Atomic dynamics in Zr-(Co,Ni)-Al metallic glass-forming liquids

The microscopic transport and the macroscopic flow behavior of Zr-(Co,Ni)-Al melts are systemically investigated using containerless processing techniques. A remarkable decrease of the Co, Ni self-diffusion coefficient and increase of the melt viscosity upon alloying Al, are observed. In contrast to many other metallic glass-forming liquids, the average packing fraction of the melt derived from the measured macroscopic density decreases. Our study indicates that chemical interactions of Al with transition metal atoms play an important role in slowing down liquid dynamics of metal melts, which also contribute to their improved glass-forming ability