Effect of Ag addition on the oxidation behavior of CrAlN coating at elevated temperatures

Abstract

The effect of oxidation temperature and amount of Ag addition on CrAlN coating was investigated in this study. No Ag and Ag-based CrAlN coatings were deposited on a substrate using a physical vapor deposition (PVD) technique. The coatings then were isothermally heated at 800 °C and 900 °C for the 2 hr. Interestingly it is found that even with a small difference in temperature (100 °C), CrAlNAg coating shows different nature of oxidation, mass gain curve, coating microstructure and surface morphology.Surface morphology revels the Ag clusters formation on the top associated with the high temperature heating. While cross-section morphology gives information about Ag distribution and oxides layer formation. Mass gain curve and EDS (Energy-dispersive X-ray spectroscopy) results revealed that the oxidation resistant behavior of the CrAlN coating was degrade with increasing Ag content and/or increasing oxidation temperature. Overall, the results suggest that the temperature has a significant effect on the microstructure and properties of Ag-based coatings, and optimizing the deposition temperature can improve the performance of these coatings in various applications.