Impact of CrAlN Coatings on Oxidation Behavior of K38G alloy at 800 and 900°C

CrAlN coatings have been deposited on K38G alloy by Closed Filed Unbalanced Magnetron Sputter Ion Plating(CFUMS1P). The microstructure, surface and section morphology of CrAlN coatings before and after oxidation were analyzed by XRD and SEM. At the same time, the mechanical properties and oxidation resistance of CrAlN coating were also studied. The results indicate that the phases in the isometric crystal CrAlN coatings with a hardness of 3500 I-1V and a adhension of 20 N was the coexistence of CrN and AIN. Each element of CrAlN coatings still existed at 800 and 900 degrees C, but it demonstrated better high-temperature oxidation resistance because of denser oxide scale at 800 degrees C. Besides, internal oxidation occurred under the two temperatures.