Synthesis of submicron AlN powder using dynamic/thermochemical method

Abstract

Carbothermal reduction and nitridation (CRN) method, used for the synthesis of nitride-based ceramic powders, is an effective and economic technique that has been widely investigated. In this study, a CRN-based novel approach, denominated as dynamic/thermochemical method (DTM), has been used to synthesize submicron high-purity aluminum nitride (AlN) powders with equiaxed-sized particles. DTM is a modified CRN method in which the reaction takes place in a controlled atmosphere using a rotary tube furnace, allowing the synthesis of fine particle-size powders in a relatively short time. Following the DTM process, homogeneous submicron AlN powders were synthesized from a mixture of aluminum hydroxide (Al(OH) 3 ) and carbon black at 1450 • C for 1.5 h. Furthermore, dynamic synthesis parameters, as well as the use of ammonia (NH 3 ) and propane (C 3 H 8 ) gas mixtures instead of carbon black and nitrogen, were investigated.