Crystallization and nanoindentation behavior of a bulk Zr-Al-Ti-Cu-Ni amorphous alloy

The crystallization and nanoindentation behavior of a Zr-10Al-STi-17.9Cu-14 .6Ni (at.%) bulk amorphous alloy (BAA) were studied. Resulting from the kin etic nature of phase transformation in multicomponent alloys, the crystalli zation path is complex. Despite the complexity of different crystallization paths, the main final crystallized product in the Zr-based BAA is Zr2Cu. Y oung's modulus and hardness of the BAA were found to increase with an incre ase in annealing temperature. The observed mechanical properties were corre lated with the microstructure of the material. Also, in the present paper, both the observed crystallization and nanoindentation behavior are compared with existing data. Zr-based BAAs exhibit a ratio of hardness to Young's m odulus (H/E ratio) of about 1/10, suggesting the interatomic bonding in the alloys is close to being covalent.