Particle reinforced tungsten-copper alloy shielding material, tungsten-copper alloy heat dissipation piece and preparation method and application of particle reinforced tungsten-copper alloy shielding material and tungsten-copper alloy heat dissipation piece

Abstract

The invention belongs to the field of metal composite materials, and particularly relates to a particle-reinforced tungsten-copper alloy shielding material, a tungsten-copper alloy heat dissipation piece and a preparation method and application of the particle-reinforced tungsten-copper alloy shielding material. The particle-reinforced tungsten-copper alloy shielding material comprises a tungsten-copper alloy and gadolinium hexaboride and / or europium hexaboride dispersed in the tungsten-copper alloy, and the total content of the gadolinium hexaboride and the europium hexaboride in the particle-reinforced tungsten-copper alloy shielding material is 0.1 wt%-4wt%. The particle reinforced tungsten copper alloy shielding material provided by the invention has excellent neutron shielding capability and mechanical property.

Description

Technical Field

[0001] The present invention belongs to the field of metal composite materials, and in particular relates to a particle-reinforced tungsten-copper alloy shielding material and a tungsten-copper alloy heat sink, as well as a preparation method and application thereof. Background Art

[0002] Tungsten-copper alloy is a pseudo-alloy of tungsten and copper. Tungsten has a high melting point, high hardness, and excellent radiation resistance, making it able to withstand high temperatures and strong radiation. Copper, on the other hand, has excellent thermal conductivity, effectively conducting heat away from high-temperature areas. Therefore, tungsten-copper alloy can be used as a heat sink in nuclear fusion devices, helping to dissipate the enormous heat generated by nuclear fusion reactions. To achieve good heat dissipation, the thermal conductivity of tungsten-copper alloy must be no less than 150W / (m·K).

[0003] During the nuclear fusion reaction, various radiations such as rays and neutrons are generated. Among them, gamma rays and neutrons have strong penetrating power. If they are not properly shielded, they will cause certain radiation damage to surrounding objects and personnel. The plasma facing component (PFC) needs to withstand severe heat flux loads and a certain amount of neutron radiation. Tungsten is an excellent material for radiation shielding. Its radiation shielding ability is three times that of lead. The density of tungsten is 19.3g / cm 3 Tungsten's density gives it a significant advantage in the field of shielding, and it can effectively shield various radiations, including gamma rays. However, copper has poor ray shielding and neutron shielding capabilities.

[0004] Furthermore, research has shown that the core generates a variety of radiation, including gamma rays and neutrons. Gamma rays and neutrons are particularly penetrating, and without adequate shielding, they can cause radiation damage to surrounding objects and personnel. However, copper has weak gamma-ray and neutron shielding capabilities. While tungsten has good gamma-ray shielding capabilities, its neutron shielding capabilities are poor, making it incapable of simultaneously shielding against both gamma-ray and neutron radiation. Consequently, it cannot meet the heat flux load and neutron shielding requirements of a tokamak.

[0005] Therefore, there is an urgent need to enhance the shielding ability of tungsten-copper alloy against neutron irradiation to avoid irradiation damage and improve the mechanical properties of tungsten-copper alloy.

[0006] In view of this, the present invention is proposed. Summary of the Invention

[0007] The first purpose of the present invention is to overcome the defect that the existing tungsten-copper alloy cannot have both good neutron shielding ability and mechanical properties, and to provide a particle-reinforced tungsten-copper alloy shielding material with excellent neutron shielding ability and mechanical properties.

[0008] The second object of the present invention is to provide a method for preparing the particle reinforced tungsten-copper alloy shielding material.

[0009] The third object of the present invention is to provide a tungsten-copper alloy heat sink made of the above-mentioned particle-reinforced tungsten-copper alloy shielding material.

[0010] A fourth object of the present invention is to provide an application of the above-mentioned tungsten-copper alloy heat sink in a tokamak device.

[0011] Specifically, the particle-reinforced tungsten-copper alloy shielding material provided by the present invention comprises a tungsten-copper alloy and gadolinium hexaboride and / or europium hexaboride dispersed in the tungsten-copper alloy. The total content of gadolinium hexaboride and europium hexaboride in the particle-reinforced tungsten-copper alloy shielding material is 0.1 wt% to 4 wt%.

[0012] In a preferred embodiment, gadolinium hexaboride and europium hexaboride are dispersed in the particle-reinforced tungsten-copper alloy shielding material.

[0013] In a preferred embodiment, the mass ratio of gadolinium hexaboride to europium hexaboride in the particle-reinforced tungsten-copper alloy shielding material is (0.0005-0.04):1.

[0014] In a preferred embodiment, the particle-reinforced tungsten-copper alloy shielding material satisfies the following conditions A and / or B:

[0015] A. The copper content in the particle-reinforced tungsten-copper alloy shielding material is 5wt% to 20wt%;

[0016] B. The thermal conductivity of the particle-reinforced tungsten-copper alloy shielding material is above 150 W / mK.

[0017] The preparation method of the particle reinforced tungsten copper alloy shielding material provided by the present invention comprises the following steps:

[0018] S1. The mixture containing tungsten and gadolinium hexaboride and / or europium hexaboride is pressed to obtain a pressed part;

[0019] S2. The pressed part is sintered to obtain a sintered part;

[0020] S3. Infiltrate the sintered part with copper to obtain a particle-reinforced tungsten-copper alloy shielding material.

[0021] In a preferred embodiment, the mixture is mixture I and / or mixture II; the preparation method of the mixture I comprises mixing tungsten powder with gadolinium hexaboride and / or europium hexaboride to obtain mixture I; the preparation method of the mixture II comprises ball milling ammonium paratungstate and / or ammonium metatungstate with gadolinium hexaboride and / or europium hexaboride in the presence of an inert liquid medium, and then drying and reducing the obtained ball-milled material in sequence to obtain mixture II.

[0022] In a preferred embodiment, the preparation process of the mixture I satisfies at least one of the following conditions Aˋ-Cˋ:

[0023] A. The tungsten powder has a Fisher particle size of 3 μm to 10 μm;

[0024] Bˋ. The gadolinium hexaboride and europium hexaboride have a Fisher particle size of each independently 0.1 μm to 10 μm;

[0025] Cˋ. The mixing method includes high-energy ball milling of tungsten powder I and gadolinium hexaboride and / or europium hexaboride, and stirring and mixing the resulting ball-milled material with tungsten powder II.

[0026] In a preferred embodiment, the preparation process of the mixture II satisfies at least one of the following conditions Dˋ-Hˋ:

[0027] Dˋ. The inert liquid medium is water;

[0028] Eˋ. The amount of the inert liquid medium is such that the material-liquid mass ratio is (1 to 5): 1;

[0029] Fˋ The ball milling conditions include a speed of 10rpm ~ 100rpm and a time of 10h ~ 48h;

[0030] Gˋ. The drying method is spray drying, and the spray drying conditions include an inlet temperature of 280 ℃ ~ 300 ℃, an outlet temperature of 120 ℃ ~ 140 ℃, a spray rate of 1L / h ~ 10L / h, and an atomizing disk speed of 1000rpm ~ 3000rpm;

[0031] Hˋ. The reduction treatment conditions include a hydrogen atmosphere, a hydrogen flow rate of 3 to 5 L / min, a maximum temperature of 900°C to 1000°C, and a boat pushing speed of 10 to 20 min / boat.

[0032] In a preferred embodiment, during the preparation of the particle-reinforced tungsten-copper alloy shielding material, at least one of the following conditions Aˋˋ-Cˋˋ is satisfied:

[0033] Aˋˋ. In step S1, the pressing conditions include a pressure of 180MPa~250MPa and a holding time of 90s~180s;

[0034] B ˋ ˋ In step S2, the sintering conditions include a temperature of 1800 ℃ ~ 2150 ℃, a time of 3h ~ 8h;

[0035] Cˋˋ. In step S3, the copper infiltration conditions include a temperature of 1400°C to 1600°C and a time of 0.5h to 2h.

[0036] The present invention adds gadolinium hexaboride and / or europium hexaboride to the tungsten-copper alloy. The dispersion strengthening of these two specific particles is beneficial to the refinement of the grains in the tungsten-copper alloy. The introduction of gadolinium hexaboride and / or europium hexaboride enables the tungsten-copper alloy to have neutron shielding capability, thereby extending the service life of the tungsten-copper alloy heat sink on the tokamak device. In addition, gadolinium hexaboride and europium hexaboride can also enhance the tungsten-copper alloy, thereby further improving the mechanical properties of the tungsten-copper alloy. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a scanning electron microscope (SEM) fracture image of the sintered part obtained in Example 1;

[0038] Figure 2 This is the SEM fracture image of the sintered part obtained in Example 2;

[0039] Figure 3 This is the SEM fracture image of the sintered part obtained in Example 3;

[0040] Figure 4 This is an SEM fracture image of the particle-reinforced tungsten-copper alloy shielding material obtained in Example 1;

[0041] Figure 5 This is an SEM fracture image of the particle-reinforced tungsten-copper alloy shielding material obtained in Example 2;

[0042] Figure 6 This is an SEM fracture image of the particle-reinforced tungsten-copper alloy shielding material obtained in Example 3. DETAILED DESCRIPTION

[0043] The particle-reinforced tungsten-copper alloy shielding material provided by the present invention comprises a tungsten-copper alloy and gadolinium hexaboride and / or europium hexaboride dispersed in the tungsten-copper alloy. The tungsten-copper alloy may be dispersed with gadolinium hexaboride, may be dispersed with europium hexaboride, or may be dispersed with gadolinium hexaboride and europium hexaboride. By adding a small amount of gadolinium hexaboride and / or europium hexaboride to the copper-tungsten alloy, the neutron shielding capability is obtained, which can effectively avoid irradiation damage to the copper-tungsten alloy. In addition, gadolinium hexaboride and / or europium hexaboride are stable in nature. Adding gadolinium hexaboride and / or europium hexaboride to the tungsten-copper alloy has a particle reinforcement effect, which can improve the mechanical properties of the tungsten-copper alloy. When gadolinium hexaboride and / or europium hexaboride are dispersed in the tungsten-copper alloy, the grains can be refined because the additives are dispersed in the alloy in the form of fine particles, which can hinder grain boundary migration, thereby improving the mechanical properties of the tungsten-copper alloy.

[0044] Furthermore, the mass ratio of gadolinium hexaboride to europium hexaboride in the particle-reinforced tungsten-copper alloy shielding material is preferably (0.0005-0.04):1, which can ensure sufficient dispersion distribution. Specifically, the mass ratio of gadolinium hexaboride to europium hexaboride is preferably 0.0005:1, 0.001:1, 0.003:1, 0.005:1, 0.006:1, 0.01:1, 0.012:1, 0.014:1, 0.016:1, 0.018:1, 0.02:1, 0.025:1, 0.03:1, 0.035:1, 0.04:1, or any value therebetween.

[0045] In the present invention, the total content of gadolinium hexaboride and europium hexaboride in the particle-reinforced tungsten-copper alloy shielding material is 0.1wt% to 4wt%, such as 0.1wt%, 0.5wt%, 0.8wt%, 1wt%, 1.2wt%, 1.5wt%, 1.8wt%, 2wt%, 2.2wt%, 2.5wt%, 2.8wt%, 3wt%, 3.2wt%, 3.5wt%, 3.8wt%, 4wt% or any value therebetween. If the total content of gadolinium hexaboride and europium hexaboride in the particle-reinforced tungsten-copper alloy shielding material is less than 0.1wt%, a good neutron shielding effect cannot be achieved; if the total content of gadolinium hexaboride and europium hexaboride in the particle-reinforced tungsten-copper alloy shielding material is more than 4wt%, the thermal conductivity of the tungsten-copper alloy will be lower than 150W / mK, which is not conducive to heat transfer and cannot meet the use requirements of the heat sink material of the nuclear fusion device.

[0046] In the present invention, the copper content in the particle reinforced tungsten copper alloy shielding material is preferably 5wt% to 20wt%, specifically 5wt%, 8wt%, 10wt%, 12wt%, 15wt%, 18wt%, 20wt% or any value therebetween.

[0047] In the present invention, the thermal conductivity of the particle reinforced tungsten copper alloy shielding material is greater than 150 W / mK, and specifically can be 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250 W / mK or any value therebetween.

[0048] The preparation method of the particle reinforced tungsten copper alloy shielding material provided by the present invention comprises the following steps:

[0049] S1. The mixture containing tungsten and gadolinium hexaboride and / or europium hexaboride is pressed to obtain a pressed part;

[0050] S2. The pressed part is sintered to obtain a sintered part;

[0051] S3. Infiltrate the sintered part with copper to obtain a particle-reinforced tungsten-copper alloy shielding material.

[0052] In the preparation process of the above-mentioned particle-reinforced tungsten-copper alloy shielding material, in step S1, the mixture contains metallic tungsten and gadolinium hexaboride and / or europium hexaboride, and there is no special limitation on its source. The mixture can be mixture I, mixture II, or a composite of mixture I and mixture II. The preparation method of the mixture I comprises mixing tungsten powder with gadolinium hexaboride and / or europium hexaboride to obtain mixture I. The preparation method of the mixture II comprises ball-milling ammonium paratungstate and gadolinium hexaboride and / or europium hexaboride in the presence of an inert liquid medium, and then drying and reducing the obtained ball-milled material in sequence to obtain mixture II.

[0053] During the preparation of mixed material I, the mixing method preferably includes high-energy ball milling of tungsten powder I and gadolinium hexaboride and / or europium hexaboride, and stirring and mixing the resulting ball-milled material with tungsten powder II. Since high-energy ball milling will break up tungsten powder I and gadolinium hexaboride and / or europium hexaboride, without secondary stirring and mixing, it will be difficult to form after pressing. The mass ratio of the amount of tungsten powder I to the total amount of gadolinium hexaboride and / or europium hexaboride is preferably (1-5):1. The amount of tungsten powder II is preferably such that the mass of gadolinium hexaboride and / or europium hexaboride is 0.5-1.5% of the total mass of the ball-milled material and tungsten powder II. The Fisher particle size of the tungsten powder is preferably 3μm to 10μm, such as 3μm, 5μm, 8μm, 10μm, or any value therebetween. The gadolinium hexaboride and europium hexaboride preferably have a Fisher particle size independently of each other of 0.1 μm to 10 μm, such as 0.1 μm, 0.5 μm, 1 μm, 2 μm, 4 μm, 6 μm, 8 μm, 10 μm or any value therebetween.

[0054] During the preparation of mixed material II, the ball milling is carried out in the presence of an inert liquid medium. The inert liquid medium can be water. The amount of the inert liquid medium is preferably such that the material-liquid mass ratio is (1 to 5):1, such as 1:1, 2:1, 3:1, 4:1, 5:1 or any value therebetween. The conditions for the ball milling preferably include a rotation speed of 10 rpm to 100 rpm, such as 10 rpm, 20 rpm, 30 rpm, 40 rpm, 50 rpm, 60 rpm, 70 rpm, 80 rpm, 90 rpm, 100 rpm or any value therebetween; and a time of 10 h to 48 h, such as 10 h, 12 h, 15 h, 18 h, 20 h, 22 h, 25 h, 28 h, 30 h, 32 h, 35 h, 38 h, 40 h, 44 h, 48 h or any value therebetween. The drying method is preferably spray drying. The spray drying conditions preferably include an inlet temperature of 280°C to 300°C, such as 280°C, 285°C, 290°C, 295°C, 300°C or any value therebetween; an outlet temperature of 120°C to 140°C, such as 120°C, 122°C, 125°C, 128°C, 130°C, 132°C, 135°C, 138°C, 140°C or any value therebetween; a liquid spray rate of 1L / h to 10L / h, such as 1, 2, 4, 6, 8, 10L / h or any value therebetween; and a rotational speed of the atomizing disk of 1000rpm to 3000rpm, such as 1000rpm, 1200rpm, 1400rpm, 1600rpm, 1800rpm, 2000rpm, 2200rpm, 2400rpm, 2600rpm, 2800rpm, 3000rpm or any value therebetween. The reduction treatment atmosphere is preferably hydrogen, and the hydrogen flow rate is preferably 3 to 5 L / min, such as 3, 3.5, 4, 4.5, 5 L / min, or any value therebetween. The maximum temperature of the reduction treatment is preferably 900°C to 1000°C, such as 900°C, 920°C, 940°C, 960°C, 980°C, 1000°C, or any value therebetween. The boat pushing speed is preferably 10 to 20 min / boat, such as 10, 12, 14, 16, 18, 20 min / boat, or any value therebetween.

[0055] In the preparation process of the above-mentioned particle reinforced tungsten copper alloy shielding material, in step S1, the pressing conditions preferably include a pressure of 180 MPa to 250 MPa, such as 180 MPa, 190 MPa, 200 MPa, 210 MPa, 220 MPa, 230 MPa, 240 MPa, 250 MPa or any value therebetween; the holding time is preferably 90 s to 180 s, such as 90 s, 100 s, 110 s, 120 s, 130 s, 140 s, 150 s, 160 s, 170 s, 180 s or any value therebetween.

[0056] In the preparation process of the above-mentioned particle reinforced tungsten copper alloy shielding material, in step S2, the sintering conditions preferably include a temperature of 1800°C to 2150°C, such as 1800°C, 1850°C, 1900°C, 1950°C, 2000°C, 2050°C, 2100°C, 2150°C or any value therebetween; and a time of 3h to 8h, such as 3h, 4h, 5h, 6h, 7h, 8h or any value therebetween.

[0057] In the present invention, the average porosity of the sintered part is preferably 10% to 35%. The average porosity is obtained by measuring the porosity of three different parts of the sample and calculating the average porosity. The porosity of a single sample = (1-sample density / theoretical density) × 100%, where the theoretical density is 19.35 g / cm2 of tungsten. 3 The density of the sample is determined by referring to the method in GB T 5163-2006 "Sintered metal materials (excluding cemented carbide) - Determination of density, oil content and porosity of permeable sintered metal materials".

[0058] In the preparation process of the above-mentioned particle reinforced tungsten copper alloy shielding material, in step S3, the copper infiltration conditions preferably include a temperature of 1400°C to 1600°C, such as 1400°C, 1450°C, 1500°C, 1550°C, 1600°C or any value therebetween; and a time of 0.5h to 2h, such as 0.5h, 0.8h, 1h, 1.2h, 1.5h, 1.8h, 2h or any value therebetween.

[0059] The present invention also provides a tungsten-copper alloy heat sink made of the particle-reinforced tungsten-copper alloy shielding material.

[0060] In addition, the present invention also provides the application of the above-mentioned tungsten-copper alloy heat sink in a tokamak device.

[0061] The present invention will be described in detail below through examples.

[0062] Example 1

[0063] S1. Pressing: GdB6 and tungsten powder I are charged into a ball mill at a weight ratio of 1:4. The GdB6 has a Fresnel particle size of 0.5 μm, while the Tungsten powder I has a Fresnel particle size of 6.5 μm. The ball-to-material ratio is 10:1. Ball milling is performed at 50 rpm for 48 hours to obtain a ball milled material. The ball milled material is then poured into a V-type powder mixer. Tungsten powder II of the same particle size is then added until the mass of GdB6 is 1.1% of the total mass of the GdB6 and tungsten powders. Mixing is continued for 12 hours to obtain a mixture containing tungsten and GdB6. The tungsten and GdB6 mixture is then placed into a cold isostatically pressed rubber mold with an inner cavity size of 110 x 150 x 400 mm. The mold is then mechanically vibrated and locked. The rubber mold filled with the material is placed in a cold isostatic press for pressing at a pressure of 200 MPa and a holding time of 180 s. After demolding, a pressed part of 110*130*180 is obtained.

[0064] S2. Sintering: The pressed part was placed in a medium frequency induction furnace and sintered in a hydrogen atmosphere at a sintering temperature of 1850° C. for 6 hours to obtain a sintered part having an average porosity of 22%.

[0065] S3. Copper infiltration: Place the sintered part in a copper infiltration furnace filled with copper for copper infiltration at a temperature of 1400°C for 2 hours to obtain a particle-reinforced tungsten-copper alloy shielding material.

[0066] The particle-reinforced tungsten-copper alloy shielding material comprises a tungsten-copper alloy and gadolinium hexaboride dispersed in the tungsten-copper alloy. The content of copper in the particle-reinforced tungsten-copper alloy shielding material is 11 wt % and the total content of gadolinium hexaboride is 1 wt %.

[0067] The SEM fracture images of the sintered part obtained in step S2 of this embodiment and the particle reinforced tungsten copper alloy shielding material obtained in step S3 are shown in FIG. Figure 1 and Figure 4 .from Figure 1 and Figure 4 It can be seen that both the sintered parts and the particle-reinforced tungsten-copper alloy shielding materials have a porous structure. The tungsten particles show brittle fracture before copper infiltration, and the copper-infiltrated area shows plastic fracture after copper infiltration.

[0068] Example 2

[0069] S1. Pressing: GdB6 and tungsten powder I are charged into a ball mill in a weight ratio of 1:2. The GdB6 has a Fisher particle size of 1 μm, while the tungsten powder I has a Fisher particle size of 10 μm. The ball-to-material ratio is 10:1. Ball milling is performed at 200 rpm for 48 hours to obtain a ball milled material. The ball milled material is then poured into a V-type powder mixer. Tungsten powder II of the same particle size is then added until the mass of GdB6 accounts for 0.55% of the total mass of the GdB6 and tungsten powders. Mixing is continued for 12 hours to obtain a mixture containing tungsten and GdB6. The tungsten and GdB6 mixture is then placed into a cold isostatically pressed rubber mold with an internal cavity size of 110 x 150 x 400 mm. The mold is then mechanically vibrated and locked. The rubber mold filled with the material is placed in a cold isostatic press for pressing at a pressure of 200 MPa and a holding time of 180 s. After demolding, a pressed part of 110*130*180 is obtained.

[0070] S2. Sintering: The pressed part was placed in a medium frequency induction furnace and sintered in a hydrogen atmosphere at a sintering temperature of 2050° C. for 5 hours to obtain a sintered part having an average porosity of 30.4%.

[0071] S3. Copper infiltration: Place the sintered part in a copper infiltration furnace filled with copper for copper infiltration at a copper infiltration temperature of 1600°C for 0.5 h to obtain a particle-reinforced tungsten-copper alloy shielding material.

[0072] The particle-reinforced tungsten-copper alloy shielding material comprises a tungsten-copper alloy and gadolinium hexaboride dispersed in the tungsten-copper alloy. The copper content in the particle-reinforced tungsten-copper alloy shielding material is 16 wt % and the total content of gadolinium hexaboride is 0.5 wt %.

[0073] The SEM fracture images of the sintered part obtained in step S2 of this embodiment and the particle reinforced tungsten copper alloy shielding material obtained in step S3 are shown in FIG. Figure 2 and Figure 5 .from Figure 2 and Figure 5 It can be seen that both the sintered parts and the particle-reinforced tungsten-copper alloy shielding materials have a porous structure. The tungsten particles show brittle fracture before copper infiltration, and the copper-infiltrated area shows plastic fracture after copper infiltration.

[0074] Example 3

[0075] S1. Pressing: Mix ammonium paratungstate and gadolinium hexaboride, with the gadolinium hexaboride amounting to 95.56% of the mass of ammonium paratungstate, calculated as reduced tungsten. Add deionized water to a material-liquid ratio of 4:1 by weight. Place the mixed materials into a ball mill at a ball-to-material ratio of 3:1 and mill at 50 rpm for 24 hours to obtain a ball-milled material. The ball-milled material is spray-granulated using a spray dryer with an inlet temperature of 300°C, an outlet temperature of 140°C, a spray rate of 5 L / h, and an atomizer speed of 2000 rpm. The spray-dried powder is placed into a clean molybdenum boat and reduced in a hydrogen reduction furnace using a hydrogen atmosphere at a flow rate of 4 L / min, a maximum temperature of 950°C, and a boat push rate of 15 min / boat to obtain a mixture containing tungsten and gadolinium hexaboride. The mixture containing tungsten and gadolinium hexaboride was placed into a cold isostatic pressing rubber mold with an inner cavity size of 110*150*400mm. The mold was then mechanically vibrated and locked. The filled rubber mold was then placed in a cold isostatic press and pressed at a pressure of 200MPa for 180s. After demolding, a pressed part measuring 110*130*180mm was obtained.

[0076] S2. Sintering: The pressed part was placed in a medium frequency induction furnace and sintered in a hydrogen atmosphere at a sintering temperature of 1950° C. for 3 hours to obtain a sintered part having an average porosity of 19.6%.

[0077] S3. Copper infiltration: Place the sintered part in a copper infiltration furnace filled with copper for copper infiltration at a temperature of 1500°C for 1 hour to obtain a particle-reinforced tungsten-copper alloy shielding material.

[0078] The particle-reinforced tungsten-copper alloy shielding material comprises a tungsten-copper alloy and gadolinium hexaboride dispersed in the tungsten-copper alloy. The copper content in the particle-reinforced tungsten-copper alloy shielding material is 10 wt % and the total content of gadolinium hexaboride is 4 wt %.

[0079] The SEM fracture images of the sintered part obtained in step S2 of this embodiment and the particle reinforced tungsten copper alloy shielding material obtained in step S3 are shown in FIG. Figure 3 and Figure 6 .from Figure 3 and Figure 6 It can be seen that both the sintered parts and the particle-reinforced tungsten-copper alloy shielding materials have a porous structure. The tungsten particles show brittle fracture before copper infiltration, and the copper-infiltrated area shows plastic fracture after copper infiltration.

[0080] Example 4

[0081] A particle-reinforced tungsten-copper alloy shielding material was prepared according to the method of Example 1, except that the amount of gadolinium hexaboride was adjusted during the ball milling process so that the amount of gadolinium hexaboride added to the final product was 0.1 wt %. The remaining conditions were the same as in Example 1, resulting in a particle-reinforced tungsten-copper alloy shielding material. The particle-reinforced tungsten-copper alloy shielding material included a tungsten-copper alloy and gadolinium hexaboride dispersed in the tungsten-copper alloy. The copper content in the particle-reinforced tungsten-copper alloy shielding material was 10 wt %, and the total gadolinium hexaboride content was 0.1 wt %. The porosity of the particle-reinforced tungsten-copper alloy shielding material was 21%.

[0082] Example 5

[0083] The only difference between this embodiment and embodiment 1 is that the additive gadolinium hexaboride has a Fisher particle size of 0.1 μm.

[0084] Example 6

[0085] The only difference between this embodiment and embodiment 2 is that the additive gadolinium hexaboride has a Fisher particle size of 10 μm.

[0086] Example 7

[0087] The only difference between this embodiment and embodiment 1 is that the additive gadolinium hexaboride is replaced with an equal mass of europium hexaboride.

[0088] Comparative Example 1

[0089] A tungsten-copper alloy material was prepared according to the method of Example 1, except that gadolinium hexaboride was not added during the ball milling process. The remaining conditions were the same as in Example 1 to obtain a tungsten-copper alloy. The tungsten-copper alloy material included tungsten and copper, and the copper content in the tungsten-copper alloy was 10 wt%.

[0090] Comparative Example 2

[0091] A particle-reinforced tungsten-copper alloy shielding material was prepared according to the method of Example 1, except that the amount of gadolinium hexaboride was adjusted so that the amount of gadolinium hexaboride added to the final product was 5 wt %. The other conditions were the same as in Example 1, and a particle-reinforced tungsten-copper alloy shielding material was obtained.

[0092] Test Case

[0093] (1) Neutron Shielding Coefficient: The neutron shielding performance of the particle-reinforced tungsten-copper alloy shielding materials obtained in Example 1, Example 7, and Comparative Example 1 was tested according to the method disclosed in the Beijing Radiation Application Research Center Enterprise Standard Q / CYSXY 001-2016. The results are shown in Table 1.

[0094] Table 1

[0095] project Neutron transmittance Example 1 ≤2％ Example 7 16.17％ Comparative Example 1 32.9％

[0096] From the results in Table 1, it can be seen that the introduction of gadolinium hexaboride and / or europium hexaboride into the tungsten-copper alloy can give the tungsten-copper alloy excellent neutron shielding ability.

[0097] (2) Thermal Conductivity: The thermal conductivity of the particle-reinforced tungsten-copper alloy shielding materials obtained in Examples 1-7 and Comparative Examples 1-2 was tested according to the method disclosed in GB / T 22588-2008, "Measurement of Thermal Diffusivity or Thermal Conductivity by Flash Method." The results are shown in Table 2.

[0098] (3) Metal Vickers Hardness: The metal Vickers hardness of the particle-reinforced tungsten-copper alloy shielding materials obtained in Examples 1-7 and Comparative Examples 1-2 was tested according to the method disclosed in GB / T4340 "Vickers Hardness Test for Metallic Materials." The results are shown in Table 2.

[0099] Table 2

[0100]

[0101]

[0102] The thermal conductivity of the particle-reinforced tungsten-copper alloy shielding material provided by the present invention is higher than 150W / (m·K), which can meet the use requirements of the radiator material of the nuclear fusion device, and because gadolinium hexaboride and / or europium hexaboride with neutron shielding ability are introduced, it has neutron shielding ability. At the same time, it can be seen from the results of Table 2 that the particle-reinforced tungsten-copper alloy shielding material also has excellent metal Vickers hardness. In addition, from the comparison of Example 1 and Comparative Example 1, it can be seen that when gadolinium hexaboride is not added, the metal Vickers hardness of the obtained particle-reinforced tungsten-copper alloy shielding material will decrease. From the comparison of Example 1 and Comparative Example 2, it can be seen that when the addition amount of gadolinium hexaboride and europium hexaboride in the particle-reinforced tungsten-copper alloy shielding material exceeds the upper limit, although the metal Vickers hardness can be improved, the thermal conductivity is too low, lower than 150W / (m·K), and cannot meet the use requirements of the radiator material of the nuclear fusion device.

[0103] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A particle-reinforced tungsten-copper alloy shielding material, characterized in that: The particle-reinforced tungsten-copper alloy shielding material comprises a tungsten-copper alloy and gadolinium hexaboride and / or europium hexaboride dispersed in the tungsten-copper alloy. The total content of gadolinium hexaboride and europium hexaboride in the particle-reinforced tungsten-copper alloy shielding material is 0.1 wt % to 4 wt %.

2. The particle reinforced tungsten copper alloy shielding material according to claim 1, characterized in that: Gadolinium hexaboride and europium hexaboride are dispersed in the particle-reinforced tungsten-copper alloy shielding material; Preferably, the mass ratio of gadolinium hexaboride to europium hexaboride in the particle-reinforced tungsten-copper alloy shielding material is (0.0005-0.04):

1.

3. The particle reinforced tungsten copper alloy shielding material according to claim 1 or 2, characterized in that: The particle reinforced tungsten copper alloy shielding material meets the following conditions A and / or B: A. The copper content in the particle-reinforced tungsten-copper alloy shielding material is 5wt% to 20wt%; B. The thermal conductivity of the particle-reinforced tungsten-copper alloy shielding material is above 150 W / mK.

4. The method for preparing the particle-reinforced tungsten-copper alloy shielding material according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: S1. The mixture containing tungsten and gadolinium hexaboride and / or europium hexaboride is pressed to obtain a pressed part; S2. The pressed part is sintered to obtain a sintered part; S3. Infiltrate the sintered part with copper to obtain a particle-reinforced tungsten-copper alloy shielding material.

5. The method for preparing the particle reinforced tungsten copper alloy shielding material according to claim 4, characterized in that: The mixed material is mixed material I and / or mixed material II; the preparation method of mixed material I includes mixing tungsten powder with gadolinium hexaboride and / or europium hexaboride to obtain mixed material I; the preparation method of mixed material II includes ball milling ammonium paratungstate and / or ammonium metatungstate with gadolinium hexaboride and / or europium hexaboride in the presence of an inert liquid medium, and then drying and reducing the obtained ball-milled material in sequence to obtain mixed material II.

6. The method for preparing the particle reinforced tungsten copper alloy shielding material according to claim 5, characterized in that: The preparation process of the mixture I satisfies at least one of the following conditions Aˋ-Cˋ: A. The tungsten powder has a Fisher particle size of 3 μm to 10 μm; Bˋ. The gadolinium hexaboride and europium hexaboride have a Fisher particle size of each independently 0.1 μm to 10 μm; Cˋ. The mixing method includes high-energy ball milling of tungsten powder I and gadolinium hexaboride and / or europium hexaboride, and stirring and mixing the resulting ball-milled material with tungsten powder II.

7. The method for preparing the particle reinforced tungsten copper alloy shielding material according to claim 5, characterized in that: The preparation process of the mixture II satisfies at least one of the following conditions Dˋ-Hˋ: Dˋ. The inert liquid medium is water; Eˋ. The amount of the inert liquid medium is such that the material-liquid mass ratio is (1 to 5): 1; Fˋ The ball milling conditions include a speed of 10rpm ~ 100rpm and a time of 10h ~ 48h; Gˋ. The drying method is spray drying, and the spray drying conditions include an inlet temperature of 280 ℃ ~ 300 ℃, an outlet temperature of 120 ℃ ~ 140 ℃, a spray rate of 1L / h ~ 10L / h, and an atomizing disk speed of 1000rpm ~ 3000rpm; Hˋ. The reduction treatment conditions include a hydrogen atmosphere, a hydrogen flow rate of 3 to 5 L / min, a maximum temperature of 900°C to 1000°C, and a boat pushing speed of 10 to 20 min / boat.

8. The method for preparing a particle-reinforced tungsten-copper alloy shielding material according to claim 4, characterized in that: During the preparation of the particle-reinforced tungsten-copper alloy shielding material, at least one of the following conditions Aˋˋ-Cˋˋ is met: Aˋˋ. In step S1, the pressing conditions include a pressure of 180MPa~250MPa and a holding time of 90s~180s; B ˋ ˋ In step S2, the sintering conditions include a temperature of 1800 ℃ ~ 2150 ℃, a time of 3h ~ 8h; Cˋˋ. In step S3, the copper infiltration conditions include a temperature of 1400°C to 1600°C and a time of 0.5h to 2h.

9. A tungsten-copper alloy heat sink made of the particle-reinforced tungsten-copper alloy shielding material according to any one of claims 1 to 3.

10. Use of the tungsten-copper alloy heat sink according to claim 9 in a tokamak device.

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