METHOD FOR PREPARING ALUMINUM NITRIDE POWDER BY SELF-PROPAGATING HIGH TEMPERATURE SYNTHESIS

摘要

PURPOSE: A method for preparing aluminum nitride powder with high purity and chemical stability by self-propagating high temperature synthesis is provided. CONSTITUTION: The preparation method of aluminum nitride powder includes the steps of (i) mixing 30-80wt.% of metal aluminum powder with a particle size of less than 100μm with 20-70wt.% of aluminum nitride until its density reaches 20-50% of theoretical density; (ii) keeping the reaction system under a nitrogen atmosphere ranging from 1 to 50 atm; (iii) by applying high voltage to a hot wire, elevate the temperature of a mixture of metal aluminum powder and aluminum nitride powder to a temperature where self-propagating high temperature synthesis start; and (iv) crushing obtained aluminum nitride lump. In the first step, 1-40wt.% of a mixture containing carbon powder, halogen compounds of 1 group, 2 group, and 3 group or their hydrate is further added, based on the total weight of the mixture.