INVESTIGATION ON THE INFLUENCE OF SUBSTRATE MATERIALS ON THE TRIBOLOGICAL BEHAVIOUR OF DETONATION GUN SPRAYED ALUMINA COATING

Detonation Gun (D-Gun) Spray Coating is a widely used surface strengthening process applicable for many machine elements and engineering components. D-Gun process gives the unique capability to produce hard surface layers with residual compressive stress, superior adhesive strength and the least porosity in comparison with other thermal spray processes. In addition, flexibility to manufacture the components initially using relatively softer and cheaper materials followed by modification of the functional surfaces using detonation gun spraying of harder materials is a welcome alternative. Experiments were conducted to study the influence of select substrate materials on the behavior of the detonation gun sprayed alumina coatings using optimized process parameters. The experimental investigations relied on the measurement of microhardness, surface roughness, friction and wear behavior as well as by Scanning Electron Microscope (SEM) image analysis of the sprayed alumina coatings on different substrate materials – Stainless Steel SS304, SS316 and Aluminum alloy AA1050. Experimental results suggest that the tribological response of the alumina coated on aluminum alloy in comparison with stainless steels produced durable surface coatings that are superior in resisting environmental degradation.