Combustion synthesis of aluminum nitride powder using additives

Aluminum nitride powder was synthesized by a combustion synthesis method us ing various additives. Each additive was mixed with Al powder, and the powd er mixture was then pressed into a compact. The combustion reaction was ign ited by heating the compact under N-2 atmosphere of 0.4 MPa. Additives cont aining halogens were found to have a catalytic effect on the combustion rea ction. High product yields were obtained when using additives of NH4X, CO(N H2)(2), CH3(CH2)(16)COOH, and CO2H(CH2)(2)CO2H. In all these cases, eggshel l-like skins were observed to form on the Al particles at the early stage o f combustion. The catalytic effect, formation of the eggshell-like skins, a nd their effects on the combustion process were investigated and discussed.