Plasticity-improved Zr–Cu–Al bulk metallic glass matrix composites containing martensite phase

$Zr48.5Cu46.5Al5$ bulk metallic glass matrix composites with diameters of 3 and $4mm$ were produced through water-cooled copper mold casting. Micrometer-sized bcc based B2 structured CuZr phase containing martensite plate, together with some densely distributed nanocrystalline $Zr2Cu$ and plate-like $Cu10Zr7$ compound, was found embedded in a glassy matrix. The microstructure formation strongly depends on the composition and cooling rate. Room temperature compression tests reveal significant strain hardening and plastic strains of 7.7% and 6.4% before failure are obtained for the $3-mm$- and $4-mm$-diam samples, respectively. The formation of the martensite phase is proposed to contribute to the strain hardening and plastic deformation of the materials.