Microstructure and Mechanical Properties of Multilayer Ti(C, N) Films by Closed-field Unbalanced Magnetron Sputtering Ion Plating

Ti(C, N) multilayer films have been prepared by closed-field unbalanced magnetron sputtering technology and using graphite target as the C supplier. Microstructural observation results showed that the Ti(C, N) films exhibited multilayer structure with most of fine nano-columnar Ti(C, N) grains existing in the films. The current of graphite target had an effect remarkably on the multilayer structure of films: the periodical thickness gradually increased as the current went up, but the grain size of films gradually decreased and even amorphous phase appeared as the current further increased. The microstructure of Ti(C, N) films changed from columnar crystallite to nanocomposite in high current of graphite target where the fine Ti(C, N) grains were distributed uniformly in the amorphous Ti(C, N) matrix, and the volume fraction of the amorphous phase increased with increasing current. Measurement results showed that the Ti(C, N) multilayer films have high microhardness and low friction coefficient, and especially the film deposited in the current of 0.9 A exhibits superior properties with optimizing hardness and friction coefficient. Based on the relationship of the microstructure and the properties of films, the multilayer structure and fine grain size of Ti(C, N) films are responsible for their well mechanical and friction properties. And choosing the graphite target as the C supplier is more propitious to decrease the friction coefficients of films.