TiCN coating, owing to its superior wear-resistance, has been frequently applied in many fields. TiCN thick coating was first prepared by reactive plasma spraying. The phase composition, microstructure and tribological properties of the TiCN coating were investigated in this research. Experimental results show that the microstructure of the TiCN coating was quite dense, and there was also a little amount of titanium oxides within the coating. By XPS analysis, Ti-C and Ti-N bonds were detected in the coating. The TiCN coating exhibited superior wear-resistance. The failure mechanism was attributed to the ad-hesive wear, the grinding of TiCN hard-grain, as well as the coating failure by oxidation. There were more Fe, Cr, O, etc. in the failure zone, suggesting that the corrosion propagated gradually from sur-face to interior.
ZHU Lin HE JiNing YAN DianRan XIAO LiSong DONG YanChun XUE DingChuan MENG DeLiang
The nanostructured TiN coatings were fabricated by the reactive plasma spraying, and the micro-structure of the coatings was analyzed by XRD, SEM and TEM. The results show that the coatings are composed of TiN and Ti3O phases, and the coatings have the typical sprayed lamellae structures. The nanoscale grains with particle diameters less than 100 nm are observed in the coatings by TEM, and both fine equiaxed and columnar grains are found simultaneously in the nanostructured TiN coatings. Furthermore, the deformation twins are verified by TEM in the coatings, which are caused by the high cooling rate and the non-uniform temperature distribution in the plasma jet.
ZOU DongLi YAN DianRan HE JiNing XIAO LiSong DONG YanChun
TiN coating was prepared by reactive plasma spraying in the Ar and N2 containing plasma jet. The resuits of XRD show that the TiN coating consists of TiN and Ti3 O, neither Ti2 N nor TiO2 phases. The toughening mechanism was characterized by analyzing the SEM morphologies of the TiN coating＇s indentation of microhardness and fracture surfaces. The results indicate that the coating possesses a high toughness. The adhesion strength among the TiN layers is 25.88 MPa, which is slightly lower than that of the Ni/AI bonding coating. The oxidation process of the RPS TiN coating is TiN→Ti3 O→TiO2.
ZOU Dong-liYAN Dian-ranHE Ji-ningLI Xiang-zhiDONG Yan-chunZHANG Jian-xin
