PROCESS FOR THE PREPARATION OF SINTERED BODY OF SILICON NITRIDE

摘要

After molded body is made by adding a sintering adjuvant 4-10wt.% into Si3N4 powder, it is sintered primarily at 1600-1800 deg.C under 2-5 atm. nitrogen gas for 10-30 min to have a sintering density of 95% and sintered secondarily under 50-100 atm. nitrogen gas pressure for 0.5-4 hours to have at least 95% density to give a high abrasion resistant Si3N4 sintered body. The used sintering adjuvant consists of AlN 2-7wt.%, Y2O3 2-5wt.% and MgO's ratio is less than 1wt.%.