Optimization for toughness in metalloid-free Ni-based bulk metallic glasses

The toughness of metalloid-free Ni-based bulk metallic glasses (BMGs) manifests a concentration dependency. In terms of measured notch toughness, Ni40Cu2Pd2Zr27.6Ti18.4Al10 BMG exhibits the optimal toughness among the six investigated alloys. Its fracture energy is comparable to Fe-based BMGs with optimal toughness. In contrast to the Poisson’s ratio, the shear modulus is much more sensitive to composition change in the Ni-based BMGs. Improvement in toughness of Ni-based BMGs roughly scales with reducing the shear modulus or glass transition temperature.