Combustion Synthesis of Si sub 3 N sub 4 and AlN

摘要

Si sub 3 N sub 4 and AlN have been synthesized by combustion of the respective metal powders in high pressure nitrogen gas. The Si sub 3 N sub 4 product consists of a powder containing both the alpha - and beta - forms. While operating in the pressure range of 100 to 1000 atmospheres, the highest yield for Si sub 3 N sub 4 was 95%. An important parameter in producing a high yield is the silicon particle size. A silicon powder with an average particle size of 3 mu m was used in most of the experiments. The optimum experimental conditions are described for the synthesis of Si sub 3 N sub 4 . The AlN formed by the combustion of aluminum powders was in the forms of a dense (approx.92%) part. The experimental parameters control whether the combustion reaction goes to completion and the structure of the product. The preliminary results are favorable for the development of a process to produce dense AlN components using the combustion of aluminum powder in nitrogen gas. 14 refs. (ERA citation 11:016907)