The Ni base alloy (EWAC 1004EN) was used to develop coatings on the mild steel substrate by flame spraying process. The Ni base alloy powder was modified by adding tungsten carbide (10 and 20 wt-%) and CeO 2 to study their effects on the microstructure, microhardness and abrasive wear behaviour of unmodified and modified coatings. All the coatings were subjected to remelting using tungsten inert gas arc welding. The abrasive wear behaviour of all the coatings in different conditions was studied using different normal loads (5, 10, 15 and 20 N) against 120 and 600 grit size abrasive medium. Scanning electron microscopy analysis of the worn out surfaces was carried out to understand the wear mechanisms. It was observed that the remelting of the coatings increased the hardness of WC and CeO 2 modified flame sprayed coatings by ,35%, while the abrasive wear resistance increased by 1?5-to threefold.11 Images (SEM) of 1004ENz20 wt-%WC powder coatings against 120 grit size a as sprayed 20 N load and b remelted 20 N load 12 Images (SEM) of 1004ENz20 wt-%WCz0?8 wt-%CeO 2 powder coatings against 120 grit size a as sprayed 20 N load and b remelted 20 N load Dhakar et al. Remelting of tungsten carbide and RE nickel base alloy coating Surface Engineering

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AISI 1020 steel substrate is coated with alumina as feedstock material using plasma spraying process in order to correlate the microstructural features with mechanical properties of coating. The present work focuses on the effects of microstructural inhomogeneity on mechanical properties of alumina coating through nanoindentation technique. Young's modulus and hardness of the alumina coating are analytically evaluated. Indentation stress-strain curves are generated from the experimentally obtained load-displacement curves to characterise the mechanical properties of the coating. The results have shown large variation in hardness and Young's modulus of alumina due to microstructural inhomogeneity of the coating.

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