Isothermal Oxidation Behavior of CrSiN Coating Deposited by Magnetron Sputtering at 700°C

Abstract

CrSiN coatings have been successfully deposited on the surface of GH169 alloy by closed filed unbalanced magnetron sputtering (CFUBMS). The microstructure, chemical and phase composition of the coatings were characterized by SEM, EDS and XRD, respectively. The mechanical properties of the coatings such as microhardness and adhesion strength were measured by indentation method and scratch method, respectively. The isothermal oxidation behavior of CrSiN coating at 700°C was investigated using thermogravimetric analysis. Results show that Cr, Cr2N and CrN coexisted in the dense as-deposited CrSiN coating without Si-containing phases; the coating surface was rough and a small amount of oxide (Cr2O3 and SiO2) was formed on the surface after oxidation at 700°C for 24 hours. The isothermal oxidation result suggested that CrSiN coating possesses excellent oxidation resistance at 700°C. It is considered that the good oxidation resistance of CrSiN coating itself and the formation of dense protectiveCr2O3 and SiO2 films are primarily responsible for the good service performance during the oxidation process at 700°C.