Tribological behaviour of detonation gun spray coated steel fabricated by laser powder bed fusion technique

This study uses a novel thermal spray based detonation gun method to apply a hard cermet (86WC-10Co-4Cr) coating of 100 μm thickness on tool steel parts fabricated by the SLM process and evaluates its impact on tribological behaviour. The results are compared among as-fabricated, heat treated (500°C, 750°C, 1000°C) samples with air cooling for 6 h and coated samples. The coated sample exhibited 10.65% porosity and an adhesion strength of 141.14 N/mm². The pin on disc sliding wear measurement showed a lower friction coefficient and wear rate of 0.54 and 0.30 mm³/m, respectively, in the coated sample. Post wear surface analysis indicated higher surface roughness in coated sample used in sliding (20.3% Ra, 48.9% Rz) and micro abrasion (60.57% Ra, 24.96% Rz) wear studies than in the as-fabricated sample. The micro abrasion wear test indicated a low friction coefficient of 0.35 and exhibited a smaller crater diameter on the coated surface.