Effect of microalloying on the toughness of metallic glasses

The effect of microalloying on the toughness of Cu-Ti-based metallic glasses is explored. Minor additions of Si and Sn in glass former Cu_(47)Ti_(34)Zr_(11)Ni_8 known to improve glass-forming ability are found here to sharply decrease toughness. The drop in toughness is associated with a small but meaningful increase in shear modulus, glass-transition temperature, yield strength, and a decrease in Poisson's ratio, implying a negative correlation between toughness and shear flow barrier. The strong influence of minor additions on the glass properties could be a useful tool for simultaneously tuning both the glass-forming ability and toughness of metallic glasses.