Particle-reinforced tungsten alloy shielding material and preparation method and application thereof

Abstract

The invention provides a particle-reinforced tungsten alloy shielding material as well as a preparation method and application thereof. The particle-reinforced tungsten alloy shielding material comprises a tungsten matrix and gadolinium hexaboride dispersed in the tungsten matrix, the mass of the gadolinium hexaboride is 0.01 wt%-4wt% of the mass of the particle reinforced tungsten alloy shielding material. According to the invention, by using the gadolinium hexaboride with specific mass percentage content, the radiation damage of the tungsten alloy is avoided by utilizing the shielding capability of gadolinium and boron elements on neutron radiation; and meanwhile, gadolinium hexaboride is stable in property and has a particle reinforcing effect, so that the mechanical property of the tungsten alloy is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of metallurgy, in particular to a shielding material, and in particular to a particle-reinforced tungsten alloy shielding material, a preparation method thereof, and an application thereof. Background Art

[0002] When a nuclear reactor is operating, the core will produce a variety of radiation (α, β, γ, χ) as well as neutrons (n), protons (p), deuterium nuclei (d), and fission products (FP). Among them, radiation (γ) and neutrons have strong penetrating power. If they are not properly shielded, they will cause certain radiation damage to surrounding objects and personnel.

[0003] Materials with high atomic numbers are more effective for shielding gamma rays. Metals like steel, lead, and tungsten, their alloys, and composite materials are more effective. The order of shielding effectiveness is tungsten > lead > steel. Conversely, unlike gamma rays, alloys containing elements with low atomic numbers, such as hydrogen and boron, are more effective for shielding neutrons.

[0004] Tungsten has good radiation shielding ability, but its neutron shielding ability is poor and cannot meet the requirements of shielding both radiation and neutron radiation.

[0005] Therefore, it is necessary to provide a particle-reinforced tungsten alloy shielding material having good neutron shielding capability and being easy to process and produce, as well as a preparation method and application thereof. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the object of the present invention is to provide a particle-reinforced tungsten alloy shielding material and a preparation method and application thereof, wherein the particle-reinforced tungsten alloy shielding material has good neutron radiation shielding capability and good mechanical properties.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a particle-reinforced tungsten alloy shielding material, the particle-reinforced tungsten alloy shielding material comprising a tungsten matrix and gadolinium hexaboride dispersed in the tungsten matrix;

[0009] The mass of the gadolinium hexaboride is 0.01 wt%-4 wt% of the particle-reinforced tungsten alloy shielding material.

[0010] The present invention uses gadolinium hexaboride with a specific mass percentage and utilizes the shielding ability of gadolinium and boron elements against neutron radiation to avoid tungsten alloy radiation damage. At the same time, gadolinium hexaboride has stable properties and a particle reinforcement effect, which further improves the mechanical properties of the tungsten alloy.

[0011] Preferably, the mass of the gadolinium hexaboride is 0.1 wt%-4 wt% of the particle-reinforced tungsten alloy shielding material.

[0012] In a second aspect, the present invention provides a method for preparing the particle-reinforced tungsten alloy shielding material according to the first aspect, the preparation method comprising the following steps:

[0013] A tungsten source and gadolinium hexaboride are mixed to obtain a mixture; the obtained mixture is pressed to obtain a compact; and then sintering, plastic working and annealing are sequentially performed to obtain the particle reinforced tungsten alloy shielding material.

[0014] As one of the preferred solutions of the preparation method, when the tungsten source is tungsten powder, the mixing method of the tungsten source and gadolinium hexaboride includes ball milling or V-type powder mixer mixing.

[0015] Exemplarily, the ball milling mixing method includes conventional ball milling and / or high energy ball milling.

[0016] As a second preferred solution of the preparation method, when the tungsten source is ammonium metatungstate and / or ammonium paratungstate, the method of mixing the tungsten source with gadolinium hexaboride includes: mixing, then drying and reduction sintering in sequence.

[0017] Preferably, the pressing comprises cold isostatic pressing.

[0018] Preferably, the pressing pressure is 180 MPa-250 MPa.

[0019] Preferably, the holding time of the pressing is 90s-180s.

[0020] Preferably, the sintering includes pressureless sintering or hot pressing sintering.

[0021] Preferably, the pressureless sintering temperature is 2100° C.-2400° C., and the holding time is 5 h-8 h.

[0022] Preferably, the hot pressing sintering temperature is 1700° C.-2300° C., the pressure is 20 MPa-60 MPa, and the heat and pressure holding time is 0.5 h-2 h.

[0023] Preferably, the plastic working includes rotary forging or rolling.

[0024] Preferably, the rolling temperature is 1500° C.-1800° C., and the rolling deformation is 50%-80%.

[0025] Preferably, the annealing treatment temperature is 900° C.-1200° C., and the holding time is 1 h-2 h.

[0026] In a third aspect, the present invention provides a tokamak device, comprising the particle-reinforced tungsten alloy shielding material according to the first aspect.

[0027] The numerical range described in the present invention includes not only the point values ​​listed above, but also any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention uses gadolinium hexaboride with a specific mass percentage and utilizes the shielding ability of gadolinium and boron elements against neutron radiation to avoid tungsten alloy radiation damage. At the same time, gadolinium hexaboride has stable properties and a particle reinforcement effect, which further improves the mechanical properties of the tungsten alloy. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 and Figure 2 This is the SEM image of the fracture surface of the particle-reinforced tungsten alloy shielding material obtained in Example 1. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0032] A certain embodiment of the present invention provides a particle-reinforced tungsten alloy shielding material, wherein the particle-reinforced tungsten alloy shielding material includes a tungsten matrix and gadolinium hexaboride dispersed in the tungsten matrix;

[0033] The mass of the gadolinium hexaboride is 0.01wt%-4wt% of the particle-reinforced tungsten alloy shielding material, for example, it can be 0.01wt%, 0.05wt%, 0.1wt%, 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt% or 4wt%, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable, preferably 0.1wt%-4wt%.

[0034] The present invention uses gadolinium hexaboride with a specific mass percentage and utilizes the shielding ability of gadolinium and boron elements against neutron radiation to avoid tungsten alloy radiation damage. At the same time, gadolinium hexaboride has stable properties and a particle reinforcement effect, which further improves the mechanical properties of the tungsten alloy.

[0035] A certain embodiment of the present invention provides a method for preparing the particle-reinforced tungsten alloy shielding material described in any embodiment, the method comprising the following steps:

[0036] A tungsten source and gadolinium hexaboride are mixed to obtain a mixture; the obtained mixture is pressed to obtain a compact; and then sintering, plastic working and annealing are sequentially performed to obtain the particle reinforced tungsten alloy shielding material.

[0037] In certain embodiments, when the tungsten source is tungsten powder, a method for mixing the tungsten source with gadolinium hexaboride includes ball milling or V-type powder mixer mixing.

[0038] Exemplarily, the ball milling mixing method includes conventional ball milling and / or high energy ball milling.

[0039] In order to take into account the ball milling mixing effect and the preparation efficiency of the particle-reinforced tungsten alloy shielding material, the ball milling time is 24h-72h, for example, it can be 24h, 30h, 40h, 50h, 60h or 72h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0040] In some embodiments, the tungsten powder has a Fisher particle size of 0.7 μm-5 μm, for example, 0.7 μm, 1 μm, 1.2 μm, 1.5 μm, 1.8 μm, 2 μm, 3 μm, 4 μm, or 5 μm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0041] In certain embodiments, the gadolinium hexaboride has a Fisher particle size of 0.1 μm to 20 μm, for example, 0.5 μm, 1 μm, 1 μm, 3 μm, 5 μm, 8 μm, 10 μm, 15 μm, or 20 μm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0042] In certain embodiments, when the tungsten source is ammonium metatungstate and / or ammonium paratungstate, the method of mixing the tungsten source with gadolinium hexaboride includes: mixing, then drying and reduction sintering in sequence.

[0043] In certain embodiments, the method of drying comprises spray drying.

[0044] In certain embodiments, the inlet temperature of the spray drying is 280°C-300°C, for example, 280°C, 290°C, 300°C, 310°C or 320°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0045] In certain embodiments, the outlet temperature of the spray drying is 120°C-140°C, for example, 120°C, 125°C, 130°C, 135°C or 140°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0046] In certain embodiments, the spray drying liquid spray rate is 8 L / h-12 L / h, for example, it can be 8 L / h, 9 L / h, 10 L / h, 11 L / h or 12 L / h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0047] In certain embodiments, the rotation speed of the atomizing disk of the spray drying is 1800 rpm-2200 rpm, for example, it can be 1800 rpm, 1900 rpm, 2000 rpm, 2100 rpm or 2200 rpm, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0048] In some embodiments, the reduction sintering is performed in a hydrogen atmosphere, the hydrogen flow rate is 3 L / min-5 L / min, the temperature is 900-1000° C., and the boat pushing speed is 14 min / boat-16 min / boat.

[0049] In certain embodiments, the pressing comprises cold isostatic pressing.

[0050] In certain embodiments, the pressing pressure is 180 MPa-250 MPa, for example, 180 MPa, 200 MPa, 210 MPa, 240 MPa or 250 MPa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0051] In some embodiments, the holding time of the pressing is 90s-180s, for example, it can be 90s, 100s, 120s, 150s, 160s or 180s, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0052] In certain embodiments, the sintering includes pressureless sintering or hot pressing sintering.

[0053] In certain embodiments, the pressureless sintering is performed in a hydrogen atmosphere.

[0054] In certain embodiments, the hot pressing sintering is performed in a vacuum.

[0055] In some embodiments, the pressureless sintering temperature is 2100° C.-2400° C., and the holding time is 5 h-8 h.

[0056] The pressureless sintering temperature is 2100°C-2400°C, for example, 2100°C, 2150°C, 2200°C, 2250°C, 2300°C, 2350°C or 2400°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0057] The holding time of the pressureless sintering is 5 hours to 8 hours, for example, 5 hours, 6 hours, 7 hours or 8 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0058] In some embodiments, the hot pressing sintering is performed at a temperature of 1700° C. to 2300° C., a pressure of 20 MPa to 60 MPa, and a heat and pressure holding time of 0.5 h to 2 h.

[0059] The temperature of the hot pressing sintering is 1700°C-2300°C, for example, it can be 1700°C, 1800°C, 2000°C, 2100°C, 2200°C or 2300°C, but is not limited to the listed values. Other values ​​not listed in the numerical range are also applicable, preferably 1800°C-2100°C.

[0060] The pressure of the hot pressing sintering is 20 MPa-60 MPa, for example, 20 MPa, 30 MPa, 40 MPa, 50 MPa or 60 MPa, but is not limited to the listed values. Other values ​​not listed in the numerical range are also applicable, preferably 30 MPa-40 MPa.

[0061] The heat preservation and pressure holding time of the hot pressing sintering is 0.5h-2h, for example, it can be 0.5h, 0.8h, 1h, 1.2h, 1.5h, 1.8h or 2h, but is not limited to the listed values. Other values ​​not listed in the numerical range are also applicable, preferably 0.5h-1h.

[0062] In certain embodiments, the plastic working includes rotary swaging or rolling.

[0063] In some embodiments, the rolling temperature is 1500° C.-1800° C., and the rolling deformation is 50%-80%.

[0064] The rolling temperature is 1500°C-1800°C, for example, it can be 1500°C, 1550°C, 1600°C, 1650°C, 1700°C, 1750°C or 1800°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0065] The rolling deformation of the rolling is 50%-80%, for example, it can be 50%, 60%, 70% or 80%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0066] In some embodiments, the annealing treatment is performed at a temperature of 900° C. to 1200° C. and the holding time is 1 hour to 2 hours.

[0067] The temperature of the annealing treatment is 900° C.-1200° C., for example, 900° C., 1000° C., 1050° C., 1100° C. or 1200° C., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0068] The holding time of the annealing treatment is 1 h to 2 h, for example, 1 h, 1.2 h, 1.5 h, 1.8 h or 2 h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0069] A certain embodiment of the present invention provides a tokamak device, which includes the particle-reinforced tungsten alloy shielding material described in any embodiment.

[0070] Example 1

[0071] This embodiment provides a particle-reinforced tungsten alloy shielding material, which includes a tungsten matrix and gadolinium hexaboride dispersed in the tungsten matrix;

[0072] The mass of the gadolinium hexaboride is 1 wt % of the particle-reinforced tungsten alloy shielding material.

[0073] The preparation method of the particle reinforced tungsten alloy shielding material described in this embodiment includes the following steps:

[0074] (1) The formulated amount of tungsten powder (Ferris particle size 2 μm) and gadolinium hexaboride (Ferris particle size 0.5 μm) were placed in a ball mill with a ball-to-material ratio of 10:1. The mixture was ball milled at a speed of 50 rpm for 48 h to uniformly mix the tungsten powder and gadolinium hexaboride to obtain a mixed powder;

[0075] (2) The mixed powder was placed in a cold isostatic pressing mold (the rubber mold size was 32 mm × 200 mm × 250 mm, and the outer stainless steel sleeve size was 40 mm × 230 mm × 200 mm), and then placed in a cold isostatic press for pressing. The cold isostatic pressing pressure was 200 MPa and the holding time was 180 s. After demolding, a 30 mm × 180 mm × 180 mm green compact was obtained.

[0076] (3) The obtained compact is subjected to normal pressure sintering in a hydrogen atmosphere to obtain a tungsten alloy; the normal pressure sintering temperature is 2200° C. and the holding time is 8 hours;

[0077] (4) The tungsten alloy in step (3) is rolled with a rolling deformation of 66% and a rolling temperature of 1600° C.; and then annealed at 1200° C. for 1 h to obtain the particle-reinforced tungsten alloy shielding material.

[0078] The fracture SEM image of the particle reinforced tungsten alloy shielding material obtained in this embodiment is shown in FIG. Figure 1 and Figure 2 shown.

[0079] Example 2

[0080] This embodiment provides a particle-reinforced tungsten alloy shielding material, which includes a tungsten matrix and gadolinium hexaboride dispersed in the tungsten matrix;

[0081] The mass of the gadolinium hexaboride is 0.5 wt % of the particle-reinforced tungsten alloy shielding material.

[0082] The preparation method of the particle reinforced tungsten alloy shielding material described in this embodiment includes the following steps:

[0083] (1) The formulated amount of tungsten powder (Ferris particle size 5 μm) and gadolinium hexaboride (Ferris particle size 20 μm) were placed in a ball mill with a ball-to-material ratio of 10:1. The tungsten powder and gadolinium hexaboride were uniformly mixed at a speed of 220 rpm for 48 h to obtain a mixed powder.

[0084] (2) The mixed powder was placed in a cold isostatic pressing mold (the rubber mold size was 32 mm × 200 mm × 250 mm, and the outer stainless steel sleeve size was 40 mm × 230 mm × 200 mm), and then placed in a cold isostatic press for pressing. The cold isostatic pressing pressure was 180 MPa and the holding time was 180 s. After demolding, a 30 mm × 180 mm × 180 mm green compact was obtained.

[0085] (3) The obtained compact is subjected to normal pressure sintering in a hydrogen atmosphere to obtain a tungsten alloy; the normal pressure sintering temperature is 2300° C. and the holding time is 5 hours;

[0086] (4) The tungsten alloy in step (3) is rolled with a rolling deformation of 50% and a rolling temperature of 1600° C.; and then annealed at 900° C. for 2 h to obtain the particle-reinforced tungsten alloy shielding material.

[0087] Example 3

[0088] This embodiment provides a particle-reinforced tungsten alloy shielding material, which includes a tungsten matrix and gadolinium hexaboride dispersed in the tungsten matrix;

[0089] The mass of the gadolinium hexaboride is 0.1 wt % of the particle-reinforced tungsten alloy shielding material.

[0090] The preparation method of the particle reinforced tungsten alloy shielding material described in this embodiment includes the following steps:

[0091] (1) The formulated amount of tungsten powder (Ferris particle size 0.7 μm) and gadolinium hexaboride (Ferris particle size 0.1 μm) were placed in a V-type mixer and mechanically mixed at a speed of 10 rpm for 12 h to uniformly mix the tungsten powder and gadolinium hexaboride to obtain a mixed powder;

[0092] (2) The mixed powder was placed in a cold isostatic pressing mold (the rubber mold size was 32 mm × 200 mm × 250 mm, and the outer stainless steel sleeve size was 40 mm × 230 mm × 200 mm), and then placed in a cold isostatic press for pressing. The cold isostatic pressing pressure was 250 MPa and the holding time was 90 s. After demolding, a 30 mm × 180 mm × 180 mm green compact was obtained.

[0093] (3) The obtained compact is subjected to normal pressure sintering in a hydrogen atmosphere to obtain a tungsten alloy; the normal pressure sintering temperature is 2300° C. and the holding time is 5 hours;

[0094] (4) The tungsten alloy in step (3) is rolled with a rolling deformation of 80% and a rolling temperature of 1600° C.; and then annealed at 1200° C. for 1 h to obtain the particle-reinforced tungsten alloy shielding material.

[0095] Example 4

[0096] This embodiment provides a particle-reinforced tungsten alloy shielding material, which is the same as that of Example 1 except that the mass of gadolinium hexaboride is 0.01 wt % of the particle-reinforced tungsten alloy shielding material.

[0097] Example 5

[0098] This embodiment provides a particle-reinforced tungsten alloy shielding material, which is the same as that of Example 1 except that the mass of gadolinium hexaboride accounts for 4 wt % of the particle-reinforced tungsten alloy shielding material.

[0099] Example 6

[0100] This embodiment provides a particle-reinforced tungsten alloy shielding material. Except for step (3) in the preparation method, which is different from that in Example 1, the rest is the same as that in Example 1.

[0101] Step (3) of this embodiment is: hot pressing and sintering the obtained compact in vacuum to obtain tungsten alloy; the hot pressing and sintering temperature is 1800° C., the pressure is 40 MPa, and the heat and pressure holding time is 1 hour.

[0102] Example 7

[0103] This embodiment provides a particle-reinforced tungsten alloy shielding material. Except for step (3) in the preparation method, which is different from that in Example 1, the rest is the same as that in Example 1.

[0104] Step (3) of this embodiment is: hot pressing and sintering the obtained compact in vacuum to obtain tungsten alloy; the hot pressing and sintering temperature is 2000° C., the pressure is 30 MPa, and the heat and pressure holding time is 0.5 h.

[0105] Example 8

[0106] This embodiment provides a particle-reinforced tungsten alloy shielding material. Except for step (3) in the preparation method, which is different from that in Example 1, the rest is the same as that in Example 1.

[0107] Step (3) of this embodiment is: hot pressing and sintering the obtained compact under vacuum to obtain tungsten alloy; the hot pressing and sintering temperature is 2100°C, the pressure is 30 MPa, and the heat and pressure holding time is 0.5h.

[0108] Example 9

[0109] This embodiment provides a particle-reinforced tungsten alloy shielding material, which includes a tungsten matrix and gadolinium hexaboride dispersed in the tungsten matrix;

[0110] The mass of the gadolinium hexaboride is 0.5 wt % of the particle-reinforced tungsten alloy shielding material.

[0111] The preparation method of the particle reinforced tungsten alloy shielding material described in this embodiment includes the following steps:

[0112] (1) Ammonium paratungstate and gadolinium hexaboride were mixed in proportion, and deionized water was added at a weight ratio of 4:1; the mixed materials were then placed in a ball mill to a ball-to-material ratio of 3:1, and ball milled at a speed of 50 rpm for 24 hours to obtain a ball milled material;

[0113] (2) spray drying the ball milled material at an inlet temperature of 290°C, an outlet temperature of 130°C, a spray rate of 10 L / h, and an atomizing disk speed of 2000 rpm to obtain granulated material; the obtained granulated material was reduced in a hydrogen reduction furnace at a hydrogen flow rate of 4 L / min, a temperature of 1000°C, and a boat pushing speed of 15 min / boat to obtain raw material powder;

[0114] (3) The raw material powder is loaded into a cold isostatic pressing mold (the size of the rubber mold is 32 mm × 200 mm × 250 mm, and the size of the outer stainless steel sleeve is 40 mm × 230 mm × 200 mm), and then placed in a cold isostatic press for pressing. The cold isostatic pressing pressure is 200 MPa and the holding time is 180 s. After demolding, a 30 mm × 180 mm × 180 mm green compact is obtained. The green compact is sintered at normal pressure in a hydrogen atmosphere to obtain a tungsten alloy. The temperature of the normal pressure sintering is 2200 ° C and the holding time is 8 h.

[0115] (4) The tungsten alloy in step (3) is rolled with a rolling deformation of 66% and a rolling temperature of 1600° C.; and then annealed at 1200° C. for 1 h to obtain the particle-reinforced tungsten alloy shielding material.

[0116] Comparative Example 1

[0117] This comparative example provides a tungsten alloy shielding material, which differs from Example 1 in that gadolinium hexaboride is not added when preparing the tungsten alloy shielding material.

[0118] Comparative Example 2

[0119] This comparative example provides a tungsten alloy shielding material, which is the same as Example 1 except that gadolinium hexaboride is replaced with lanthanum hexaboride.

[0120] Comparative Example 3

[0121] This comparative example provides a tungsten alloy shielding material, which is the same as Example 1 except that the mass of gadolinium hexaboride is 5 wt % of the tungsten alloy shielding material.

[0122] Performance Characterization

[0123] The neutron shielding performance of the particle-reinforced tungsten alloy shielding materials provided in Example 1, Comparative Example 2, and Comparative Example 3 was tested. The neutron shielding performance test method is based on the Beijing Radiation Application Research Center Enterprise Standard "Q / CYSXY 001-2016". The results are shown in Table 1.

[0124] Table 1

[0125] Neutron transmittance Example 1 ≤2％ Comparative Example 1 17％ Comparative Example 2 12.5％

[0126] As can be seen from Table 1, compared to the tungsten alloy shielding material of Comparative Example 1, which does not contain gadolinium hexaboride, and the tungsten alloy shielding material of Comparative Example 2, which contains 1 wt% lanthanum hexaboride, the tungsten-based alloy of Example 1 significantly decreases in neutron transmittance by adding 1 wt% gadolinium hexaboride, indicating that the addition of gadolinium hexaboride can significantly improve the neutron shielding performance of the tungsten-based alloy. Since the lanthanum in lanthanum hexaboride does not have the ability to shield neutrons, only boron has the ability to shield neutrons, and gadolinium does have the ability to shield neutrons, the neutron shielding effect of adding gadolinium hexaboride is better than that of adding lanthanum hexaboride.

[0127] The thermal conductivity and hardness of the particle-reinforced tungsten alloy shielding materials provided in Examples 1 to 9 and the tungsten alloy shielding materials provided in Comparative Examples 1 to 3 were tested, and the results are shown in Table 2.

[0128] The test method for thermal conductivity is: GB / T 22588-2008 "Flash method for measuring thermal diffusivity or thermal conductivity";

[0129] Hardness measurement method: GB / T4340 "Vickers hardness test for metallic materials".

[0130] Table 2

[0131] Thermal conductivity (W / (m·K)) Vickers hardness (HV10) Example 1 165 459 Example 2 167 448 Example 3 170 439 Example 4 171 422 Example 5 155 481 Example 6 165 459 Example 7 166 459 Example 8 165 459 Example 9 168 448 Comparative Example 1 172 422 Comparative Example 2 162 465 Comparative Example 3 - -

[0132] Note: The tungsten alloy prepared in Example 3 cracked during rolling and did not meet the standard, so the Vickers hardness was not tested again.

[0133] As can be seen from Table 2, the particle reinforced tungsten alloy shielding material obtained by adding gadolinium hexaboride in the present invention can be prepared by thermoplastic processing, and has a hardness of more than 422 and a thermal conductivity of more than 160 W / (m·k); however, the amount of gadolinium hexaboride added has a preferred selection. When the mass of gadolinium hexaboride is 0.1wt%-4wt% of the particle reinforced tungsten alloy shielding material, the hardness of the obtained particle reinforced tungsten alloy shielding material can reach more than 439 HV, and the thermal conductivity is more than 155 W / (m·k); however, too high an amount of gadolinium hexaboride added is not conducive to the performance of thermoplastic processing. For example, when the mass of gadolinium hexaboride is 5wt% of the particle reinforced tungsten alloy shielding material, the obtained particle reinforced tungsten alloy shielding material has the problem of rolling cracking and cannot be used.

[0134] In summary, the present invention utilizes a specific mass percentage of gadolinium hexaboride to shield the tungsten alloy from neutron damage by utilizing the shielding capabilities of gadolinium and boron. Furthermore, gadolinium hexaboride is stable and has a particle reinforcement effect, further improving the mechanical properties of the tungsten alloy.

[0135] The applicant declares that the above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A particle reinforced tungsten alloy shielding material, characterized in that: The particle-reinforced tungsten alloy shielding material includes a tungsten matrix and gadolinium hexaboride dispersed in the tungsten matrix; The mass of the gadolinium hexaboride is 0.01 wt%-4 wt% of the particle-reinforced tungsten alloy shielding material.

2. The particle-reinforced tungsten alloy shielding material according to claim 1, characterized in that: The mass of the gadolinium hexaboride is 0.1 wt%-4 wt% of the particle-reinforced tungsten alloy shielding material.

3. A method for preparing the particle-reinforced tungsten alloy shielding material according to claim 1 or 2, characterized in that: The preparation method comprises the following steps: A tungsten source and gadolinium hexaboride are mixed to obtain a mixture; the obtained mixture is pressed to obtain a compact; and then sintering, plastic working and annealing are sequentially performed to obtain the particle reinforced tungsten alloy shielding material.

4. The preparation method according to claim 3, characterized in that The tungsten source is tungsten powder; The mixing method of the tungsten source and gadolinium hexaboride includes ball mill mixing or V-type powder mixer mixing.

5. The preparation method according to claim 3, characterized in that The tungsten source is ammonium metatungstate and / or ammonium paratungstate; The method for mixing the tungsten source and gadolinium hexaboride includes: mixing, then drying and reduction sintering in sequence.

6. The preparation method according to claim 3, characterized in that The pressing comprises cold isostatic pressing; Preferably, the pressing pressure is 180MPa-250MPa; Preferably, the holding time of the pressing is 90s-180s.

7. The preparation method according to claim 3, characterized in that The sintering includes normal pressure sintering or hot pressing sintering; Preferably, the pressureless sintering temperature is 2100° C.-2400° C., and the holding time is 5 h-8 h; Preferably, the hot pressing sintering temperature is 1700° C.-2300° C., the pressure is 20 MPa-60 MPa, and the heat and pressure holding time is 0.5 h-2 h.

8. The preparation method according to claim 3, characterized in that The plastic working includes rotary forging or rolling; Preferably, the rolling temperature is 1500° C.-1800° C., and the rolling deformation is 50%-80%.

9. The preparation method according to any one of claims 3 to 8, characterized in that The annealing treatment temperature is 900° C.-1200° C., and the holding time is 1 hour-2 hours.

10. A tokamak device, characterized in that: The tokamak device includes the particle-reinforced tungsten alloy shielding material according to claim 1 or 2.

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