Sliding Abrasion Wear Assessment of Al 2 o 3 -SiC Nanocomposite Coatings

Abstract

The present work describes abrasion wear tests that were carried out on low carbon steel test wheels coated with a series of high velocity oxygen fuel (HVOF) and plasma sprayed Al₂O₃ - SiC nanocomposite coatings with varying SiC contents. These were compared with pure Al₂O₃ coatings applied by HVOF and with uncoated steel. The HVOF sprayed coatings exhibited consistently superior abrasion wear resistance compared with plasma sprayed coatings of equivalent composition and were much better than uncoated steel. Overall, the HVOF Al₂O₃ - 10SiC nanocompo2 site coating showed the best abrasion resistance of all the coatings tested. They were worn very slowly by a microabrasion process. The poor performance of the plasma sprayed coatings was attributed to inefficient in flight melting of the particle agglomerates during the deposition process. This resulted in coatings with a low cohesive strength, which made them particularly vulnerable to particle pull out during abrasion testing.