PROCESSW FOR PRODUCING SILICON NITRIDE OF HIGH ALPHA PHASE CONTENT

摘要

PCT No. PCT/SU89/00086 Sec. 371 Date Jan. 12, 1990 Sec. 102(e) Date Jan. 12, 1990 PCT Filed Apr. 3, 1989 PCT Pub. No. WO89/11447 PCT Pub. Date Nov. 30, 1989.The invention relates to preparing refractory inorganic compounds, particularly, to methods of preparing silicon nitride with a high a -phase content. The method of preparing silicon nitride with a high alpha -phase content is accomplished by means of self-propagating high-temperature synthesis. The method includes contacting the charge containing a silicon-reagent with an additive in a nitrating medium. The silicon-reagent is metallic silicon and at least one ammonium halide is used as an additive in the amount of 1-60% of the mass of metallic silicon. The synthesis is carried out at a pressure of 4-30 MPa.