科研之友
微信
新浪微博
Facebook
分享链接
摘要
Transition metal oxynitrides have become emerging decorative coating materials due to their adjustable coloration and high hardness and corrosion resistance. This research studied the effect of oxygen content on the coloration, mechanical properties and corrosion resistance of ZrNxOy thin films deposited on AISI 304 stainless steel using hollow cathode discharge ion plating (HCD-IP). The Zr/N/O ratios of the ZrNxOy films were determined using X-ray photoelectron spectroscopy (XPS). The color of the ZrNxOy thin film changed from golden yellow to blue and then slate blue with increasing oxygen content. X-ray diffraction (XRD) patterns revealed that phase separation of ZrN and m-ZrO2 occurred as the oxygen content reached 31.2 at.%. ZrN(C) (ZrN with dissolving oxygen) is dominant at oxygen content less than 18.1 at.%, while m-ZrO2 phase was prevailed at oxygen content above 40.3 at.%. Phase separation lowered the hardness of the ZrNxCy films as the fraction of ZrC2 was less than 40%. The residual stresses in ZrN phase was higher than that in Zr02, and the residual stress decreased for the specimen containing 30 to 37% ZrO2. For the samples containing more than 44% ZrO2, the average residual stress was close to that in Zr02 phase. The corrosion resistance was evaluated by salt spray test and potentiodynamic scan in two solutions: 0.5MH(2)SO(4)+0.05 M KSCN and 5% NaCl solutions. The results showed consistent trend in the two solutions. From the results of potentiodynamic scan, corrosion resistance increased as the packing density of the film increased, whereas the film thickness was not a crucial factor on corrosion current; moreover, the electrical conductivity of the film may be one of the significant factors in corrosion resistance. Results of salt spray tests suggested that the corrosion of ZrNxOy in NaCl may play an important role in corrosion resistance.
- 出版日期2008-7-15
- 单位清华大学
