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CN-121472617-B - GdB (Global positioning System) preparation based on molten salt method in-situ reaction2C2Method for producing an Al composite and composite

CN121472617BCN 121472617 BCN121472617 BCN 121472617BCN-121472617-B

Abstract

The invention belongs to the technical field of neutron shielding materials, and relates to a method for preparing a GdB 2 C 2 /Al composite material based on molten salt method in-situ reaction and a composite material, wherein the method comprises the following steps of S1, mixing B 4 C powder with graphite powder to obtain mixed powder, mixing the mixed powder with carbonate molten salt to obtain a premix, and heating the premix to be completely melted at a heating temperature of 900-1200 ℃ to obtain a first reaction melt; S2, adding aluminum gadolinium alloy into the first reaction melt at a constant temperature of 900-1200 ℃ for a first reaction to obtain a second reaction melt, adding pure aluminum into the second reaction melt for a second reaction to obtain a third reaction melt, S3, removing slag on the surface of the third reaction melt, and casting into a mold for molding to obtain the GdB 2 C 2 /Al composite material. The composite material has high neutron absorption efficiency and good mechanical property, and is suitable for the field of nuclear fuel storage and nuclear radiation protection.

Inventors

  • ZHOU XIAOBING
  • CUI PENGXING
  • SHI QIAN
  • QIN GANG
  • HE LIRUI
  • Tao Tiantian

Assignees

  • 宁波杭州湾新材料研究院
  • 中国科学院宁波材料技术与工程研究所

Dates

Publication Date
20260512
Application Date
20260112

Claims (6)

  1. 1. A method for preparing a GdB 2 C 2 /Al composite material based on molten salt method in-situ reaction, which is characterized by comprising the following steps: s1, mixing B 4 C powder with graphite powder to obtain mixed powder, mixing the mixed powder with carbonate molten salt to obtain premix, and heating the premix to be completely melted at a heating temperature of 900-1200 ℃ to obtain a first reaction melt; s2, adding aluminum-gadolinium alloy into the first reaction melt at a constant temperature of 900-1200 ℃ to perform a first reaction to obtain a second reaction melt, and adding pure aluminum into the second reaction melt to perform a second reaction to obtain a third reaction melt; S3, removing slag on the surface of the third reaction melt, and casting the slag into a mold for molding to obtain the GdB 2 C 2 /Al composite material; wherein the constant temperature in the step S2 is more than or equal to the heating temperature in the step S1; In the step S1, the mass ratio of the B 4 C powder to the graphite powder is 1 (0.5-3); in the step S1, the mass ratio of the mixed powder to the carbonate molten salt is 1 (2-5); in the step S2, the mass ratio of the first reaction melt to the Al-Gd alloy is 1 (1-10); in the step S2, the mass ratio of the second reaction melt to the pure aluminum is 1 (0.1-1); In the step S2, the first reaction process is mechanically stirred, the first reaction process is thermally insulated for 10-60 min, the second reaction process is mechanically stirred, the second reaction process is thermally insulated for 30-300 min.
  2. 2. The method for preparing a GdB 2 C 2 /Al composite material based on molten salt growth in-situ reaction according to claim 1, wherein in step S1, the carbonate molten salt comprises at least two of sodium carbonate, potassium carbonate and calcium carbonate.
  3. 3. The method for preparing the GdB 2 C 2 /Al composite material based on molten salt method in-situ reaction according to claim 1, wherein in the step S1, the heating temperature of the premix is 900-1000 ℃.
  4. 4. The method for preparing a GdB 2 C 2 /Al composite material based on molten salt process in situ reaction according to claim 1, wherein the method further comprises post-treatment, wherein the post-treatment comprises extrusion forming and/or rolling deformation; the extrusion ratio adopted in the extrusion molding is more than 10:1; The deformation amount is more than 30% during rolling deformation.
  5. 5. A GdB 2 C 2 /Al composite material, characterized in that it is prepared by the method for preparing a GdB 2 C 2 /Al composite material based on molten salt growth in situ reaction according to any one of claims 1 to 4.
  6. 6. The GdB 2 C 2 /Al composite of claim 5, wherein the GdB 2 C 2 /Al composite has a GdB 2 C 2 volume fraction of 0.1 to 15vol%.

Description

Method for preparing GdB 2C2/Al composite material based on molten salt method in-situ reaction and composite material Technical Field The invention belongs to the technical field of neutron shielding materials, and relates to a method for preparing a GdB 2C2/Al composite material based on molten salt method in-situ reaction and the composite material. Background With the widespread use of nuclear energy, the demand for efficient neutron shielding materials by spent fuel storage casks and storage grillwork is continually increasing. The ideal neutron shielding material not only needs to have a higher neutron absorption section, but also has excellent mechanical properties and lower density so as to meet the safety and reliability of nuclear energy equipment under long-term service conditions. The existing aluminum-based neutron shielding material is mainly represented by a B 4 C/Al composite material, and the existing aluminum-based neutron shielding material is mature in industrial application. However, only when the B 4 C content reaches above 30%, the composite material has good neutron shielding capability, which often results in significant reduction of plasticity and toughness, thus limiting engineering applications of the material. Meanwhile, the traditional B 4 C/Al composite material is mostly prepared by a powder metallurgy process, and the method has high energy consumption, limited yield and longer production period, and is not beneficial to large-scale application. In contrast, if the aluminum-based neutron shielding composite material is prepared by adopting an in-situ reaction smelting-casting process, the production efficiency can be obviously improved, the energy consumption and the preparation period can be reduced, the tight combination between the reinforcing phase and the matrix can be realized, and the comprehensive performance of the material can be further improved. However, in molten aluminum, the solubility of B 4 C and graphite (C) is extremely low, and it is difficult to sufficiently react with Gd element in al—gd alloy, limiting in-situ generation of high-efficiency neutron absorption phase GdB 2C2. In order to solve the problem, if a molten salt method can be introduced to improve the reactivity of B 4 C and C, promote the dissolution and diffusion of B and C elements and then react with Gd element in situ, the method is expected to realize the one-step rapid synthesis of the GdB 2C2 ceramic phase in an aluminum matrix. The method not only provides a feasible new way for preparing the high-efficiency neutron shielding composite material, but also provides important support for the safety guarantee of nuclear energy equipment. Disclosure of Invention The invention aims to solve the problems in the prior art, and provides a method for preparing a GdB 2C2/Al composite material based on molten salt method in-situ reaction, which solves the problems of low solubility and insufficient reaction of B 4 C and C in molten aluminum liquid and generates a uniformly distributed GdB 2C2 ceramic phase in situ in an aluminum matrix. One object of the invention is achieved by the following technical scheme: A method for preparing a GdB 2C2/Al composite material based on molten salt method in-situ reaction, which comprises the following steps: s1, mixing B 4 C powder with graphite powder to obtain mixed powder, mixing the mixed powder with carbonate molten salt to obtain premix, and heating the premix to be completely melted at a heating temperature of 900-1200 ℃ to obtain a first reaction melt; s2, adding aluminum-gadolinium alloy into the first reaction melt at a constant temperature of 900-1200 ℃ to perform a first reaction to obtain a second reaction melt, and adding pure aluminum into the second reaction melt to perform a second reaction to obtain a third reaction melt; S3, removing slag on the surface of the third reaction melt, and casting the slag into a die for molding to obtain the GdB 2C2/Al composite material. Preferably, in the step S1, the molten carbonate salt includes at least two of sodium carbonate, potassium carbonate and calcium carbonate. Further preferably, the carbonate molten salt is sodium carbonate and potassium carbonate with a mass ratio of 1 (0.1-10). Still more preferably, the carbonate molten salt is sodium carbonate and potassium carbonate with a mass ratio of 1:1. Preferably, in the step S1, the mass ratio of the B 4 C powder to the graphite powder is 1 (0.5 to 3). Further preferably, the mass ratio of the B 4 C powder to the graphite powder is 1 (1-2). Preferably, in the step S1, the mass ratio of the powder mixture to the carbonate molten salt is 1 (2-5). Further preferably, the mass ratio of the mixed powder to the carbonate molten salt is 1:3. Preferably, in the step S1, the heating temperature of the premix is 900-1000 ℃. Preferably, in the step S1, graphite stirring bars are used for stirring at a speed of 60-120 r/min for 1-5 min at intervals of 10-20 min