MATERIALS TRANSACTIONS
Online ISSN : 1347-5320
Print ISSN : 1345-9678
ISSN-L : 1345-9678
Improved Mechanical Properties of Al2O3 Ceramics by Sputtered TiN Coatings
Chia-Hui ChienFeng-Min LaiChih-Wen ChengSin-Liang OuShu-Chuan LiaoTsan-Ming SuYao-Tsung Yang
Author information
JOURNAL FREE ACCESS FULL-TEXT HTML

2017 Volume 58 Issue 10 Pages 1392-1396

Details
Abstract

In this study, TiN thin films have been prepared as the coating layers on Al2O3 ceramic substrates to enhance the mechanical properties of Al2O3 ceramics. TiN films with various thicknesses of 0.5 and 1 μm were deposited by DC sputtering at room temperature. The TiN film prepared on the Al2O3 substrate has a columnar structure without large bumps or steps formed on the film's surface. Without the TiN coating, the average friction coefficient of the Al2O3 substrate was 0.51. As 0.5- and 1-μm-thick TiN films were coated on Al2O3 substrates, the average friction coefficients 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 confirmed 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 film 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 film 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.

Fig. 2 Friction coefficients as a function of sliding distance for the Al2O3 substrate, 0.5-μm-thick TiN/Al2O3 substrate, and 1-μm-thick TiN/Al2O3 substrate. Fullsize Image
Content from these authors
© 2017 The Japan Institute of Metals and Materials
Previous article Next article
feedback
Top