High-entropy design and its influence on glass-forming ability in Zr–Cu-based metallic glass

Abstract

The glass-forming ability of Zr–Cu-based metallic glass with high entropy is investigated. Samples are prepared by adding elements, such as Ag, Hf, and Ni, to ternary Zr48Al7Cu45 to systematically evaluate the multicomponent effect. The glass structures are fabricated by tilt casting. In quaternary and senary alloys with increased glass-forming ability, new competitive liquid crystalline phases are generated with the addition of elements. Compared with the quaternary alloy, the quinary alloy does not form a new crystalline phase, and the added Hf is highly soluble in the base crystalline phase. The driving force for crystallization, which is evaluated based on specific heat measurements, is the largest for the quinary alloys. This suggests that stabilization of the competitive phase by the high-entropy effect leads to a decrease in the glass-forming ability. From the kinetics point of view, the relationship between the liquid-phase fragility and glass-forming ability is clarified, and the addition of Ag and Ni, which strengthens the liquid properties, is found to improve the glass-forming ability. Based on the high-entropy strategy, a new high-entropy metallic glass Zr35Hf13Al11Ag8Ni8Cu25, with a maximum vitrification diameter of 20 mm, is fabricated.