W powder is placed in ammonium perrhenate solution, stirred at a constant temperature of 80℃, and after complete volatilization, NH4ReO4 coated W powder is obtained; NH4ReO4 coated W powder is dried in a drying oven at 250℃ for 8h, and the dried powder is crushed by ball milling, ball milling for 5h, ball-to-material ratio of 2:1, and rotation speed of 260r / min to obtain a uniformly dispersed tungsten-rhenium alloy powder;

[0130] Step 3, the three kinds of tungsten-rhenium alloy powders and the tungsten fiber mesh obtained in step 2 are sequentially loaded into the molding rubber sleeve according to the particle size level from small to large, and pressed by a cold isostatic press to obtain a green body;

[0131] Step 3 is as follows:

[0132] The fine-grained tungsten-rhenium alloy powder is first laid on the bottom layer of the molding rubber sleeve with a laying thickness of 4mm, and then a layer of tungsten fiber mesh is laid, and then a layer of tungsten fiber mesh is added at a height of 2mm for each powder laying. After the fine-grained tungsten-rhenium alloy powder is laid, a layer of tungsten fiber mesh is still added at a height of 2mm for each powder laying, and then medium-grained tungsten-rhenium alloy powder and coarse-grained tungsten-rhenium alloy powder are laid in sequence, and finally a cold isostatic press is used to press and shape the green body;

[0133] Among them, the laying spacing of the tungsten fiber mesh is 2mm, the wire diameter of the tungsten fiber mesh is 30μm, and the mesh number is 80 mesh; a cold isostatic press is used, and the pressure is maintained at 270MPa for 65min;

[0134] Step 4, placing the green body in a hydrogen sintering furnace for skeleton forming and sintering;

[0135] Step 4 is as follows:

[0136] Pressed green body sintering: The sintering method is to place the fine-grained tungsten-rhenium alloy powder at the bottom and the coarse-grained tungsten-rhenium alloy powder at the top vertically, using a medium-frequency sintering furnace in a hydrogen atmosphere, keeping the temperature at 920°C for 1.8 hours in the heating stage and at 2000°C for 10 hours in the insulation stage, in order to further reduce the rhenium oxide in the coating layer;

[0137] Step 5, placing the copper infiltrated with the gradient surface of the sintered blank parallel to the bottom of the graphite boat, and reserving the thickness of the pure copper layer in the length direction of the graphite boat to ensure that the length of the graphite boat is the height of the gradient layer of the sintered blank plus the thickness of the dense copper layer;

[0138] Step 5 is as follows:

[0139] Sintered billet infiltration, such as Figure 1 As shown: the size of the graphite boat is designed according to the size of the sintered blank. During the melt infiltration, the inner length L of the graphite boat needs to be determined in combination with the height h of the sintered blank to ensure that the coarse-grained sintered end of the sintered blank obtains a pure copper layer of designed thickness after the melt infiltration is completed. The inner width W of the graphite boat needs to be determined in combination with the length l of the sintered blank, and the inner height H of the graphite boat needs to be determined in combination with the width w of the sintered blank. The buried infiltration method is used for copper infiltration treatment, and the amount of copper used is the volume of the graphite boat minus the volume of the sintered blank, that is, the required copper volume. The sintering temperature of the melt infiltration furnace is 1200℃, and the heat preservation is 6h.

[0140] Step 6: Machining the infiltrated blank to obtain a four-layer tungsten-rhenium copper-infiltrated gradient material, which is a W-6Re layer, a W-6Re-5Cu layer, a W-6Re-13Cu layer and a pure Cu layer. Step 6: Shaping: Machining the sintered blank after infiltration to remove excess copper on the outside of the sintered blank, retaining the coarse-grained pure copper layer at the sintered end, to obtain a four-layer tungsten-rhenium copper-infiltrated gradient material, which is a tungsten-rhenium alloy layer, a tungsten-rhenium-less copper layer, a tungsten-rhenium-more copper layer and a pure copper layer, such as Figure 2The interface bonding strength of the four-layer tungsten-rhenium-copper gradient material prepared in Example 4, including the W-6Re layer, the W-6Re-5Cu layer, the W-6Re-13Cu layer and the pure Cu layer, is compared with that of the W layer and the Cu layer prepared by hot isostatic pressing, as shown in the following table:

[0141]

[0142] Example 5

[0143] A W-2Re / Cu gradient material with specifications of w: 500mm, h: 320mm, and l: 500mm was prepared, wherein the thickness of each gradient layer was 150mm, and the Cu content of the Cu-less layer was 8wt%, corresponding to a relative density of 83% of the standard sintered skeleton, and the Cu content of the Cu-rich layer was 15wt%, corresponding to a relative density of 76% of the standard sintered skeleton.

[0144] Step 1, select three types of W powder: Fss1μm, Fss4μm, and Fss8μm;

[0145] Step 2, W-2Re layer W powder particle size is Fss1μm, dense W-2Re density is 19.37g / cm 3 , the W-2Re mass required for 80mm height is (80mm×500mm×500mm)×

[0146] 19.37g / cm 3 =387400g, of which W powder mass is 387400×98%=379652g, Re powder mass is 387400×2%=7748g, W powder Fss1μm bulk density is 4.8g / cm 3 The required tungsten powder volume is 379652g / 4.8g / cm 3 =79094.16cm 3 , the volume of 5N purity NH4ReO4 solution is 3 times the volume of the required tungsten powder, which is 79094.16×3=237282.48ml, the mass of Re in NH4ReO4 is 69.4wt%, and the mass of NH4ReO4 required is 7748g / 69.4%=11164.26g; a constant temperature water bath is used to prepare NH4ReO4 solution with deionized water as solvent, W powder is placed in ammonium perrhenate solution, stirred at a constant temperature of 100℃, and NH4ReO4 coated W powder is obtained after complete volatilization; NH4ReO4 coated W powder is dried in a drying oven at 400℃ for 10h, and the dried powder is crushed by ball milling for 6h, with a ball-to-material ratio of 2:1 and a rotation speed of 300r / min to obtain a uniformly dispersed tungsten-rhenium alloy powder;

[0147] The W powder particle size of the W-2Re-8Cu layer is Fss4μm, and the density of the dense W-2Re is 19.37g / cm3 , the relative density of the skeleton is 83%, and the skeleton density of W-2Re is 19.37g / cm 3 ×83%=16.07g / cm 3 , the W-2Re mass required for 80mm height is (80mm×500mm×500mm)×

[0148] 16.07g / cm 3 =321400g, of which W powder mass is 321400×98%=314972g, Re powder mass is 321400×2%=6428g, W powder Fss4μm bulk density is 6.0g / cm 3 The required tungsten powder volume is 314972 / 6.0g / cm 3 =52495.33cm 3 , the volume of 4N purity NH4ReO4 solution is 3 times the volume of the required tungsten powder, which is 52495.33×3=157485.99ml, the mass of Re in NH4ReO4 is 69.4wt%, and the mass of NH4ReO4 required is 6428g / 69.4%=9262.24g; a constant temperature water bath is used to prepare NH4ReO4 solution with deionized water as solvent, W powder is placed in ammonium perrhenate solution, stirred at a constant temperature of 100℃, and after complete volatilization, NH4ReO4 coated W powder is obtained; NH4ReO4 coated W powder is dried in a drying oven at 400℃ for 10h, and the dried powder is crushed by ball milling, ball milling for 6h, ball-to-material ratio of 2:1, and rotation speed of 300r / min to obtain a uniformly dispersed tungsten-rhenium alloy powder;

[0149] The particle size of W powder in W-2Re-13Cu layer is Fss8μm, and the density of dense W-2Re is 19.37g / cm 3 The relative density of the skeleton is 76%, and the skeleton density of W-2Re is 19.37g / cm 3 ×76%=14.72g / cm 3 , the W-2Re mass required for 80mm height is (80mm×500mm×500mm)×

[0150] 14.72g / cm 3 =294400g, of which W powder mass is 294400×98%=288512g, Re powder mass is 294400×2%=5888g, W powder Fss8μm bulk density is 8.6g / cm 3 The required tungsten powder volume is 288512 / 8.6g / cm 3 =33547.90cm 3, the volume of 4N purity NH4ReO4 solution is 3 times the volume of the required tungsten powder, which is 2858.76×3=8576.28ml, the mass of Re in NH4ReO4 is 69.4wt%, and the mass of NH4ReO4 required is 5888g / 69.4%=8484.15g; a constant temperature water bath is used to prepare NH4ReO4 solution with deionized water as solvent, W powder is placed in ammonium perrhenate solution, stirred at a constant temperature of 100℃, and after complete volatilization, NH4ReO4 coated W powder is obtained; NH4ReO4 coated W powder is dried in a drying oven at 400℃ for 10h, and the dried powder is crushed by ball milling, ball milling for 6h, ball-to-material ratio of 2:1, and rotation speed of 300r / min to obtain uniformly dispersed tungsten-rhenium alloy powder;

[0151] Step 3, the three kinds of tungsten-rhenium alloy powders and the tungsten fiber mesh obtained in step 2 are sequentially loaded into the molding rubber sleeve according to the particle size level from small to large, and pressed by a cold isostatic press to obtain a green body;

[0152] Step 3 is as follows:

[0153] The fine-grained tungsten-rhenium alloy powder is first laid on the bottom layer of the molding rubber sleeve with a thickness of 6mm, and then a layer of tungsten fiber mesh is laid, and then a layer of tungsten fiber mesh is added at a height of 2mm for each powder. After the fine-grained tungsten-rhenium alloy powder is laid, a layer of tungsten fiber mesh is still added at a height of 2mm for each powder, and then medium-grained tungsten-rhenium alloy powder and coarse-grained tungsten-rhenium alloy powder are laid in sequence, and finally a cold isostatic press is used to press and shape the green body;

[0154] The tungsten fiber mesh has a laying interval of 2 mm, a wire diameter of 50 μm, and a mesh size of 100. A cold isostatic press is used to maintain the pressure at 300 MPa for 90 minutes.

[0155] Step 4, placing the green body in a hydrogen sintering furnace for skeleton forming and sintering;

[0156] Step 4 is as follows:

[0157] Pressed green body sintering: The sintering method is to place the fine-grained tungsten-rhenium alloy powder at the bottom and the coarse-grained tungsten-rhenium alloy powder at the top vertically, using a medium-frequency sintering furnace in a hydrogen atmosphere, keeping the temperature at 1000°C for 4 hours in the heating stage and at 2300°C for 12 hours in the insulation stage, in order to further reduce the rhenium oxide in the coating layer;

[0158] Step 5, placing the copper infiltrated with the gradient surface of the sintered blank parallel to the bottom of the graphite boat, and reserving the thickness of the pure copper layer in the length direction of the graphite boat to ensure that the length of the graphite boat is the height of the gradient layer of the sintered blank plus the thickness of the dense copper layer;

[0159] Step 5 is as follows:

[0160] Sintered billet infiltration, such as Figure 1As shown: the size of the graphite boat is designed according to the size of the sintered blank. During the melt infiltration, the inner length L of the graphite boat needs to be determined in combination with the height h of the sintered blank to ensure that the coarse-grained sintered end of the sintered blank obtains a pure copper layer of designed thickness after the melt infiltration is completed. The inner width W of the graphite boat needs to be determined in combination with the length l of the sintered blank, and the inner height H of the graphite boat needs to be determined in combination with the width w of the sintered blank. The buried infiltration method is used for copper infiltration treatment. The amount of copper used is the volume of the graphite boat minus the volume of the sintered blank, which is the required copper volume. The sintering temperature of the melt infiltration furnace is 1500℃, and the heat preservation is 8h.

[0161] Step 6, machining the infiltrated blank to obtain four layers of tungsten-rhenium-copper infiltrated gradient material, namely, W-2Re layer, W-2Re-8Cu layer, W-2Re-15Cu layer and pure Cu layer.

[0162] Step 6, shaping treatment: After the infiltration is completed, the sintered blank is machined to remove the excess copper on the outside of the sintered blank, retain the coarse-grained pure copper layer at the sintered end, and obtain a four-gradient tungsten-rhenium infiltrated copper gradient material, which is a tungsten-rhenium alloy layer, a tungsten-rhenium-less copper layer, a tungsten-rhenium-more copper layer and a pure copper layer. Figure 2 shown.

[0163] The interface bonding strength of the four-layer tungsten-rhenium-copper gradient material prepared in Example 5, namely, the W-2Re layer, the W-2Re-8Cu layer, the W-2Re-15Cu layer and the pure Cu layer, is compared with that of the W layer and the Cu layer prepared by hot isostatic pressing, as shown in the following table:

[0164]

[0165] Example 6

[0166] A W-1Re / Cu gradient material with specifications of w: 100mm, h: 400mm, and l: 100mm was prepared, wherein the thickness of each gradient layer was 100mm, and the Cu content of the Cu-less layer was 6wt%, corresponding to a standard sintered skeleton relative density of 82%, and the Cu content of the Cu-rich layer was 12wt%, corresponding to a standard sintered skeleton relative density of 78%.

[0167] Step 1, select three kinds of W powder: Fss1μm, Fss8μm, and Fss12μm;

[0168] Step 2, W-1Re layer W powder particle size is Fss1μm, dense W-1Re density is 19.34g / cm 3 , the W-1Re mass required for a height of 100mm is (100mm×100mm×200mm)×

[0169] 19.34g / cm 3=38680g, of which the mass of W powder is 38680×99%=38293.2g, the mass of Re powder is 38680×1%=3868g, and the bulk density of W powder Fss1μm is 4.8g / cm 3 The required tungsten powder volume is 38293.2g / 4.8g / cm 3 =7977.5cm 3 , the volume of 4N purity NH4ReO4 solution is 3 times the volume of the required tungsten powder, which is 7977.5×3=23933.25ml, the mass of Re in NH4ReO4 is 69.4wt%, and the mass of NH4ReO4 required is 23933.25g / 69.4%=34485.95g; a constant temperature water bath is used to prepare NH4ReO4 solution with deionized water as solvent, W powder is placed in ammonium perrhenate solution, stirred at a constant temperature of 75℃, and NH4ReO4 coated W powder is obtained after complete volatilization; the NH4ReO4 coated W powder is dried in a drying oven at 180℃ for 7h, and the dried powder is crushed by ball milling for 4h, with a ball-to-material ratio of 2:1 and a rotation speed of 180r / min to obtain a uniformly dispersed tungsten-rhenium alloy powder;

[0170] The particle size of W powder in W-1Re-6Cu layer is Fss8μm, and the density of dense W-1Re is 19.34g / cm 3 , the relative density of the skeleton is 82%, and the skeleton density of W-1Re is 19.34g / cm 3 ×82%=15.85g / cm 3 , the W-1Re mass required for a height of 100mm is (100mm×100mm×200mm)×

[0171] 15.85g / cm 3 =31700g, of which the mass of W powder is 31700×99%=31383g, the mass of Re powder is 31700×1%=3170g, and the bulk density of W powder Fss5μm is 6.3g / cm 3 The required tungsten powder volume is 31383 / 6.3g / cm 3 =4981.42cm 3, the volume of 4N purity NH4ReO4 solution is 3 times the volume of the required tungsten powder, which is 4981.42×3=14944.26ml, the mass of Re in NH4ReO4 is 69.4wt%, and the mass of NH4ReO4 required is 3170g / 69.4%=4567.72g; a constant temperature water bath is used to prepare NH4ReO4 solution with deionized water as solvent, W powder is placed in ammonium perrhenate solution, stirred at a constant temperature of 75℃, and after complete volatilization, NH4ReO4 coated W powder is obtained; NH4ReO4 coated W powder is dried in a drying oven at 180℃ for 7h, and the dried powder is crushed by ball milling for 4h, with a ball-to-material ratio of 2:1 and a rotation speed of 180r / min to obtain a uniformly dispersed tungsten-rhenium alloy powder;

[0172] The W powder particle size of the W-1Re-12Cu layer is Fss12μm, and the density of the dense W-1Re is 19.34g / cm 3 , the relative density of the skeleton is 78%, and the skeleton density of W-1Re is 19.34g / cm 3 ×78%=15.08g / cm 3 , the W-1Re mass required for a height of 100mm is (100mm×100mm×200mm)×

[0173] 15.08g / cm 3 =30160g, of which the mass of W powder is 30160×99%=29858.4g, the mass of Re powder is 29858.4×1%=2985.84g, and the bulk density of W powder Fss12μm is 9.7g / cm 3 The required tungsten powder volume is 29858.4 / 9.7g / cm 3 =3078.18cm 3 , the volume of 4N purity NH4ReO4 solution is 3 times the volume of the required tungsten powder, which is 3078.18×3=9234.54ml, the mass of Re in NH4ReO4 is 69.4wt%, and the mass of NH4ReO4 required is 2985.84g / 69.4%=4302.36g; a constant temperature water bath is used to prepare NH4ReO4 solution with deionized water as solvent, W powder is placed in ammonium perrhenate solution, stirred at a constant temperature of 75℃, and after complete volatilization, NH4ReO4 coated W powder is obtained; NH4ReO4 coated W powder is dried in a drying oven at 180℃ for 7h, and the dried powder is crushed by ball milling for 4h, with a ball-to-material ratio of 2:1 and a rotation speed of 180r / min to obtain a uniformly dispersed tungsten-rhenium alloy powder;

[0174] Step 3, the three kinds of tungsten-rhenium alloy powders and the tungsten fiber mesh obtained in step 2 are sequentially loaded into the molding rubber sleeve according to the particle size level from small to large, and pressed by a cold isostatic press to obtain a green body;

[0175] Step 3 is as follows:

[0176] The fine-grained tungsten-rhenium alloy powder is first laid on the bottom layer of the molding rubber sleeve with a thickness of 5mm, and then a layer of tungsten fiber mesh is laid, and then a layer of tungsten fiber mesh is added at a height of 1mm for each powder. After the fine-grained tungsten-rhenium alloy powder is laid, a layer of tungsten fiber mesh is still added at a height of 1mm for each powder, and then medium-grained tungsten-rhenium alloy powder and coarse-grained tungsten-rhenium alloy powder are laid in sequence, and finally a cold isostatic press is used to press and shape the green body;

[0177] The tungsten fiber mesh has a laying interval of 1mm, a wire diameter of 20μm, and a mesh size of 60. A cold isostatic press is used to maintain the pressure at 190MPa for 60min.

[0178] Step 4, placing the green body in a hydrogen sintering furnace for skeleton forming and sintering;

[0179] Step 4 is as follows:

[0180] Pressed green body sintering: The sintering method is to place the fine-grained tungsten-rhenium alloy powder at the bottom and the coarse-grained tungsten-rhenium alloy powder at the top vertically, using a medium-frequency sintering furnace in a hydrogen atmosphere, keeping the temperature at 780°C for 3 hours in the heating stage and at 1900°C for 8 hours in the insulation stage, in order to further reduce the rhenium oxide in the coating layer;

[0181] Step 5, placing the copper infiltrated with the gradient surface of the sintered blank parallel to the bottom of the graphite boat, and reserving the thickness of the pure copper layer in the length direction of the graphite boat to ensure that the length of the graphite boat is the height of the gradient layer of the sintered blank plus the thickness of the dense copper layer;

[0182] Step 5 is specifically as follows: sintering the blank by infiltration, such as Figure 1 As shown: the size of the graphite boat is designed according to the size of the sintered blank. During the melt infiltration, the inner length L of the graphite boat needs to be determined in combination with the height h of the sintered blank to ensure that the coarse-grained sintered end of the sintered blank obtains a pure copper layer of designed thickness after the melt infiltration is completed. The inner width W of the graphite boat needs to be determined in combination with the length l of the sintered blank, and the inner height H of the graphite boat needs to be determined in combination with the width w of the sintered blank. The buried infiltration method is used for copper infiltration treatment. The amount of copper used is the volume of the graphite boat minus the volume of the sintered blank, which is the required copper volume. The sintering temperature of the melt infiltration furnace is 1400℃, and the heat preservation is 4h.

[0183] Step 6, machining the infiltrated blank to obtain four layers of tungsten-rhenium-copper infiltrated gradient material, namely, W-1Re layer, W-1Re-6Cu layer, W-1Re-12Cu layer and pure Cu layer.

[0184] Step 6, shaping treatment: After the infiltration is completed, the sintered blank is machined to remove the excess copper on the outside of the sintered blank, retain the coarse-grained pure copper layer at the sintered end, and obtain a four-gradient tungsten-rhenium infiltrated copper gradient material, which is a tungsten-rhenium alloy layer, a tungsten-rhenium-less copper layer, a tungsten-rhenium-more copper layer and a pure copper layer. Figure 2 shown.

[0185] The interface bonding strength of the four-layer tungsten-rhenium-copper gradient material prepared in Example 6, namely, the W-1Re layer, the W-1Re-6Cu layer, the W-1Re-12Cu layer and the pure Cu layer, is compared with that of the W layer and the Cu layer prepared by hot isostatic pressing, as shown in the following table:

[0186]

[0187] Conclusion: It can be seen from Examples 1-6 that the tungsten-rhenium-copper-infiltrated gradient material prepared by the method of the present invention solves the problems of the prior art that it cannot be prepared in one go and the low tensile strength of the tungsten-copper interface.

Claims

1. A method for preparing a tungsten-rhenium-copper-infiltrated gradient material, characterized in that: The following steps are involved: Step 1, selecting tungsten powders of three particle size ranges; Step 2, respectively mixing the tungsten powders of different particle size ranges selected in step 1 with the ammonium perrhenate solution to prepare three types of tungsten-rhenium alloy powders; Step 3, the three kinds of tungsten-rhenium alloy powders and the tungsten fiber mesh obtained in step 2 are sequentially loaded into the molding rubber sleeve according to the particle size level from small to large, and pressed by a cold isostatic press to obtain a green body; Step 4, placing the green body in a hydrogen sintering furnace for skeleton forming and sintering; Step 5, placing the copper infiltrated with the gradient surface of the sintered blank parallel to the bottom of the graphite boat, and reserving the thickness of the pure copper layer in the length direction of the graphite boat to ensure that the length of the graphite boat is the height of the gradient layer of the sintered blank plus the thickness of the dense copper layer; Step 6, mechanically processing the infiltrated blank to obtain four layers of tungsten-rhenium copper-infiltrated gradient material, namely, a tungsten-rhenium alloy layer, a tungsten-rhenium-low copper layer, a tungsten-rhenium-high copper layer and a pure copper layer.

2. The method for preparing the tungsten-rhenium-copper-infiltrated gradient material according to claim 1, characterized in that: In step 1, the three particle size ranges of tungsten powder are respectively: fine particle size 1-3 μm, medium particle size 3-8 μm, and coarse particle size 6-12 μm.

3. The method for preparing the tungsten-rhenium-copper-infiltrated gradient material according to claim 1, characterized in that: Step 2 is specifically as follows: Preparation of tungsten-rhenium alloy powder: selecting ammonium perrhenate with a purity of 3-5N, using a constant temperature water bath, using deionized water as a solvent and ammonium perrhenate as a solute, placing tungsten powder in an ammonium perrhenate solution according to the required tungsten: rhenium weight ratio of 92-99:8-1, wherein the volume of the solvent is 1-5 times the volume of the tungsten powder; stirring at a constant temperature of 60°C to 100°C, and after complete volatilization, obtaining ammonium perrhenate-coated tungsten powder; drying the ammonium perrhenate-coated powder in a drying oven at 100°C to 400°C for 6h to 10h, and the dried powder is crushed by ball milling for 3h to 6h, with a ball-to-material ratio of 2:1 and a rotation speed of 100r / min to 300r / min, to obtain a uniformly dispersed tungsten-rhenium alloy powder; The tungsten powder placed in the ammonium perrhenate solution is fine-grained tungsten powder, medium-grained tungsten powder or coarse-grained tungsten powder; the three tungsten powders are prepared respectively by the same tungsten-rhenium alloy powder preparation method mentioned above.

4. The method for preparing the tungsten-rhenium-copper-infiltrated gradient material according to claim 1, characterized in that: Step 3 is specifically as follows: firstly lay the fine-grained tungsten-rhenium alloy powder on the bottom layer of the molding rubber sleeve with a thickness of 3mm to 6mm, then lay a layer of tungsten fiber mesh, and then add a layer of tungsten fiber mesh at a height of 1mm to 3mm for each powder, and after laying the fine-grained tungsten-rhenium alloy powder, still add a layer of tungsten fiber mesh at a height of 1mm to 3mm for each powder, and then lay the medium-grained tungsten-rhenium alloy powder and the coarse-grained tungsten-rhenium alloy powder in turn, and finally use a cold isostatic press to press and shape to obtain a green body; Among them, the laying spacing of the tungsten fiber mesh is 1mm~3mm, the wire diameter of the tungsten fiber mesh is 10μm~50μm, and the mesh number is 10 mesh~100 mesh; a cold isostatic press is used to maintain the pressure at 150MPa~300MPa for 30min~90min.

5. The method for preparing the tungsten-rhenium-copper-infiltrated gradient material according to claim 1, characterized in that: Step 4 is specifically as follows: pressing and sintering the green body: the sintering method is to place the fine-grained tungsten-rhenium alloy powder at the bottom and the coarse-grained tungsten-rhenium alloy powder at the top vertically, using a medium-frequency sintering furnace in a hydrogen atmosphere, keeping the temperature at 600°C to 1000°C for 1h to 4h during the heating stage, and keeping the temperature at 1800°C to 2300°C for 6h to 12h during the insulation stage; to complete the further reduction of the rhenium oxide in the coating layer.

6. The method for preparing the tungsten-rhenium-copper-infiltrated gradient material according to claim 1, characterized in that: Step 5 is specifically as follows: design the size of the graphite boat according to the size of the sintered blank. During melt infiltration, the inner length L of the graphite boat needs to be determined in combination with the height h of the sintered blank to ensure that the coarse-grained sintered end of the sintered blank obtains a pure copper layer of designed thickness after the melt infiltration is completed. The inner width W of the graphite boat needs to be determined in combination with the length l of the sintered blank, and the inner height H of the graphite boat needs to be determined in combination with the width w of the sintered blank. Use the buried infiltration method for copper infiltration, and the amount of copper used is the volume of the graphite boat minus the volume of the sintered blank, that is, the required copper volume. The sintering temperature of the melt infiltration furnace is 1100℃~1500℃, and the insulation is 4h~8h.

7. The method for preparing the tungsten-rhenium-copper-infiltrated gradient material according to claim 1, characterized in that: Step 6 is specifically as follows: after the infiltration is completed, the sintered blank is machined to remove the excess copper on the outside of the sintered blank, retaining the coarse-grained pure copper layer at the sintered end, and obtaining a four-gradient tungsten-rhenium copper infiltrated gradient material consisting of a tungsten-rhenium alloy layer, a tungsten-rhenium-low copper layer, a tungsten-rhenium-high copper layer and a pure copper layer.

8. Tungsten-rhenium-copper-infiltrated gradient material, characterized in that: The invention comprises a tungsten-rhenium alloy layer, a tungsten-rhenium-less copper layer, a tungsten-rhenium-more copper layer and a pure copper layer which are arranged in sequence, and is prepared by the method according to any one of claims 1 to 7.

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