SURFACE COVERED CUTTING TOOL MADE OF SILICON NITRIDE BASE CERAMIC

摘要

PURPOSE:To enhance the adhesion property of a hard cover layer to the surface of a base in a surface covered cutting tool made of Si3N4 base ceramics. CONSTITUTION:A surface covered cutting tool made of Si3N4 base ceramics and having a hard cover layer which comprises a layer of one kind or plural layers of more than two kinds selected from TiC, TiN, TiCN, TiCNO and Al2O3 and which is formed with an average layer thickness of 1 to 20mum has a denitrified layer of average layer thickness 0.01 to 2mum formed on the surface portion of the base.