Diamond coatings deposited on cemented carbide substrates with SiC as interlayers: Preparation and erosion resistance tests

Abstract

Diamond films could be used as valuable protective coatings in various applications. But on cemented carbide materials, inadequate adhesion remains to be a problem. In this investigation, diamond coatings were prepared on cemented carbide substrates with a high current arc plasma chemical vapor deposition technique. To ensure good adhesion, SiC was deposited on the substrates as interlayers. Scanning electron microscopy, energy dispersive X-ray spectrometry, X-ray diffractometry were used to characterize the interlayers, and Raman spectroscopy, scratching, indentation and micro slurry-jet erosion tests were performed to evaluate quality, adhesion and erosion resistance of the diamond coated samples. Results demonstrate that using SiC as interlayers was effective in ensuring a good adhesion between diamond coatings and the substrates. As a consequence, erosion resistance of diamond coated cemented carbides could be improved by more than an order of magnitude, as compared with that for uncoated cemented carbide samples.