COMPACTING METHOD FOR STARTING MATERIAL FOR SYNTHESIZING CUBIC SYSTEM BORON NITRIDE

摘要

PURPOSE:To encance the utilization efficiency of a superhigh pressure space in the manufacture of cubic system boron nitride (CBN) by a high pressure synthesizing mehtod to economically form a high density CBN product by precompacting starting material prior to final compacting. CONSTITUTION:In a mehthod of compacting starting material for synthesizing CBN prepared by adding a catalyst for synthesizing CBN such as an Si-Al mixture to graphite type boron nitride (HBN) with a high pressure apparatus composed of a metallic mold having a cavity and of a punch to be inserted in the cavity, said starting material is precompacted once or more under >=about 0.5kb surface pressure to efficiently obtain a CBN product. The preferred cavity size of a metallic mold for precompacting is >=about 1% smaller than the cavity size of a metallic mold for final compacting.