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

- Diamond coatings were prepared on cemented carbide by high current arc plasma process.
- SiC was prepared on the substrates and used as interlayers.
- Micro slurry-jet erosion tests were performed to evaluate adhesion and erosion resistance.
- Results show erosion resistance of diamond coated samples was markedly improved.

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.

Diamond coatings were prepared on cemented carbide substrates with SiC deposited on the substrates as interlayers. Micro slurry-jet erosion tests were performed to evaluate adhesion and erosion resistance of the coated samples.It was demonstrated that good adhesion between diamond coatings and the substrates could be obtained through the SiC interlayer strategy. As a consequence, erosion resistance of diamond coated cemented carbide could be improved by more than an order of magnitude, as compared with that for uncoated cemented carbide sample (see the slope of the curves shown in the figures).155