Research progress on high grade aluminum nitride powder and its carbothermal reduction-nitridation preparation

Aluminum nitride (AlN) has high thermal conductivity, good insulation, low thermal expansion coefficient, non-magnetic, and other excellent properties used as a key material for high-end equipment in semiconductor, electric vacuum, and other fields. Especially in aerospace, rail transportation, new energy equipment, high-power LED, 5G communication, power transmission, industrial control, and other fields of power devices, AlN has an irreplaceable role. The high-grade powders are the basis for the preparation of high-performance ceramics. The properties of AlN powders directly affect the forming, sintering, microstructure, and performance of the AlN ceramics. Carbothermal reduction-nitridation method is a promising method to produce the AlN powders with high purity, fine particle size, and high sintering property. The evaluation indexes of the AlN powders and the research progress on the carbothermal reduction-nitridation of AlN powders were reviewed in this paper, and the direction and trend of future research and industrialization were proposed.