PRODUCTION OF BORON NITRIDE SINTERED COMPACT

摘要

PURPOSE: To obtain a boron nitride sintered compact having new crystal orienting property by using copper as an auxiliary and carrying out heating to the m.p. of copper or above under pressure when a boron nitride sintered compact is produced. CONSTITUTION: A mixture of boron nitride or its precursor with copper or its compd. is pressed at the m.p. of copper or above. The effect of copper as an auxiliary is enhanced by pressing a reactive mixture of boric acid with urea and copper nitrate because a sintered compact contg. copper very finely dispersed in boron nitride is obtd. Pressing is carried out preferably at a temp. between the m.p. of copper and 2300 deg.C. The resultant boron nitride sintered compact has a-axis orienting property. A boron carbonitride sintered compact can be formed by adding a carbonaceous material as well as copper or its compd.