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CN-121974703-A - Magnesium aluminum boride-cubic boron nitride composite ceramic and preparation method thereof

CN121974703ACN 121974703 ACN121974703 ACN 121974703ACN-121974703-A

Abstract

The invention relates to a magnesium aluminum boride-cubic boron nitride composite ceramic and a preparation method thereof. The preparation method of the magnesium aluminum boride-cubic boron nitride composite ceramic comprises the steps of mixing AlMgB 14 powder with CBN powder to obtain ceramic slurry, drying and sieving the ceramic slurry to obtain ceramic powder, and sintering the ceramic powder to obtain the magnesium aluminum boride-cubic boron nitride composite ceramic. The preparation method of the magnesium aluminum boride-cubic boron nitride composite ceramic provided by the invention has the advantages of ultrahigh hardness, mass production and the like.

Inventors

  • ZHANG JINGXIAN
  • ZHANG KAIQING
  • TANG WENYU
  • LUO CHAOHUA
  • DUAN YUSEN

Assignees

  • 中国科学院上海硅酸盐研究所

Dates

Publication Date
20260505
Application Date
20260123

Claims (10)

  1. 1. A preparation method of the magnesium aluminum boride-cubic boron nitride composite ceramic is characterized by comprising the steps of mixing AlMgB 14 powder with CBN powder to obtain ceramic slurry, drying and sieving the ceramic slurry to obtain ceramic powder, and sintering the ceramic powder to obtain the magnesium aluminum boride-cubic boron nitride composite ceramic.
  2. 2. The preparation method of the AlMgB 14 powder is characterized by adopting aluminum powder, magnesium powder and boron powder as raw materials and preparing the AlMgB 14 powder through in-situ reaction, wherein the preparation method of the AlMgB 14 powder comprises the steps of dispersing the aluminum powder, the magnesium powder and the boron powder in ethanol, ball milling for 12-24 hours to obtain ceramic slurry, vacuum drying the ceramic slurry at 40-80 ℃ for 2-6 hours to obtain ceramic powder, sieving the ceramic powder, and then placing the ceramic powder into a boron nitride crucible for calcination to obtain AlMgB 14 powder; Preferably, the mass ratio of the aluminum powder to the magnesium powder to the boron powder is 1 (0.5-2): 4-6; Preferably, the calcination temperature is 900-1400 ℃, the heat preservation time is 1-4 h, and more preferably, the ambient atmosphere is argon.
  3. 3. The preparation method according to claim 1 or 2, wherein the AlMgB 14 powder has a purity of 95% or more and a particle size of 1 μm to 10 μm, and the CBN powder has a purity of 96% to 99% and a particle size of 0.1 to 1000 μm.
  4. 4. The preparation method of any one of claims 1-3, wherein the mass ratio of AlMgB 14 powder to CBN powder is (30-90) (10-70).
  5. 5. A preparation method of the magnesium aluminum boride-cubic boron nitride composite ceramic is characterized by comprising the steps of mixing aluminum powder, magnesium powder, boron powder and CBN powder to obtain ceramic slurry, drying and sieving the ceramic slurry to obtain ceramic powder, and sintering the ceramic powder to obtain the magnesium aluminum boride-cubic boron nitride composite ceramic.
  6. 6. The production method according to any one of claims 1 to 5, wherein the aluminum powder has a purity of more than 98%, a particle diameter of 0.1 to 20 μm, the magnesium powder has a purity of more than 98%, a particle diameter of 1 to 30 μm, and the boron powder has a purity of more than 98%, a particle diameter of 0.1 to 10 μm; preferably, the mass ratio of the total mass of the aluminum powder, the magnesium powder and the boron powder to the CBN powder is (30-90) (10-70); more preferably, the mass ratio of the aluminum powder to the magnesium powder to the boron powder is 1 (0.5-2): 4-6.
  7. 7. The preparation method of any one of claims 1-6, wherein the mixing mode is ball milling mixing, and the parameters of ball milling mixing comprise a ball milling rotating speed of 20-60 rpm, a ball milling time of 12-24 h and absolute ethyl alcohol as a solvent; the drying is vacuum drying, the drying temperature is 40-80 ℃, and the drying time is 2-6 hours.
  8. 8. The method of any one of claims 1-7, wherein the sintering comprises a first sintering process and a second sintering process; preferably, the first sintering process is hot-press sintering, wherein the parameters of the hot-press sintering comprise that the sintering temperature is 600-1600 ℃, the sintering pressure is 30-60 MPa, the heating rate is below 30 ℃ per minute, and the heat preservation time is 1-4 hours; Preferably, the second sintering process is hot isostatic pressing sintering, wherein the parameters of the hot isostatic pressing sintering comprise that the sintering temperature is 600-1600 ℃, the sintering pressure is 100-300 MPa, the heating rate is below 30 ℃ per minute, the heat preservation time is 1-4 hours, and more preferably, the protective atmosphere is high-purity argon atmosphere.
  9. 9. A magnesium aluminum boride-cubic boron nitride composite ceramic prepared according to the preparation method of any one of claims 1 to 8.
  10. 10. The magnesium aluminum boride-cubic boron nitride composite ceramic according to claim 9, wherein the hardness of the magnesium aluminum boride-cubic boron nitride composite ceramic is 30-40 gpa.

Description

Magnesium aluminum boride-cubic boron nitride composite ceramic and preparation method thereof Technical Field The invention belongs to the field of superhard material preparation, and relates to magnesium aluminum boride (AlMgB 14) -Cubic Boron Nitride (CBN) composite ceramic and a preparation method thereof. Background Superhard materials are key materials that are not an alternative to industrial and technological developments. Superhard materials are an important strategic reserve in many countries. Currently, superhard materials are mainly classified into diamond and cubic boron nitride (c-BN). However, the two materials have the advantages of extremely high hardness, better wear resistance and the like, and also have the problems of severe preparation conditions, high production cost, large pollution and the like. Therefore, the development of a novel superhard material which can meet the requirements of modern production on high hardness and good wear resistance and has the advantages of low friction coefficient, low density, low cost and the like is urgent. Since 2000, ames laboratories reported that AlMgB 14 ceramics (32-35 GPa) have extremely high hardness and wide application. The advantages of excellent wear resistance, high temperature stability, heat resistance, low density and the like are widely studied in the fields of cutting tools, armors, heat-resistant coatings and the like. In the study of improving the hardness, ahmed and the like adopt hot-pressed sintering to add TiB 2 into AlMgB 14 powder, and AlMgB 14 composite ceramic with the highest hardness of 36.8GPa is obtained. M. Herrmann adds TiC to AlMgB 14 powder and hot-pressed sinters, the hardness is about 33.8GPa at most. However, the further increase of the hardness encounters a bottleneck, and in order to increase the hardness to more than 40GPa, the requirements of cutting, armor and the like are met, and the method is still a test. Disclosure of Invention Aiming at the problems existing in the prior art, the invention provides the magnesium aluminum boride-cubic boron nitride composite ceramic and the preparation method thereof, and the hardness of the AlMgB 14 ceramic material is further improved by introducing CBN. According to the invention, one or more CBN powder with particle size is added into AlMgB 14 powder (purity is more than 95 wt%), and a sintering mode of combining hot pressing sintering and hot isostatic pressing sintering is adopted to obtain the high-hardness AlMgB 14 -CBN composite ceramic material. In a first aspect, the invention provides a preparation method of magnesium aluminum boride-cubic boron nitride composite ceramic, which comprises the steps of mixing AlMgB 14 powder with CBN powder to obtain ceramic slurry, drying and sieving the ceramic slurry to obtain ceramic powder, and sintering the ceramic powder to obtain the magnesium aluminum boride-cubic boron nitride composite ceramic. The AlMgB 14 powder is prepared by in-situ reaction by using aluminum powder, magnesium powder and boron powder as raw materials, wherein the preparation method of the AlMgB 14 powder comprises the steps of dispersing the aluminum powder, the magnesium powder and the boron powder in ethanol, ball milling for 12-24 hours to obtain ceramic slurry, vacuum drying the ceramic slurry at 40-80 ℃ for 2-6 hours to obtain ceramic powder, sieving the ceramic powder with a 100-mesh sieve, and calcining in a boron nitride crucible to obtain AlMgB 14 powder. Preferably, the mass ratio of the aluminum powder to the magnesium powder to the boron powder is 1 (0.5-2): 4-6. Preferably, the calcination temperature is 900-1400 ℃, the heat preservation time is 1-4 h, and preferably, the ambient atmosphere is argon. Preferably, the purity of the AlMgB 14 powder is more than 95%, the particle size is 1-10 mu m, the purity of the CBN powder is 96-99.9%, and the particle size is 0.1-1000 mu m. Preferably, the mass ratio of the AlMgB 14 powder to the CBN powder is (30-90) (10-70). Preferably, the mixing mode is ball milling mixing, and the parameters of the ball milling mixing comprise the ball milling rotating speed of 20-60 rpm and the ball milling time of 12-24 hours, and absolute ethyl alcohol is used as a solvent. Preferably, the drying is vacuum drying, the drying temperature is 40-80 ℃, and the drying time is 2-6 hours. The invention provides a preparation method of magnesium aluminum boride-cubic boron nitride composite ceramic, which comprises the steps of mixing aluminum powder, magnesium powder, boron powder and CBN powder to obtain ceramic slurry, drying and sieving the ceramic slurry to obtain ceramic powder, and sintering the ceramic powder to obtain the magnesium aluminum boride-cubic boron nitride composite ceramic. Preferably, the purity of the aluminum powder is more than 98%, the grain size is 0.1-20 mu m, the purity of the magnesium powder is more than 98%, the grain size is 1-30 mu m, the purity of the boron powder is more than 9