Comparison of mechanical response in CuZrAl-V and CuZrAl-Co bulk metallic glass composites

Vanadium or cobalt up to 10 at% is alloyed to CuZrAl amorphous alloys to induce precipitation in order to form the bulk metallic glass composites. The heat of mixing between V or Co with respect to the base Cu element is positive. Microstructures and mechanical response of these two alloy systems are examined and compared. The V-rich second phase formed during rapid cooling possesses a sharp dendrite shape, inducing stress concentration in the amorphous matrix and lowering the mechanical performance. The Co-rich phase, formed from liquid phase separation, possesses round morphology, lowering the stress concentration and raising or sustaining the mechanical properties.