Enhanced Adhesive Strength of Diamond coated on Polycrystalline Diamond Substrate by Optimized Substrate Component

Diamond coating was deposited on polycrystalline diamond (PCD) substrate with CH
4
/H
2
/CO
2
using microwave plasma CVD system. PCD substrates A, B and C which differ in the ratio of metallic binders were predetermined preparation methodology. In order to get better adhesive strength, diamond coating grown on the different PCD substrates was studied. The overall performance of the diamond coating was measured by scanning electron microscope (SEM), Raman spectrum and the Rockwell indentation tests. Results clearly indicate that substrate C is the best substrate among three PCD substrates. In addition, with the decrease of Co and W content in the matrix, the increase of Cu content is helpful to improve the adhesion of diamond bit coating, which provides guidance for the industrialization of diamond bit coating.