Hydrogen-induced amorphization of Zr-Cu-Ni-Al alloy

Arc melting was utilized in this study to produce Zr₅₅Cu₃₀Ni₅Al₁₀ alloys under mixed atmospheres with various ratios of high-purity hydrogen to argon. The influences of hydrogen addition on the solidification structure and glass-forming ability of Zr₅₅Cu₃₀Ni₅Al₁₀ alloy were determined by examining microstructures in different parts of the cast ingots. The results showed that different degrees of crystallization structures were obtained in the ascast button ingots after arc melting in high-purity Ar, and the cross-sectional solidification morphology of arcmelted ingots was found to consist of crystals with varying from the bottom up. By contrast, there were completely amorphous structures in the middle and upper areas of the as-cast button ingots fabricated by adding 10% H₂ to the high-purity Ar atmosphere. A clear solidification interface was found between the crystal and glass in the ascast button ingots, which indicates that hydrogen addition can enhance the Zr₅₅Cu₃₀Ni₅Al₁₀ alloy’s glass-forming ability. The precise mechanism responsible for this was also investigated.