Friction and Wear Study of Molybdenum Coatings on Steel Substrate by HVOF

Abstract

Friction is primary concern in moving machinery parts which causes a gradual loss of materials. Lubrication is one of the best steps to overcome the frictional wear problem. In the light of above problem, researchers are developing best feasible solutions, among which surface coting is a better alternatives. Thermal spray coating is a Surface engineering technique which are used to protect manufactured components from thermal resistance & wear resistance and from corrosive degradation and also to enhance hardness to the existing surface while retaining the ductility and toughness of that component and also improving the decorative and aesthetic appeal. The presence of surface topography and coating play an important role in the Tribological performance of mechanical sliding components. Depending on the coating used, it is possible to reduce friction and wear of components. In this work Molybdenum coating was deposited on the surface of the base steel substrates (SS304 and A36) by High Velocity Oxygen Fuel (HVOF) Coating Method. SEM studies confirmed that least surface damage on surface and the bond between coating and substrate was excellent. The developed coating was subjected to microstructural studies, micro hardness test and pin-on disk test to study the Tribological properties of coated substrate. Developed Molybdenum coatings possess higher hardness, significantly lower friction coefficient and Wear resistant when compared with base steel substrate. SEM studies confirms least surface damage to the developed Molybdenum coatings when compared with steel substrate.