Effect of Film Thickness on the Structure and Properties of Nanocrystalline ZrN Thin Film Deposited by Ion Plating

• Main Authors: Yang Hao-Chung, 楊濠仲
• Other Authors: 黃嘉宏
• Format: Others
• Language: en_US
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/94264453007031399483

碩士 === 國立清華大學 === 工程與系統科學系 === 91 === Nanocrystalline ZrN thin films were successfully deposited on Si (100) and AISI 316 stainless steel substrates using hollow cathode discharge ion plating (HCD-IP) system. The objective of this study was to investigate the effect of film thickness on the composition, structures, mechanical properties, and corrosion resistance of the ZrN film. The results showed that (111) was the dominant preferred orientation in ZrN films. The effects of the film thickness were significant on the N/Zr ratio, roughness, and grain size. The packing factor was only slightly varied with film thickness and the thinnest specimen reached a quite high packing factor of 0.8. Nanoindentation data indicated that hardness of the films was not related to the film texture and the residual stress. The minimum grain size required for the activation of dislocation slip in nano-sized grains was estimated to be ~85nm. The deformation mechanism of the ZrN film may be due to grain rotation and grain boundary sliding followed by mass transfer, instead of dislocation mechanism. The residual stress of all ZrN films was compressive, and did not vary with film thickness. The high compressive residual stress was associated with the incorporation of metal atoms on nitrogen sites, and the nitrogen interstitials. The results of potentiodynamic polarization scan in both 5% NaCl and 0.5M H2SO4 + 0.05M KSCN solutions were consistent with that by salt spray test. A nanocrystalline ZrN film thicker than 400 nm could effectively protect the substrate from the corrosive medium, if the packing factor is sufficiently high.