Improvement of adhesion properties of TiB2 films on 316L stainless steel by Ti interlayer films

The periodic [Ti/TiB2]n (n=1, 2, 3) multilayered films were prepared on the substrate of AISI 316L stainless steel by magnetron sputtering to enhance the adhesion of TiB2 films based on the remarkable mechanical performance of layered films. The influence of periods on microstructure, adhesion and hardness of [Ti/TiB2]n multilayered films was studied. X-ray diffraction (XRD) analysis shows that the monolayer TiB2 films exhibit (001) preferred orientation, and the preferred orientation of [Ti/TiB2]n multilayered films transfers from (001) to (100) with the increase of periods. The cross-sectional morphology of each film displays homogeneity by field emission scanning electron microscopy (FESEM). The hardness of the films measured via nanoindention changes from 20 to 26 GPa with the increase of periods. These values of hardness are a bit lower than that of the monolayer TiB2 films which is up to 33 GPa. However, the [Ti/TiB2]n multilayered films present a considerably good adhesion, which reaches a maximum of 24 N, in comparison with the monolayer TiB2 films according to the experimental results.