Impact of micro-alloying on the plasticity of Pd-based bulk metallic glasses

Micro-alloying was performed using additions of Co and Fe to monolithic Pd40Ni40P20 bulk metallic glass. Compression tests showed a plastic strain of 13% for the Co addition (1 at.%), whereas the Fe addition (0.6 at.%) led to immediate failure after reaching the elastic limit. Plasticity is not reflected by the high Poisson's ratio of 0.4 since it remained unaffected by minor alloying. Applying the fictive temperature concept to analyze the impact of minor alloying suggests that the total amount of free volume frozen-in during vitrification is less important for the mechanical properties of bulk metallic glasses than its local distribution. (c) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.