Consolidation mechanism, microstructural evolution and corrosion resistance of Inconel 625 coatings

The inter-relationships between geometrical properties, microstructural characteristics and corrosion resistance on one hand and laser-material interaction parameter (α) on the other hand are examined. A laser-material interaction parameter within the range of 599 ≤ α ≤ 400 J.s g−1 mm−1 imparted optimum characteristics of microstructure, microhardness and corrosion resistance. The consolidation mechanism of the coatings indicates that this parameter ensures the formation of a double ‘burn-in’ macrostructure into the substrate which imparts non-porous, crack-free and a fine interfacial microstructure. This study provides guidance in designing Inconel 625 coatings of desirable microstructures and corrosion resistance.