STRUCTURAL FEATURES AND THE CUTTING PROPERTIES OF BORON NITRIDE--BASE SUPERHARD MATERIALS

A group of polycrystalline superhard materials designated Hexanite-R, El'bor-R, Belbor, PTNB, Kiborite, Niborite, Amborite, and Sumiboron were compared. The grain structure and strength of the intergranular and interphase boundaries were determined by electron fractography. Wear resistance was also tested. A Hexanite-R-base cutting layer possessed the greatest life and property stability under test conditions. The results were used to derive specification for a cutting tool.