Microstructure and Mechanical Properties of CrAlTiCN Multilayer Films by Magnetron Sputtering Ion Plating

CrAlTiCN multilayer films have been prepared by closed-field unbalanced magnetron sputtering technology using graphite target as the C supplier. TEM observation results show that the CrAlTiCN films have a clear multilayer structure with the modulate periods changed with the current of graphite target. The higher the current of graphite target, the thicker the periodical thickness of multilayer film. The microstructure of CrAlTiCN films is that the (Cr,Al,Ti)N/amorphous carbon multilayer where (Cr,Al,Ti)N layer and amorphous carbon layer appeared interval, the volume fraction of the amorphous carbon increased with the increasing current of graphite target. Measurement results showed that the CrAlTiCN multilayer films have high microhardness and low friction coefficient. Based on the relationship of the microstructure and properties of films, the multilayer structure and fine grain size of (Cr,Al,Ti)N phase are responsible for their excellent mechanical properties. The good tribological properties are attributed to the amorphous carbon phase (sp2 C-C).