Slurry erosion performance of CeO2-modified Ni–WC coatings

Abstract

Purpose – This paper aims to deal with the study of effect of cerium oxide (CeO2) modification on the sand slurry erosion resistance of Ni – tungsten carbide (WC) coatings. Design/methodology/approach – Flame-sprayed conventional and CeO2-modified Ni–WC coatings were developed on a mild steel substrate. Slurry erosion tests were carried out in an in-house-designed and fabricated pot-type slurry erosion test rig to evaluate wear behavior of conventional and modified coatings. The erosive wear test was conducted using 5 per cent silica sand slurry at 850 rpm. Findings – Modified coatings exhibited increased hardness as compared to the conventional coating. Slurry erosion resistance of most modified coatings was superior to that of the unmodified coating. Hardness of coating doped with 0.9 per cent CeO2 was highest among all coatings, and concomitantly this composition also showed the least wear. Scanning electron microscopy (SEM) revealed that microcutting was much less in the modified coating. Originality/value – Slurry erosion wear of Ni–WC flame-sprayed coatings in sand slurry media is substantiated by extensive SEM study.