Abstract: Ti-Al/WC coatings of rare earth oxide-free and containing different composite rare earth oxides were prepared by plasma spraying.The worn surface,cross section microstructure,residual stress and wear mass loss of the coatings were observed and detected by using scanning electron microscopy with energy spectrometer,X-ray powder diffractometer and electronic balance.The wear resistance of the coatings was compared and analyzed by using friction and wear tester.The results show that the internal grains of the Ti-Al/WC coating containing rare earth oxide are refined,particulates are greatly reduced,holes are smaller and the number and size of cracks are significantly reduced.Compared with the coating containing only a kind of rare earth oxide,the composite rare earth oxides are more effective in improving microstructure of the coating.When CeO₂,Y₂O₃ and La₂O₃ are all added into the coatings,the defects in microstructure are the least,the components are most evenly distributed,and the cross section morphologies are the best.At the same time,the residual stress of the coating reaches a minimum of 275.7 MPa,the wear resistance is the strongest and the total wear mass loss is only 16.8 mg,compared with the coating of rare earth oxide-free,they are reduced by 30.3% and 69.8% respectively.

Key words: composite rare earth oxides, Ti-Al/WC coating, microstructure, residual stress, wear resistance