High Temperature Oxidation Resistance of Magnetron Sputtering and Multi-arc Ion Plating Cr Films on Zirconium Alloy

In order to study the high temperature oxidation resistance of Cr films deposited using magnetron sputtering (MS) and multi-arc ion plating (MAIP) methods, Cr films with a thickness of approximately 5 mu m were deposited on the surface of zirconium alloy through different methods. The oxidation kinetics curve was used to compare the high temperature oxidation resistance of the coating at 800 degrees C. Microstructure and phase structure of the films were investigated by SEM, XRD and EDS, respectively. The results show that the high temperature oxidation resistance of zirconium alloys is significantly enhanced by the Cr fims depoisted by MS and MAIP. The Cr films surface deposited by MS is continuous and uniform without obvious cracks, however, many holes(0.40%) are observed after high temperature oxidation of 7 h. The oxidation resistance is increased by 6.434 mg/cm(2). Compared with the Cr films deposited by MS, the single optimal orientation (211) of the Cr films deposited by MAIP is vanished. Cr films have uniform thickness, smooth surface and clear layer/matrix interface. Moreover, only 0.21% holes exist on the films' surface which shows the stronger high temperature oxidation resistance. The oxidation increase of Cr films is 5.616 mg/cm(2), remaining compact after high temperature oxidation of 7 h.