THE CORROSION BEHAVIOR OF SPUTTER-DEPOSITED AMORPHOUS CHROMIUM ZIRCONIUM ALLOYS IN 6 M HCL SOLUTION

Amorphous binary Cr-Zr alloys containing 11-66 at% Zr were successfully prepared by a magnetron sputtering method. Amorphous Cr-Zr alloys thus prepared were spontaneously passive in 6 M HCl solution. Their corrosion rates were four orders of magnitude lower than chromium metal and one-third of zirconium metal and decreased with alloy chromium content. XPS analysis revealed that air-formed films and passive films on the amorphous Cr-Zr alloys were composed of double oxyhydroxides of chromium and zirconium. This appears to be responsible for the high corrosion resistance of the amorphous Cr-Zr alloys in comparison with their constituent elements; the formation of chromium-containing passive film is more protective than the film on zirconium metal, despite the fact that chromium metal dissolves actively in 6 M HCI solution.