Influence of substrate bias on performance of diamond coating on WC cutting inserts for machining of aluminium by HFCVD process

Abstract

The most important factors during deposition on different carbide base cutting tool inserts by using hot filament chemical vapour deposition (HFCVD) method are nucleation and growth of diamond. The negative dc biasing is the most outstanding technique in HFCVD method for improving the nucleation on the substrate surface. In the present investigation, the main objective is to analyse the influence of bias voltage on the WC substrate for nucleation, growth, adhesion and quality of diamond coating along with evaluation of machining performance in dry environment. Finally it has been confirmed that higher nucleation density including good quality diamond coatings along with reduced cutting force and better work surface finish were achieved under a definite reaction pressure with negative substrate bias.