Abstract
Diamond coated cutting tool was prepared by microwave plasma CVD in the CO-H2 reactant system using silicon nitride substrate. A graded interfacial textrue between diamond film and silicon nitride substrate was formed by acid and microflawing pretreatments of the substrate and by the sub-sequent two-stage CVD treatment The correlation among the graded microstructure, film thickness distribution and cutting performance of the coated specimens was investigated. Long life of the silicon nitride cutting tool with thick diamond coating was verified by the milling test using Al-20wt%Si alloy as work material.
