Tribological Characterization of Complex Carbides Coating Using HVOF Process

Abstract

quotSurface properties of any engineering components play a major role whenever the working or operating conditions are varied in terms of the nature of load and atmosphere. Though utmost care is being taken while the materials are being selected for the design of the components, to mitigate the demands from the industries to enhance the surface quality for reducing the maintenance cycle time and the material cost. It is required to develop a thin film or coating to resist wear and corrosion as per the requirement. SS304, due to low yield strength and high elongation is much more applicable for complex shapes and sizes. It s used in various products for many sectors like the chemical industry, food industry, automotive and aerospace industries, and pharmaceutical industries. Despite the versatile applications of 304 stainless steel, a major drawback is that it cannot be used in saline environments like near a coastline where chlorine creates pitting problems in the material. Further, it possesses good tensile strength but less hardness will limited uses in tribological applications. As vanadium carbide is a hard phase, it offers good wear resistance and micro-hardness. In the present research, The VC- WCNiCrBSi coating is developed on SS304 Substrate using the HVOF process by varying the VC compositions in the coating powder (VC- WCNiCrBSi) in the range from 5 to 30 %, changing the stand-off distance in the range from 6 to 12 inches, change the preheat temperature in the range from 62.5 to 2500C and post heat temperature from room temperature to 6500C. In HVOF Process the feedstock powder is partially or fully melted in the high pressured and high-energy flame and traveled through the substrate (the metal to be coated). The high pressure of gas increases the kinetic energy of the feedstock powder particle and it produces the mechanical bonding between the melted particle and the substrate surface to develop a thin layer on the substrate surface. From this study, it is concluded that for the complex carbide coating,