论文部分内容阅读
CrN and Cr-Al-N coatings were deposited on glass substrate and the corrosion behavior of them was studied.The electrochemical tests using both DC (polarization curves) and AC techniques (EIS) were carried out on Potentiostat/Galvanstat (EG&G) in the 3.5 wt% NaCl solution.The surface morphologies of the Cr-Al-N coatings with different aluminum content after corrosion tests were no obvious differentiations of the morphologies between pre-corrosion and after-corrosion except that spallation was observed on the surface of the CrN coating.After being immersed into NaCl solution for 1 hour,the mass of the coating kept constant with the time continuing.It can be explained by the passivation of the coating.The comparison between Ecorr for the Cr-Al-N coatings with different aluminum content revealed that the corrosion potentials for the aluminum contain coatings were nobler than that for CrN coatings.This meant that the addition of aluminum shifted Ecorr to more positive potential values.Among these coatings,CrN in NaCl solution exhibited the worst corrosion resistance,while the corrosion resistance of Cr0.63Al0.37N in NaCl solution was the best.The polarization data and EIS data suggest that addition of aluminum can improve the corrosion resistance of CrN coating.