Effect of Sn Addition in the Microstructure Refinement and Corrosion Resistance of Cu-Zr-Al-Ag Alloy

In this paper, a composition of known high glass-forming ability, Cu42Zr42Al8Ag8 and a novel Cu42Zr42Al8Ag4Sn4, were produced by suction-casting. After rapid solidification of both alloys, X-ray diffraction patterns along with crystallite size estimation by Scherrer equation and scanning electron microscopy images revealed a refined microstructure, composed mainly by AlCu2Zr, CuZr2 and Cu10Zr7 phases. Transmission electron microscopy indicated the presence of small crystalline precipitates in the Cu42Zr42Al8Ag4Sn4 suction-casted sample. Polarization curves showed a higher passivation current in the Sn containing sample, suggesting a decrease in corrosion resistance.