Sliding Wear Behavior of High Velocity Oxy-Fuel Sprayed WC-CO Coatings

Abstract

The Thermal spraying techniques are coating processes in which melted materials are sprayed onto a surface and the feedstock is heated by electrical or chemical means. High velocity oxy-fuel (HVOF) spraying is seen as the pre-eminent process for deposition of such coatings. The coating that is formed is not homogenous and typically contains a certain degree of porosity, and, in the case of sprayed metals, the coating will contain oxides of the metal. This paper examines the effect of WC–Co coatings on the wear behaviour, WC were thermally sprayed by a high-velocity oxy-fuel (HVOF) system from WC–12% Co powder. Sliding wear resistance of this coating was calculated using pin-on-disk tribometer (ASTM G99-90). The morphologies of WC-Co coating were observed by X-ray diffraction (XRD), Energy dispersive analysis and Scanning electron microscope (SEM). Micro hardness is calculated by using Vickers Hardness test. And it was found that WC-Co coatings show better wear resistant properties.