Research on Microstructure, Mechanical and Tribological Properties of Cr-Ti-B-N Films

In this study, the Cr-Ti-B-N composite thin films with different Ti and B contents in the films were fabricated by a reactive magnetron sputtering system using chromium (Cr) and TiB2 targets. The microstructure, mechanical properties, and friction properties over broad ranges of temperature were detected by XRD, SEM, TEM, nano-indentation, 3D profilometer, and tribometer. It was found that the Cr-Ti-B-N films exhibited a double face-centered cubic (fcc)-CrN and amorphous-BN structure. As the Ti and B elements were introduced, the hardness and elastic modulus of Cr-Ti-B-N films increased from 21 and 246.5 GPa to a maximum value of approximately 28 and 283.6 GPa for Cr38.7Ti3.7B6.4N51.2 film, and then decreased slightly with a further increase of Ti and B contents. The hardness enhancement was attributed to the residual compressive stress. The friction and wear resistance of the film was improved obviously by the addition of Cr and B, as compared with the CrN film under 200 degrees C.