Abstract

In order to investigate the formation of AlN, mechanical alloying was carried out in N_2 and NH_3 atmosphere. Differential thermal analysis (DTA), x-ray diffraction (XRD) and chemical analysis were carried out to examine the formation behavior of aluminum nitrides. No diffraction pattern of AlN was observed in XRD analysis of the as-milled powders in NH_3;or;N_2 atmosphere. However, DTA and chemical analysis indicated that the precursors for AlN were formed in the Al powders milled in NH_3 atmosphere. The AlN precursors transformed to AlN after heat treatment at and above 600°C. It was considered that the reaction between Al and NH_3 was possible by the formation of fresh Al surface during mechanical alloying of Al powders.

• Keywords: Aluminum nitride;Mechanical alloying;Direct nitridation;