Surface morphology change in DLC: H coatings with gradient Cr under high temperature and high pressure

Abstract

The pressure influence of the surface morphology of DLC: H Coatings with gradient Cr (DCr) was studied by annealing in argon (HT effect) and HIPping (HT/HP effect). The results show that the voids formed on the HIPping annealed surface are rose-shaped with multi-layered edges but the edge of the voids formed on the argon annealed surface looks single-layered, and the composition of the coating surface is the same after HIPping and argon annealing. The Cr content at the bottom of the voids is higher in the HIPped surface than the argon annealed surface, and the voids formed in the HIPping annealed are relatively smaller but deeper than those in the argon. It is reasonable to deduce that the hydrogen release could have been restricted by the applied high compressive pressure on the surface.