Preparation Of Si₃N₄/SiC From Kerf Loss By SHS Method

In recent years, the capacity of china photovoltaic industry has been very large, so it’s in very need to find an environmentally friendly and economic way to deal with the silicon kerf loss from photovoltaic industry. The liquid composition inside the silicon kerf loss, such as polyethylene glycol, has been dealing well with; but the silicon debris and silicon carbide inside the silicon kerf loss is still been researched to deal with by many other researchers.In this paper, silicon kerf loss was reused to try to produce complex phase Si3N4/SiC ceramic by SHS, the following work is been done.1. Si3N4/SiC ceramics powders were prepared feasibly by combustion synthesis using kerf loss powders and commercial silicon powders as starting materials. The reaction influence of different silicon powder content, nitrogen pressure is studied, and such influence will obviously change the reaction.2. Because the silicon nitride whisker generation is an important factor to determine material performance. To further study the azotized silicon whisker growth mechanism, The process that the oxide as a promoter, different fineness of silicon powder as the starting material to grow whisker is studied. too fine silicon powder is not suitable for Si3N4 whisker producing.3. The whisker growth model is established in this paper. The complex combustion process under the condition of silicon powder are summarized, analyzed and calculated. Combining with the experimental phenomena, analyzing the reaction of silicon powder under high pressure nitrogen and whisker growth process, a set up of whisker growth model is found to explain the result of the experiment.