Erosion of PVD TiN coatings under simultaneous corrosion in sodium carbonate/bicarbonate buffer slurries containing alumina particles

Abstract

Following a preceding report, this paper summarises preliminary results for the study of PVD TiN coatings prepared on mild steel, BS6323, under potentiodynamically controlled corrosion during erosion in an alkaline slurry containing alumina particles. The erosion term was obtained when the total erosion–corrosion loss had been measured by sample weighing and the corrosion term obtained as described previously. The erosive wear tracks were examined, in conjunction with investigation into evidence of corrosion damage, by scanning electron microscopy. The significant, superior erosion resistance of the coating to that of the uncoated mild steel and AISI 304 stainless steel mainly resulted from the exceedingly high coating strength and its stability under the simultaneous corrosion attack. The erosion term was compared with the previously measured corrosion term, and their respective contributions to the overall erosion–corrosion damage evaluated for each sample.