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CN-122012971-A - Method for strengthening NiAl-based composite material through multi-scale bimodal structure

CN122012971ACN 122012971 ACN122012971 ACN 122012971ACN-122012971-A

Abstract

A method for strengthening a NiAl-based composite material through a multi-scale bimodal structure relates to a preparation method of a nickel-aluminum composite material. The invention aims to solve the problem that the existing method is difficult to consider the low density, room temperature plasticity and high temperature strength of NiAl, thereby seriously impeding the application process. The method comprises the steps of weighing Ni, al, V, mo, zr and B powder, carrying out ball milling in stages, screening out mixed metal powder with two different particle sizes, mixing the mixed metal powder with the two different particle sizes, applying precompression, heating, and cooling along with a furnace. According to the invention, two mixed metal powder particles with different particle diameters are mixed, a structure with continuous and staggered double-peak tissues is obtained by utilizing a classical sintering theory at high temperature, and meanwhile, V (Mo) phases and ceramic particles are respectively distributed in a material matrix and at a grain boundary, so that the toughness of the material can be improved while the low density of the material is maintained.

Inventors

  • ZHAO WENHUI
  • LU ZHEN
  • WANG TIANBO

Assignees

  • 哈尔滨工业大学

Dates

Publication Date
20260512
Application Date
20260306

Claims (10)

  1. 1. A method for reinforcing a NiAl-based composite material by a multi-scale bimodal structure, characterized in that the method is performed according to the following steps: 1. weighing Ni, al, V, mo, zr and B powder in a vacuum glove box, and uniformly mixing to obtain mixed metal powder; 2. the ball milling tank is vacuumized, then high-purity argon is introduced, the operation is repeated, and the ball milling tank is sealed, the sealed ball milling tank is put on a ball mill, ball milling is carried out for 2-3 hours at 300-350 r/min, ball milling is carried out for 1.5-3 hours at 550-650 r/min, finally quantitative oxygen is introduced into the tank after the ball milling tank is vacuumized again, ball milling is carried out for 5-6 hours at 450-500 r/min, mixed metal powder with the particle size of 100 mu m is screened out, the rest mixed metal powder is continuously ball milled for 1-3 hours, and mixed metal powder with the particle size of 30 mu m is screened out; 3. mixing mixed metal powder with the particle size of 100 mu m and mixed metal powder with the particle size of 30 mu m in a ball milling tank at a low speed to obtain two uniformly mixed powder with the particle size; The mass ratio of the mixed metal powder with the particle size of 100 mu m to the mixed metal powder with the particle size of 30 mu m in the third step is (40-60) (60-40); 4. Transferring the powder with the two uniformly mixed particle sizes into a high-strength graphite mold, placing the high-strength graphite mold into a vacuum hot-pressing sintering furnace, applying pre-pressing force through a pressing head, maintaining pressure, decompressing after compacting the powder, and vacuumizing; 5. Heating the die at a certain heating rate after the vacuum degree reaches a certain value, and keeping the temperature for a period of time after the temperature is raised to 1400 ℃, wherein pressure is continuously applied in the heat preservation process; 6. stopping heating after heat preservation, cooling along with a furnace, releasing pressure when the temperature is reduced to 800 ℃, closing a diffusion pump when the temperature is reduced to below 400 ℃, naturally cooling to below 80 ℃, and taking out the high-strength graphite mold to obtain the NiAl-based composite material with multi-scale and bimodal structure reinforcement.
  2. 2. The method for reinforcing a NiAl-based composite material with a multi-scale bimodal structure according to claim 1, wherein the mass ratio of Ni, al, V, mo, zr to B powder in the first step is (5.753-6.166): (2.699-2.888): (0-0.6): (0-0.4): 0.296:0.1.
  3. 3. The method for reinforcing a NiAl-based composite material by a multi-scale bimodal structure according to claim 1, wherein the mass ratio of the grinding balls to the mixed metal powder in the first step is (10-12): 1.
  4. 4. The method for preparing the NiAl-based composite material reinforced by the multi-scale bimodal structure according to claim 1, wherein the Ni powder in the first step has a particle size of 5-20 μm and a purity of more than 99.5%, and the Al powder in the first step has a particle size of 5-50 μm and a purity of more than 99.9%.
  5. 5. The method for reinforcing a NiAl-based composite material by a multi-scale bimodal structure according to claim 1, wherein the particle size of the V powder in the step I is 5-50 μm, the purity is more than 99.9%, the particle size of the Mo powder in the step I is 10-50 μm, the purity is more than 99.9%, the particle size of the Zr powder in the step I is 5-50 μm, the purity is more than 99.9%, and the particle size of the B powder in the step I is 10-50 μm, and the purity is more than 99.9%.
  6. 6. The method for reinforcing a NiAl-based composite material by a multi-scale bimodal structure according to claim 1, wherein the grinding balls in the first step are one or two of 8mm and 6mm in diameter, and the ball milling tank in the first step is made of stainless steel and has a volume of 250-500 mL.
  7. 7. The method for reinforcing the NiAl-based composite material through the multi-scale bimodal structure according to claim 1, wherein the number of repeated operations in the second step is 3-5, each ball milling is performed for 10-20 min in the ball milling process in the second step, 2-5 min is cooled, and the mass ratio of the volume of oxygen to the mixed metal powder is (100-110 mL) (9.5-10 g).
  8. 8. The method for reinforcing a NiAl-based composite material with a multi-scale bimodal structure according to claim 1, wherein the low-rate mixing in the third step is ball milling for 2-3 hours at 300-350 r/min.
  9. 9. The method for reinforcing a NiAl-based composite material through a multi-scale and bimodal structure according to claim 1, wherein the flexural strength of the high-strength graphite mold in the fourth step is greater than 60MPa, the pre-compression force applied in the fourth step is 5-10 MPa, and the pressure maintaining time is 30-60min.
  10. 10. The method for reinforcing a NiAl-based composite material through a multi-scale bimodal structure according to claim 1, wherein in the fifth step, after the vacuum degree reaches 1X 10 -4 MPa, a mold is heated at a temperature rising rate of 15-30 ℃ per minute, after the temperature is raised to 1400 ℃, the mold is kept for 30-60 minutes, and a pressure of 40-50 MPa is continuously applied in the heat preservation process.

Description

Method for strengthening NiAl-based composite material through multi-scale bimodal structure Technical Field The invention relates to a preparation method of a nickel-aluminum composite material. Background The NiAl intermetallic compound is considered as one of high-temperature structural materials with great potential because of high melting point (1638 ℃), low density (5.86 g/cm 3), excellent high-temperature oxidation resistance and good heat conductivity, and has important application prospect in the fields of aeroengine blades, turbine discs, heat protection systems and the like. However, the existing research is difficult to combine the low density, room temperature plasticity and high temperature strength of the material, and the engineering application of the material is severely limited. In order to solve the above problems, in recent years, various methods such as alloying and second phase dispersion strengthening have been tried, and although the strength can be improved to some extent, it is often difficult to fundamentally solve the contradiction between strength and toughness at the expense of plasticity and density. In recent years, inspired by biological structures in the nature, the bimodal structural design provides a new idea for breaking through the performance bottleneck of the NiAl-based composite material. Research shows that the bimodal structural material can effectively inhibit crack growth, improve stress distribution and improve fracture toughness through multi-scale construction and interface optimization. Nevertheless, there is currently still little research on multi-scale bimodal structure reinforced NiAl-based composites. Disclosure of Invention The invention aims to solve the problem that the existing method is difficult to consider the low density, room temperature plasticity and high temperature strength of NiAl, so that the application process of the NiAl is seriously hindered, and provides a method for reinforcing a NiAl-based composite material through a multi-scale and bimodal structure. A method for strengthening a NiAl-based composite material through a multi-scale bimodal structure is completed according to the following steps: 1. weighing Ni, al, V, mo, zr and B powder in a vacuum glove box, and uniformly mixing to obtain mixed metal powder; 2. the ball milling tank is vacuumized, then high-purity argon is introduced, the operation is repeated, and the ball milling tank is sealed, the sealed ball milling tank is put on a ball mill, ball milling is carried out for 2-3 hours at 300-350 r/min, ball milling is carried out for 1.5-3 hours at 550-650 r/min, finally quantitative oxygen is introduced into the tank after the ball milling tank is vacuumized again, ball milling is carried out for 5-6 hours at 450-500 r/min, mixed metal powder with the particle size of 100 mu m is screened out, the rest mixed metal powder is continuously ball milled for 1-3 hours, and mixed metal powder with the particle size of 30 mu m is screened out; 3. mixing mixed metal powder with the particle size of 100 mu m and mixed metal powder with the particle size of 30 mu m in a ball milling tank at a low speed to obtain two uniformly mixed powder with the particle size; The mass ratio of the mixed metal powder with the particle size of 100 mu m to the mixed metal powder with the particle size of 30 mu m in the third step is (40-60) (60-40); 4. Transferring the powder with the two uniformly mixed particle sizes into a high-strength graphite mold, placing the high-strength graphite mold into a vacuum hot-pressing sintering furnace, applying pre-pressing force through a pressing head, maintaining pressure, decompressing after compacting the powder, and vacuumizing; 5. Heating the die at a certain heating rate after the vacuum degree reaches a certain value, and keeping the temperature for a period of time after the temperature is raised to 1400 ℃, wherein pressure is continuously applied in the heat preservation process; 6. stopping heating after heat preservation, cooling along with a furnace, releasing pressure when the temperature is reduced to 800 ℃, closing a diffusion pump when the temperature is reduced to below 400 ℃, naturally cooling to below 80 ℃, and taking out the high-strength graphite mold to obtain the NiAl-based composite material with multi-scale and bimodal structure reinforcement. The invention has the advantages that: 1. The invention discloses a method for strengthening a NiAl-based composite material through a multi-scale bimodal structure, which comprises the steps of obtaining two powder particles with uniform particle sizes through ball milling, obtaining a structure with continuous staggered distribution of a bimodal structure by utilizing a classical sintering theory at high temperature, and simultaneously, respectively distributing V (Mo) phases and ceramic particles in a material matrix and at a grain boundary, so that the toughness of the material can be improved w