MINOR ELEMENTAL ADDITIONS IN HIGH OXYGEN CONTENT ZR-CU-BASED ALLOYS

Abstract

Zr-based BMGs are extremely sensitive to the presence of oxygen which is typically considered as an impurity that deteriorates glass forming ability (GFA). It is thus of great interest to consider oxygen as an alloying element and be able to pinpoint a new alloy composition with similar GFA. The GFA of high O-content binary and ternary Zr-Cu alloy systems using sponge Zr have been studied. A shift in the best glass former composition was found for both alloy systems in comparison with their low oxygen content counterparts using the expensive high purity crystal bar Zr. Maximum critical size for the binary Cu-Zr was retained at 2 mm while a 5 mm composite was obtained for the ternary Zr-Cu-Al alloy. Competing phases for glass formation remained the same. The effect of minor elemental addition of Ni and Y were also studied on the ternary high O-content Zr-Cu alloy system.