Slurry erosive wear behaviour of thermally sprayed Inconel-718 coatings by APS process

Abstract

Inconel-718 powder was thermal sprayed on mild steel substrate utilizing APS (air plasma spray) thermal spraying facility. Coatings of thickness 200 μm and 250 μm were produced by APS using powders of average particle size 50 μm. Developed coatings were subjected to microstructure studies, microhardness test and slurry erosive wear studies in 3.5% NaCl media. Microstructural studies reveal uniformity of Inconel-718 coating with good bond and minimal porosities. The surface hardness of developed coatings were higher than that of the substrate and increases with increase in coating thickness. The slurry erosive wear resistance of developed coatings are superior than that of uncoated mild steel substrate. SEM studies on the slurry eroded surfaces of both uncoated mild steel and Inconel-718 coating have been carried out.