Plasticity improvement of a Zr-based bulk metallic glass by micro-arc oxidation

Mciro-are oxidation (MAO) was used to coat porous films on the surface of a Zr-based bulk metallic glass sample. The compressive test results indicated that, compared with the as-cast sample, the MAO treated one exhibited higher deformation capacity, associated with multiple shear bands with higher density on the side surface and well-developed vein patterns with smaller size on the fractured surface. The pore in the MAOed film and the matrix/coating interface initiated the shear bands and impeded the rapid propagation of shear bands, thus favoring the enhanced plasticity of the MAO treated sample. The obtained results demonstrated that MAO can be considered as an effective method to finely tune the mechanical performance of monolithic bulk metallic glasses.