Study of diamond adhesion behavior on chromium and titanium for obtaining adherent diamond coatings on steel

It is known that diamond films display poor adhesion on metals such as copp er and steel. One solution to overcome the poor adhesion is to use interlay er materials, In this study we report results of an investigation of the ad hesion behavior of diamond on pure chromium (Cr) and titanium (Ti) substrat es, Cr and Ti are promising interlayer materials for adhering diamond to st ainless steel. The coating adhesion was studied using indentation tests com bined with acoustic emission signals during loading. It was found that a 10 5-N load indentation caused the film to delaminate from the Cr substrate, w hile the diamond film remained attached to the titanium even after the inde ntation at 180 N. Micro-Raman spectroscopy was used to monitor the film str ess. The diamond films grown on Ti substrates were found to be less stresse d than the films grown on Cr substrates. Therefore, Ti was used in thin-fil m form to obtain adherent diamond coatings on steel.