Prominent plasticity of Mg-based bulk metallic glass composites by ex-situ spherical Ti particles

Mg58Cu28.5Gd11Ag2.5 bulk metallic glass composites (BMGCs) dispersion strengthened by spherical Ti particles with different volume fractions and particle sizes were synthesized by injection casting and characterized. The presence of spherical Ti particles could highly absorb the energy of shear banding and branch the primary shear band into multiple shear bands, thus decrease the stress concentration for further propagation of shear band and so as to significantly enhance plasticity. In addition, owing to the good bonding of interface between Ti particle and amorphous matrix, the yield strength can be kept at 800 MPa as increasing the addition of Ti particles to 40 vol.%. Additionally, It was found for a given volume fraction of Ti particles, smaller particles would lead to shorter interparticle spacings, smaller confinement zone sizes than the larger particles, and consequently improve the compression plasticity from 12% plastic strain (for the BMGC with Vf = 40% and particle size (D) = 89 ± 20 μm) up to 25% strain (for the BMGC with Vf = 40% and D = 50 ± 17 μm).Also, for a given Ti particle size, higher volume fraction would lead to larger compression plasticity. The interparticle spacing as well as the confinement zone size appears to be an effective factor in affecting the plasticity of BMGCs.