LAUSR

In this study, TiN thin lms have been prepared as the coating layers on Al2O3 ceramic substrates to enhance the mechanical properties of Al2O3 ceramics. TiN lms with various thicknesses of 0.5 and 1 μm were deposited by DC sputtering at room temperature. The TiN lm prepared on the Al2O3 substrate has a columnar structure without large bumps or steps formed on the lm’s surface. Without the TiN coating, the average friction coef cient of the Al2O3 substrate was 0.51. As 0.5and 1-μm-thick TiN lms were coated on Al2O3 substrates, the average friction coef cients of these two samples reduced to 0.36 and 0.32, respectively, revealing the tribological characteristics of Al2O3 ceramic was enhanced with the TiN coating. Additionally, the 1-μm-thick TiN/Al2O3 sample possesses a slightly higher attrition resistance than that of the 0.5-μm-thick TiN/Al2O3 sample, and this can be also con rmed by performing the elemental mapping method on the wear-treated samples. From the adhesion performances, we observed no critical load of LC2 appeared in these two samples during the scratch test, while the critical load of LC1 values were 11 and 9 N for 0.5-μm-thick TiN/Al2O3 and 1-μm-thick TiN/Al2O3, respectively. Due to the increment of TiN thickness, the internal stress formed in the lm would increase. This is the reason why the 1-μm-thick TiN/Al2O3 sample has a lower critical load of LC1. Obviously, the 0.5-μm-thick TiN lm coated on the Al2O3 substrate has a better adhesion characteristic. According to these results, the sputtered TiN coating is indeed useful for improving the mechanical properties of Al2O3 ceramics, in particular for the 0.5-μm-thick TiN coating. [doi:10.2320/matertrans.M2017097]