Correlation between mechanical and thermodynamic properties for La-Ce-Ni-Cu-Al high-entropy metallic glasses

The mechanical properties, thermodynamic features and their correlation were studied for La-Ce-Ni-Cu-Al high-entropy bulk metallic glasses (HE-BMGs). Compressive testing indicated that the HE-BMGs are ductile on a microscopic scale but brittle on a macroscopic scale, because of the low fragility index m of the HE-BMGs. In the non-isothermal process, the activation energies for glass transition for these HE-BMGs are the lowest of the known HE-BMGs. Large values of the Avrami exponent n imply that the crystallization process proceeded through three-dimensional growth and with an increasing nucleation rate. The activation energy for glass transition (E (g)) is almost proportional to the HE-BMG fracture strength, because a higher E (g) is required to dislodge the molecules from the glassy configuration for the HE-BMGs with a high strength. The findings provide unambiguous evidence for the correlation between the mechanical and thermodynamic properties.