Structure and mechanical properties of TiAlCrSiN coatings deposited on Ti(C,N)-NbC-Ni cermets with varied Mo2C contents

TiAlCrSiN coatings were deposited on Ti(C,N)-NbC-Ni cermets with varied Mo2C contents by medium frequency reactive magnetron sputtering, and their structure, phases, mechanical and frictional properties were investigated in the present work. The results indicated that both the Mo diffusion to the coating and the Al diffusion to the substrate resulted in the decreased lattice parameter of TiAlCrSiN phase in the coating. When increasing Mo2C contents in the substrate, the columnar crystal grains in the coating were refined, whereas the adhesion of the coating to the substrate was degraded as a result of the coating thickening and the inner stress in the coating. Apart from being influenced by grain size, the coating's hardness was also linked to the crystal plane orientation, and it declined with a decrease of relative intensity ratio of I(111)/I(200) in the TiAlCrSiN coating. The elasticity modulus of the coating decreased slightly due to the grain refinement in the coating. The average friction coefficient of TiAlCrSiN coating was reduced by oxidation of the Mo diffused from the substrate, while the friction coefficient was not the predominant indicator influencing wear rate of the coated Ti(C,N)-NbC-Ni cermet.