An effort to enhance adhesion of diamond coatings to cemented carbide substrates by introducing Si onto the interface

For diamond-coated cemented carbide cutting tools, adhesion of the coatings remains to be a problem. This problem originates from the fact that the adhesion mechanism of the coating–substrate system is mechanical in nature and hence the adhesion of the coatings is ordinarily weak. As an effort to improve adhesion of diamond coatings to the substrates, Si was introduced into the diamond chemical vapor deposition (CVD) process, in order to produce a chemically active glue interface between the diamond coatings and the substrates. Preliminary results showed that by introducing a nontoxic precursor, octamethylcyclotetrasiloxane (D4), and under normal microwave plasma CVD conditions, Si could be made concentrating onto the interface, benefiting the improvement in adhesion of the diamond coatings.