Oxidation Behavior of Cr_(1-x)Al_xN Coatings Deposited by Closed Field Unbalanced Magnetron Sputtering at 800°C

摘要

CrN coating possesses high strength, hardness and good resistance to friction. In order to further improve the performance of CrN coating, especially the high temperature resistance, a series of Cr_(1-x)Al_xN coatings with different Al content were deposited on the surface of 316 stainless steel by closed field unbalanced magnetron sputtering (CFUBMS). The microstructure, mechanical properties of Cr_(1-x)Al_xN coatings were investigated by XRD, FESEM/EDS and microhardness tester, respectively. The oxidation behaviors of Cr_(1-x)Al_xN coatings at 800°C were also studied. The results showed that with the increase of Al content, the hardness of the coating decreased first and then increased, and the binding force decreased gradually and then increased rapidly, it gains the lowest value when Al content reach to 32%, and its microstructure is gradually refined. The phases in CrAlN coatings are mainly CrN and A1N. As the amount of Al increases, the number of dense oxide films on the surface of the coating increases, increasing the antioxidant capacity of the coating.