The deposition mechanism of coating material during friction surfacing

Abstract

Friction surfacing is a technique that uses frictional energy to improve the functional requirement of the surface. The advantage of this technique is its ability to join dissimilar material in solid state with high bond strength, and also it is energy efficient. The objective of the work is to optimise the process parameters for coating of high quality and to study their deposition mechanism. A vertical milling machine was converted into a friction surfacing tool and was successfully used to deposit metals such as tool steel, stainless steel on medium carbon steel substrate. The deposition was carried out in ambient atmosphere and in an atmosphere of argon and nitrogen mixture. After deposition, the coatings were characterised for microhardness, surface roughness, and bond strength. Scanning electron microscopy was performed to study the bonding mechanism. In order to understand the heat flow in consumable and substrate during the friction surfacing process, a heat transfer analysis was considered essential. As a preliminary step, the temperature at various locations along the consumable, in the substrate and at interface was measured. The heat dissipated through the consumable was calculated using the Fourier law of heat conduction equation. Some important conclusions such as improvement in mechanical properties and quality of the coating produced in argon and nitrogen atmosphere were made.