Solid particle erosion of CVD diamond films deposited at different methane concentration

Abstract

Thick diamond films are synthesized on Si substrate by HFCVD method with different methane concentration (up to 21.9 vol %) in the gas mixture. The erosion resistance of the obtained coatings was investigated by the solid particle erosion of SiC. We show that, regardless of the microstructure, diamond coatings exhibit the same erosion mechanisms. Ring and radial cracks, as well as pin-holes and a local delamination of diamond film were detected for all synthesized films. We found that despite the high degree of initial roughness, the microcrystalline diamond coating showed the maximum erosion resistance at all stages of erosion experiments.