Nanostructure reactive plasma sprayed TiCN coating

TiCN coating was prepared by reactive plasma spraying technology using titanium and graphite powder. The composition, microstructure, mechanical properties and wear resistance were investigated by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscope, digital vickers microhardness tester and block-on-ring sliding apparatus. The results show that TiC0.7N0.3 coating with a thickness > 300 μm was prepared and it consists of a mixture of nanostructure and amorphous TiC0.7N0.3, Ti3O, CNx and C phases. The phases mainly formed columnar grains and dentrite-like grains. The TiC0.7N0.3 coating possesses excellent strength-toughness and wear resistance. The microhardness is 1674 ± 197 HV0.1 and the fracture toughness is 3.76 ± 0.31 MPa·m1/2. The high hardness is mainly attribute to grain refinement and solid solution hardening. The excellent wear resistance is attribute to the high strength-toughness and the graphite lubricating film.