Thermal stability and corrosion behavior of Cu-Zr-Al-Y bulk metallic glass

In this study, (Cu0.46Zr0.46Al0.08)(100-X)Y-X (0 <= X <= 8,in at.%) alloy ribbons and rods are prepared by single roller melt-spinning method and suction casting method. X-ray spectra show that the obtained alloy ribbons with X = 0, 2, 4, 8 and alloy rods with X = 0 and 4 at.% Y are fully amorphous. Amorphous rod of 4 at.% Y containing alloy up to 6 mm diameter can be achieved and has a large supercooled region (Delta T-X) up to 75 K. In contrast, alloy rods with either X = 2 or 8 at.% Y contain small amount of crystallites. In H2SO4 solution, the Cu-Zr-Al-Y metallic glass rods form uniform oxide films on surface and have corrosion rate of 0.051-0.073 mm/yr. Pitting occurs when the glass rods are immersed in 3% NaCl solution and sea water and the corrosion rate ranges from 0.194 to 0.286 mm/yr. In all solutions, the corrosion resistance of Cu-Zr-Al-Y bulk metallic glass outperforms 304 L stainless steel. (C) 2010 Elsevier Ltd. All rights reserved.