Abstract
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 as-cast button ingots after arc melting in high-purity Ar, and the cross-sectional solidification morphology of arc-melted 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 as-cast 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.