| Abstract: |
Thermally sprayed chromium carbide-based coatings are being widely used for a variety of wear resistance applications in hydraulic cylinders, piston rods, valve stems, turbine components, sieves and cones, ship engine valve spindles, pump housings to improve the resistance to sliding, abrasive and erosive wear. These coatings deposited by high velocity process like high velocity oxy-fuel (HVOF) technique is known to provide improved wear performance. Chromium carbide-based materials are generally employed to produce hard coating for elevated temperature wear application including sliding, fretting, abrasion, and erosion. In the present study, Cr3C2-20(NiCr) coatings are deposited by HVOF process, and abrasion wear resistance of coatings are tested under various test conditions. The abrasion tests (ASTM G65) were done using a three-body solid particle rubber wheel test rig using silica and alumina grits as the abrasive medium in different loads. The results indicate that the abrasion performance of the HVOF sprayed Cr3C2-NiCr coating is controlled by the cohesion between splats and can be further enhanced by improving splat cohesion. The removal of carbide particles in the coating was mainly responsible for the abrasive wear of the coating. The content and particle size of the Cr3C2 carbides were the two key factors controlling the abrasive wear of the coatings. It was found that the abrasion resistance of HVOF coating is significantly higher than mild steel.
Keywords: HVOF, Cr3C220(NiCr), Wear, ASTM G65
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