Mechanical properties of porous bulk glassy alloy prepared in high-pressure hydrogen atmosphere

Bulk glassy Pd_42.5Cu₃₀Ni_7.5P₂₀ (numbers indicate at.%) alloy rods containing fine spherical pores with the volume fraction less than 6% were prepared by a water quenching technique in high-pressure hydrogen atmosphere. The distribution of the pore is quite uniform in both transverse and longitudinal cross-section of the porous alloy rods. In compression deformation mode, the porous alloys have slightly low-yield strength compared with pore-free one and exhibit large plastic strain exceeding 18%. These results indicate that the introduction of small volume fraction of pores is effective to enhance the plasticity without much degradation of its mechanical strength. The beneficial effect of the pores comes from their action as powerful stress concentrators, forcing shear-band proliferation below the failure stress.