High-mechanical-property aluminum-based composite material for shielding neutrons and gamma rays and preparation method of high-mechanical-property aluminum-based composite material

Abstract

The invention discloses a high-mechanical-property aluminum-based composite material for shielding neutrons and gamma rays and a preparation method of the high-mechanical-property aluminum-based composite material for shielding the neutrons and the gamma rays, 6-series aluminum alloy is used as basic alloy, and tungsten boride with the volume fraction being 9-20% or mixed powder of tungsten and boron with the volume fraction sum being 9-20% is added, so that the high-mechanical-property aluminum-based composite material for shielding the neutrons and the gamma rays is obtained. The preparation method comprises the following steps: weighing raw material powder, putting the weighed raw material powder into a stainless steel tank, adding a ball milling medium and a lubricant, putting the obtained raw materials into the stainless steel tank, putting the stainless steel tank on a ball mill, carrying out vacuum ball milling to obtain a mixture, putting the mixture into a graphite mold, and carrying out hot pressing to obtain the high-strength graphite material. And heating and pressurizing in a vacuum environment or a protective atmosphere, carrying out hot pressed sintering under the conditions of heat preservation and pressure preservation, and cooling to room temperature to obtain the compact sintered block of the tungsten-boron-gadolinium-aluminum composite material. The tungsten-boron-gadolinium-aluminum composite material can achieve good neutron and gamma ray shielding at the same time, and has high application value.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear materials, and in particular relates to an aluminum-based composite material with high mechanical properties for neutron and gamma ray shielding and a preparation method thereof. Background Art

[0002] In nuclear energy and various nuclear application facilities, various radiations are inevitably generated, such as neutrons, gamma rays, heavy charged particles and beta rays. Since neutrons are not charged, it is particularly difficult to shield multiple radiations. At the same time, the interaction between neutrons and matter will excite gamma rays, and the shielding of both needs to be considered at the same time. Moreover, in many special nuclear facilities, not only is it necessary to shield the neutron / gamma ray mixed radiation field, but the shielding material is also required to have certain structural mechanical properties. Therefore, the development and application of qualified functional / structural integrated neutron / gamma ray shielding materials is extremely necessary.

[0003] Neutrons can be slowed down by inelastic collisions with atoms with high atomic numbers and elastic collisions with atoms with low atomic numbers, and then absorbed by elements with high absorption cross sections such as boron. Gamma rays can be effectively attenuated by interactions with atoms with high atomic numbers. At present, common neutron shielding materials include boron-containing steel, boron-containing aluminum composite materials, boron-containing polymer materials, etc. Considering the balance between structural and shielding properties, boron-containing steel and boron-containing aluminum composite materials are relatively mature neutron shielding materials. However, the amount of boron added to boron-containing steel is limited. If the ideal neutron absorption effect is to be achieved, the material thickness will be too large and the material brittleness will increase; boron-containing aluminum composite materials can be added with a higher content of boron, but their shielding effect on gamma rays is very poor, and the toughness is reduced, which limits their application in some nuclear facilities. Summary of the invention

[0004] In order to solve the compromise between the mechanical properties and neutron shielding properties of aluminum-based boron carbide shielding materials and the poor gamma-ray shielding ability of aluminum-based boron carbide materials, the main purpose of the present invention is to provide an aluminum-based composite material with high mechanical properties for neutron and gamma-ray shielding, which is a tungsten-boron-gadolinium-aluminum composite material with moderate density and neutron and gamma-ray shielding properties that has both functionality and structure.

[0005] Another object of the present invention is to provide a method for preparing the aluminum-based composite material with high mechanical properties for neutron and gamma ray shielding, which is prepared by a hot pressing process.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] The invention provides an aluminum-based composite material with high mechanical properties for neutron and gamma ray shielding, which is a tungsten-boron-gadolinium-aluminum composite material, which is prepared by taking a 6 series aluminum alloy as a basic alloy and adding tungsten boride with a volume fraction of 9% to 20%, or a mixed powder of tungsten and boron with a total volume fraction of 9% to 20%, and gadolinium oxide with a volume fraction of 1% to 4%.

[0008] Preferably, the density of the tungsten-boron-gadolinium-aluminum composite material is 4-5 g / cm 3 .

[0009] Preferably, the gadolinium oxide is gadolinium oxide ceramic particles.

[0010] In the above-mentioned tungsten-boron-gadolinium-aluminum composite material of the present invention, the aluminum alloy ensures the toughness of the material, the tungsten element can shield neutrons and gamma rays at the same time, and the boron ( 10 B) Elements and Gadolinium ( 157 Gd) element, can achieve efficient neutron absorption. Moreover, due to 157 The thermal neutron absorption cross section of Gd is much higher than 10 B (37 times), can effectively improve the mechanical properties of the composite material by reducing the content of boride without changing the neutron absorption performance; ceramic particles such as tungsten boride also enhance the strength of the material, achieving a good balance between the structure and functionality of the composite material; on the other hand, the addition of Gd2O3 forms Gd6W4Al 43 Inhibit hardening phase WAl 12 The coarsened network is formed, thereby greatly increasing the thermal neutron shielding ability and significantly improving the ductility of the composite material. In addition, the content of each component in the tungsten-boron-gadolinium-aluminum composite material can be adjusted according to the use requirements. The manufacturing and processing is flexible and convenient, non-toxic and harmless, and easy to promote.

[0011] The present invention also provides a method for preparing the aluminum-based composite material with high mechanical properties for neutron and gamma ray shielding, which is prepared by a hot pressing process and comprises the following steps:

[0012] Step 1, weighing tungsten boride, or a mixed powder of tungsten and boron, gadolinium oxide and aluminum alloy powder according to the designed composition ratio, placing them in a stainless steel tank, and adding ball milling media and lubricant to obtain the original ingredients;

[0013] Step 2, placing the stainless steel tank containing the original ingredients on a ball mill, and performing vacuum ball milling according to a predetermined program to obtain a mixed material;

[0014] Step 3: Load the mixture into a graphite mold, heat and pressurize at a predetermined heating rate and pressure rate in a vacuum environment or a protective atmosphere, and after reaching a predetermined sintering temperature and a predetermined pressure, perform hot pressing sintering under heat and pressure preservation conditions, cool to room temperature, and obtain a sintered block.

[0015] In the above preparation method of the present invention, tungsten, boron and gadolinium elements are introduced into the aluminum alloy powder to achieve simultaneous shielding of neutrons and gamma rays. First, the raw materials of each component are weighed according to a predetermined ratio, and a ball milling medium and a lubricant are added, and then intermittent ball milling is performed under vacuum conditions to obtain a mixture, wherein stearic acid is used as a lubricant to avoid the occurrence of cold welding of the aluminum alloy powder during long-term ball milling, which is conducive to the full mixing of the raw materials; intermittent ball milling under a vacuum environment avoids oxidation of the raw materials, which is conducive to sintering.

[0016] Preferably, in step 1, the volume fraction of tungsten boride used is 9% to 20%, or a mixed powder of tungsten and boron is used, and the sum of the volume fractions is 9% to 20%, the volume fraction of gadolinium oxide is 1% to 4%, and the remainder is aluminum alloy powder; stearic acid is used as a lubricant, and the addition amount is 0.5 to 1wt%. By forming a liquid film on the surface of the particles, the powders are prevented from sticking to each other during ball milling, which is conducive to uniform mixing of the powders.

[0017] Preferably, in step 1, the ball milling medium is any one of agate balls, stainless steel balls and zirconia balls, and the ball-to-material mass ratio is 1 to 3: 1. The function of the ball milling medium is to crush the ceramic particles and the mixed powder, and the destruction of the oxide layer on the particle surface and the uniform mixing of the powder are conducive to the sintering and densification of the material.

[0018] Preferably, in step 2, the ball milling procedure is: intermittently mixing and grinding the raw ingredients obtained in step 1 for 8 to 16 hours using a planetary ball mill at a grinding speed of 200 to 300 r / min, and the grinding time and intermittent time ratio of the intermittent grinding are 1 to 3: 1. Intermittent mixing and grinding effectively avoids overheating of the powder during the grinding process and oxidation, which is conducive to the densification of the final sintered block.

[0019] Preferably, in step 3, the vacuum degree of the vacuum environment is less than 2×10 -2 Pa, if it is a protective atmosphere, it is generally argon. Vacuum sintering or argon atmosphere sintering can avoid oxidation of the mixture and generate other oxidized impurities that affect the performance of the aluminum alloy.

[0020] Preferably, in step 3, the specific process of hot pressing sintering is: after heating to 200-400°C at a predetermined heating rate of 10-30°C / min, pressurizing is started at a predetermined pressurizing rate of 0.5-2MPa / min, and the temperature is continuously raised to 500-600°C at a predetermined heating rate of 5-10°C / min, and then kept warm for 1-3h at a pressure of 20-30MPa. First, the temperature is quickly raised to 200-400°C to promote the volatilization of stearic acid, and then heating and pressurizing and keeping warm and pressurizing promote the formation of effective connection between powders, which is conducive to the densification of sintered blocks.

[0021] Preferably, in step 3, the cooling treatment is temperature-controlled cooling and / or natural cooling, and the specific process is: when the temperature is higher than 300°C, temperature-controlled cooling is performed at a cooling rate of 5 to 10°C / min, and when the temperature is lower than 300°C, natural cooling is performed. Temperature-controlled cooling is performed in the high-temperature stage, and the sintered block is cooled at a lower rate, which is conducive to densification; natural cooling is then performed to shorten the sintering time and improve production efficiency.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The tungsten-boron-gadolinium-aluminum composite material of the present invention greatly improves the neutron shielding performance by adding gadolinium element with extremely high neutron absorption cross section, and can achieve good neutron and gamma ray shielding at the same time by controlling the ratio of tungsten and boron.

[0024] 2. The tungsten-boron-gadolinium-aluminum composite material of the present invention not only has good shielding performance, but also has considerable ductility and mechanical strength compared to common shielding materials. It has broad development space for application as a functional / structural material.

[0025] 3. The present invention can adjust the proportion of each functional component of the tungsten-boron-gadolinium-aluminum composite material according to specific application requirements to achieve functional / structural requirements under different conditions.

[0026] 4. The tungsten-boron-gadolinium-aluminum composite material of the present invention has a simple preparation process, low sintering temperature and pressure, is non-toxic and harmless, is easy to process, has a low manufacturing cost, and has great application value.

[0027] 5. The tungsten-boron-gadolinium-aluminum composite material of the present invention can simultaneously achieve good neutron and gamma-ray shielding, and the hardening phase WAl can be inhibited by adding a trace amount of gadolinium oxide. 12 The formation of a coarsened network greatly increases the thermal neutron shielding capability and has great application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The figure is a flow chart of the preparation process of the tungsten-boron-gadolinium-aluminum composite material of the present invention.

[0029] Figure 2 The figure shows the relationship between the thickness of the tungsten-boron-gadolinium-aluminum composite material of Example 1 and its neutron shielding performance.

[0030] Figure 3 The figure shows the relationship between the thickness of the tungsten boron gadolinium aluminum composite material of Example 1 and its photon shielding performance.

[0031] Figure 4 This is the phase measurement of the tungsten boron gadolinium aluminum composite material of Example 1.

[0032] Figure 5 This is the stress-strain curve of the bending test of the tungsten-boron-gadolinium-aluminum composite material of Example 1.

[0033] Figure 6 This is the stress-strain curve of the tensile test of the tungsten-boron-gadolinium-aluminum composite material of Example 1.

[0034] Figure 7 This is a scanning electron microscope image of the tungsten boron gadolinium aluminum composite material of Example 1. DETAILED DESCRIPTION

[0035] In order to more fully understand and demonstrate the technical solutions, purposes and advantages of the present invention, the technical effects produced by the present invention are further described in detail and completely in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all. It should be pointed out that for ordinary technicians in this field, other embodiments obtained without departing from the concept of the present invention all belong to the protection scope of the present invention.

[0036] like Figure 1 As shown, the preparation process of the tungsten-boron-gadolinium-aluminum composite material of Examples 1 to 6 is as follows: tungsten boride (or tungsten and boron) powder, gadolinium oxide powder and 6 series aluminum alloy powder are mixed, and lubricant and ball milling medium are added and intermittent ball milling is performed for 8 to 16 hours, and the ratio of the grinding time and the intermittent time of the intermittent ball milling is 1 to 3:1. The mixed material obtained after ball milling is loaded into a graphite mold, and then hot-pressed and sintered to obtain a tungsten-boron-gadolinium-aluminum composite material block.

[0037] <Example 1>

[0038] The tungsten-boron-gadolinium-aluminum composite material of this embodiment is prepared from the following raw materials in volume percentage: 13% tungsten boride, 2% gadolinium oxide, and the remainder is aluminum alloy, and the sintering temperature is 550°C.

[0039] The preparation method of the tungsten-boron-gadolinium-aluminum composite material of this embodiment is as follows:

[0040] Step 1: Weigh 24.58g of tungsten boride, 1.87g of gadolinium oxide and 28.55g of aluminum alloy powder, and add 1wt% of stearic acid as a lubricant. Zirconia ceramic balls are used as ball milling media, and the mass ratio of ceramic balls to raw materials is 3:1.

[0041] Step 2: Under vacuum conditions, the raw material obtained in step 1 is intermittently ball-milled at a speed of 250 r / min using a planetary ball mill for 16 h, with the ratio of ball-milling time to intermittent time being 3:1.

[0042] Step 3. Under vacuum conditions, the mixture obtained in step 2 is loaded into a graphite mold, followed by hot pressing and sintering. The specific process is: first, the temperature is raised to 400°C at 30°C / min under vacuum conditions, and then the pressure is increased to 25MPa at 1.67MPa / min, and at the same time, the temperature is raised to 550°C at 10°C / min, and sintered at 550°C and 25MPa for 2h, and then the temperature is lowered to 300°C at 6°C / min, and finally naturally cooled to room temperature.

[0043] Figure 2 : is the relationship curve between the thickness and neutron shielding performance of the tungsten-boron-gadolinium-aluminum composite material of this embodiment, wherein the neutron energy is 0.042eV. Figure 2 It can be seen that when the material thickness is 0.12cm, the neutron transmittance is only 1%, indicating that a 0.12cm thick tungsten boron gadolinium aluminum composite material can shield 99% of neutrons. This extremely efficient neutron shielding performance makes the material have great application potential in solving the problem of miniaturization and lightweight of shielding materials.

[0044] Figure 3 : is the relationship curve between the thickness of the tungsten-boron-gadolinium-aluminum composite material of this embodiment and the gamma-ray shielding performance, wherein the gamma-ray energy is 1.33 MeV. Figure 3 It can be seen that the 10.5 cm thick composite material can shield 99% of 1.33 MeV gamma rays.

[0045] Figure 4 This is the phase detection result of the tungsten-boron-gadolinium-aluminum composite material of this embodiment. The main phases are WB and Al, Gd6W4Al 43 It is the product of interfacial reaction.

[0046] The tungsten-boron-gadolinium-aluminum composite material of this embodiment has not only good neutron and gamma ray shielding performance, but also considerable mechanical properties. Its bending stress-strain curve is as follows: Figure 5 As shown, from Figure 5 It can be seen that the ultimate bending strength of the composite material is about 570MPa and has a fracture strain value of 4.5%.

[0047] Figure 6 This is the tensile test result of the tungsten-boron rolled aluminum composite material of this embodiment. The ultimate tensile strength is 297 MPa and the fracture strain is 6.7%, indicating that it has good processing properties.

[0048] Figure 7 This is a scanning electron microscope image of the tungsten-boron-gadolinium-aluminum composite material of this embodiment. It can be seen that the bright tungsten boride particles are evenly distributed in the black aluminum matrix.

[0049] <Example 2>

[0050] The tungsten-boron-gadolinium-aluminum composite material of this embodiment is prepared from the following raw materials in volume percentage: 13% tungsten boride, 2% gadolinium oxide, and the balance is aluminum, and the sintering temperature is 570°C.

[0051] The preparation method of the tungsten-boron-gadolinium-aluminum composite material of this embodiment is as follows:

[0052] Step 1: Weigh 24.58g of tungsten boride, 1.87g of gadolinium oxide and 28.55g of aluminum alloy powder, and add 0.8wt% of stearic acid as a lubricant. Stainless steel balls are used as ball milling media, and the mass ratio of stainless steel to raw materials is 3:1.

[0053] Step 2: Under vacuum conditions, the raw material obtained in step 1 is intermittently ball-milled at a speed of 250 r / min using a planetary ball mill for 13 h, with the ratio of ball-milling time to intermittent time being 3:1.

[0054] Step 3. Under vacuum conditions, the mixture obtained in step 2 is loaded into a graphite mold, followed by hot pressing and sintering. The specific process is: first, the temperature is raised to 300°C at 20°C / min under vacuum conditions, and then the pressure is increased to 28MPa at 1.03MPa / min, and at the same time, the temperature is raised to 570°C at 10°C / min, and sintered at 570°C and 28MPa for 2h, and then the temperature is lowered to 300°C at 6°C / min, and finally naturally cooled to room temperature.

[0055] The ultimate bending strength of the tungsten-boron-gadolinium-aluminum composite material of this embodiment is 525 MPa, and the fracture strain is 1.9%.

[0056] <Example 3>

[0057] The tungsten-boron-gadolinium-aluminum composite material of this embodiment is prepared from the following raw materials in volume percentage: 18% tungsten boride, 1.5% gadolinium oxide, and the balance is aluminum, and the sintering temperature is 570°C.

[0058] The preparation method of the tungsten-boron-gadolinium-aluminum composite material of this embodiment is as follows:

[0059] Step 1: Weigh 32.73 g of tungsten boride, 1.27 g of gadolinium oxide and 26 g of aluminum alloy powder, and add 1 wt% of stearic acid as a lubricant. The ball milling medium is zirconia ceramic balls, and the mass ratio of ceramic balls to raw materials is 2:1.

[0060] Step 2: Under vacuum conditions, the raw material obtained in step 1 is intermittently ball-milled at a speed of 250 r / min using a planetary ball mill for 13 h, with the ratio of ball-milling time to intermittent time being 3:1.

[0061] Step 3. Under vacuum conditions, the mixture obtained in step 2 is loaded into a graphite mold, followed by hot pressing and sintering. The specific process is: first, the temperature is raised to 200°C at 10°C / min under vacuum conditions, and then the pressure is increased to 25MPa at 0.67MPa / min, and at the same time, the temperature is raised to 570°C at 10°C / min, and sintered at 570°C and 25MPa for 2h, and then the temperature is lowered to 300°C at 6°C / min, and finally naturally cooled to room temperature.

[0062] The tungsten-boron-gadolinium-aluminum composite material of this embodiment has a bending strength of 563 MPa and a fracture strain of 1.3%.

[0063] <Example 4>

[0064] The tungsten-boron-gadolinium-aluminum composite material of this embodiment is prepared from the following raw materials in volume percentage: 9.5% tungsten, 4.2% boron, 2% gadolinium oxide, and the balance is aluminum, and the sintering temperature is 570°C.

[0065] The preparation method of the tungsten-boron-gadolinium-aluminum composite material of this embodiment comprises the following steps:

[0066] Step 1: Weigh 25.32g of tungsten, 1.5g of boron, 2.04g of gadolinium oxide and 31.15g of aluminum alloy powder, and add 1wt% of stearic acid as a lubricant. The ball milling medium is agate balls, and the mass ratio of agate balls to raw materials is 1:1.

[0067] Step 2: Under vacuum conditions, the raw material obtained in step 1 is intermittently ball-milled at a speed of 300 r / min using a planetary ball mill for 12 h, with the ratio of ball-milling time to intermittent time being 3:1.

[0068] Step 3. Under vacuum conditions, the mixture obtained in step 2 is loaded into a graphite mold, followed by hot pressing and sintering. The specific process is: first, the temperature is raised to 400°C at 20°C / min under vacuum conditions, and then the pressure is increased to 30MPa at 0.88MPa / min, and at the same time, the temperature is raised to 570°C at 5°C / min, and sintered at 570°C and 30MPa for 1h, and then the temperature is lowered to 300°C at 6°C / min, and finally naturally cooled to room temperature.

[0069] The tungsten-boron-gadolinium-aluminum composite material of this embodiment has a bending strength of 587 MPa and a fracture strain of 2.1%.

[0070] <Example 5>

[0071] The tungsten-boron-gadolinium-aluminum composite material of this embodiment is prepared from the following raw materials in volume percentage: 14% tungsten, 6% boron, 2% gadolinium oxide, and the balance is aluminum, and the sintering temperature is 570°C.

[0072] The preparation method of the tungsten-boron-gadolinium-aluminum composite material of this embodiment comprises the following steps:

[0073] Step 1: Weigh 31.68g of tungsten, 1.86g of boron, 1.74g of gadolinium oxide and 24.72g of aluminum alloy powder, and add 0.8wt% of stearic acid as a lubricant. The ball milling medium uses zirconium oxide ceramic balls, and the mass ratio of ceramic balls to raw materials is 2:1.

[0074] Step 2: Under vacuum conditions, the raw material obtained in step 1 is intermittently ball-milled at a speed of 250 r / min using a planetary ball mill for 16 h, with the ratio of ball-milling time to intermittent time being 3:1.

[0075] Step 3. Under vacuum conditions, the mixture obtained in step 2 is loaded into a graphite mold, followed by hot pressing and sintering. The specific process is: first, the temperature is raised to 300°C at 15°C / min under vacuum conditions, and then the pressure is increased to 25MPa at 0.92MPa / min, and at the same time, the temperature is raised to 570°C at 10°C / min, and sintered at 570°C and 25MPa for 1h, and then the temperature is lowered to 300°C at 6°C / min, and finally naturally cooled to room temperature.

[0076] The tungsten-boron-gadolinium-aluminum composite material of this embodiment has a bending strength of 624 MPa and a fracture strain of 0.8%.

[0077] <Example 6>

[0078] The tungsten-boron-gadolinium-aluminum composite material of this embodiment is prepared from the following raw materials in volume percentage: 12% tungsten, 5% boron, 3% gadolinium oxide, and the balance is aluminum, and the sintering temperature is 590°C.

[0079] The preparation method of the tungsten-boron-gadolinium-aluminum composite material of this embodiment comprises the following steps:

[0080] Step 1: Weigh 27.42g of tungsten, 1.54g of boron, 2.51g of gadolinium oxide and 25.54g of aluminum alloy powder, and add 0.7wt% of stearic acid as a lubricant. Stainless steel balls are used as ball milling media, and the mass ratio of stainless steel balls to raw materials is 3:1.

[0081] Step 2: Under vacuum conditions, the raw material obtained in step 1 is intermittently ball-milled at a speed of 250 r / min using a planetary ball mill for 16 h, with the ratio of ball-milling time to intermittent time being 3:1.

[0082] Step 3. Under vacuum conditions, the mixture obtained in step 2 is loaded into a graphite mold, followed by hot pressing and sintering. The specific process is: first, the temperature is raised to 400°C at 30°C / min under vacuum conditions, and then the pressure is increased to 25MPa at 1.31MPa / min, and at the same time, the temperature is raised to 590°C at 10°C / min, and sintered at 590°C and 25MPa for 1h, and then the temperature is lowered to 300°C at 6°C / min, and finally naturally cooled to room temperature.

[0083] The tungsten-boron-gadolinium-aluminum composite material of this embodiment has a bending strength of 614 MPa and a fracture strain of 1.1%.

[0084] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high mechanical performance aluminum-based composite material for neutron and gamma ray shielding, characterized in that: The invention relates to a tungsten-boron-gadolinium-aluminum composite material, which is prepared by taking a 6 series aluminum alloy as a basic alloy and adding 9% to 20% by volume tungsten boride, or a mixed powder of tungsten and boron with a sum of 9% to 20% by volume, and 1% to 4% by volume gadolinium oxide.

2. The aluminum-based composite material with high mechanical properties for neutron and gamma ray shielding according to claim 1, characterized in that: The density of the tungsten-boron-gadolinium-aluminum composite material is 4-5 g / cm 3 .

3. The aluminum-based composite material with high mechanical properties for neutron and gamma ray shielding according to claim 1, characterized in that: The gadolinium oxide is gadolinium oxide ceramic particles.

4. The method for preparing the aluminum-based composite material with high mechanical properties for neutron and gamma ray shielding according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1, weighing tungsten boride, or a mixed powder of tungsten and boron, gadolinium oxide and aluminum alloy powder according to the designed composition ratio, placing them in a stainless steel tank, and adding ball milling media and lubricant to obtain the original ingredients; Step 2, placing the stainless steel tank containing the original ingredients on a ball mill, and performing vacuum ball milling according to a predetermined program to obtain a mixed material; Step 3: Load the mixture into a graphite mold, heat and pressurize at a predetermined heating rate and pressure rate in a vacuum environment or a protective atmosphere, and after reaching a predetermined sintering temperature and a predetermined pressure, perform hot pressing sintering under heat and pressure preservation conditions, cool to room temperature, and obtain a sintered block.

5. The method for preparing the aluminum-based composite material with high mechanical properties for neutron and gamma ray shielding according to claim 4, characterized in that: In step 1, the volume fraction of the tungsten boride is 9% to 20%, or the sum of the volume fractions of the mixed powder of tungsten and boron is 9% to 20%, the volume fraction of gadolinium oxide is 1% to 4%, and the remainder is aluminum alloy powder; and / or the lubricant is stearic acid, and the addition amount is 0.5 to 1wt%.

6. The method for preparing the aluminum-based composite material with high mechanical properties for neutron and gamma ray shielding according to claim 4, characterized in that: In step 1, the ball milling medium is selected from one of agate balls, stainless steel balls and zirconia balls, and the ball-to-material mass ratio is 1 to 3:

1.

7. The method for preparing the aluminum-based composite material with high mechanical properties for neutron and gamma ray shielding according to claim 4, characterized in that: In step 2, the ball milling procedure is: using a planetary ball mill to intermittently mix and grind the original ingredients at a grinding speed of 200 to 300 r / min for 8 to 16 hours, and the ratio of the grinding time to the intermittent time of the intermittent mixing and grinding is 1 to 3:

1.

8. The method for preparing the aluminum-based composite material with high mechanical properties for neutron and gamma ray shielding according to claim 4, characterized in that: In step 3, the vacuum degree of the vacuum environment is less than 2×10 -2 Pa, the protective atmosphere is argon.

9. The method for preparing the aluminum-based composite material with high mechanical properties for neutron and gamma ray shielding according to claim 4, characterized in that: In step 3, the hot pressing sintering process is: heating to 200-400°C at a predetermined heating rate of 10-30°C / min, starting pressurization at a predetermined pressurization rate of 0.5-2MPa / min, and continuing to heat to 500-600°C at a predetermined heating rate of 5-10°C / min, and then keeping warm at a pressure of 20-30MPa for 1-3h.

10. The method for preparing the aluminum-based composite material with high mechanical properties for neutron and gamma ray shielding according to claim 4, characterized in that: In step 3, the cooling treatment is temperature-controlled cooling and / or natural cooling. When the temperature is higher than 300°C, temperature-controlled cooling is performed at a cooling rate of 5 to 10°C / min. When the temperature is lower than 300°C, natural cooling is performed.

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