Development of Novel Diamond/cBN Materials via Ultra-high Pressure and High Temperature

Abstract

ABSTRACT

Novel ultra-hard materials: single-phase (binderless) polycrystalline diamond and cBN, have been produced by direct conversion sintering under static high pressure and high temperature. The polycrystalline diamond and cBN consist of fine grains of several tens or hundreds nano-meters without containing any secondary phases or binder materials. They have high hardness and high strength which surpass those of their single crystals and conventional sintered compacts containing binder materials. The fine microstructure features without any secondary phases and surpassing mechanical properties of the single-phase polycrystalline diamond and cBN are promising for applications in next-generation high-precision and high-efficiency cutting tools.