Abradability of Cu-Al₂O₃ gradient coatings by plasma spraying

Cu-Al₂O₃ gradient coatings were prepared by plasma spray.The microstructure and abraded superficial shape of the coatings were analyzed by metallomicroscopy and SEM.The wear-resisting property of Cu-Al₂O₃ gradient ceramic coatings was tested by self-produce immobile wearing machine.The results show that the Cu-Al₂O₃ gradient coatings have not distinct componential saltation and macroscopic interface, and the coatings show the characteristic that structure is not uniform macroscopically but consecutive microscopically.The abradability of the coatings is best when the content of Al₂O₃ is 80% and the abradability is three times than the substrate.The abradability of pure ceramic coatings decreases as the Al₂O₃ content increases.The wear mode changed from cutting and ploughing to the hard phase breaking and pull-out.