Oxygen effects on plastic deformation of a Zr-based bulk metallic glass

Starting with Zr of two different purities, Zr-based bulk metallic glasses (BMGs) with a nominal composition of Zr62Cu15.5Ni12.5Al10 were prepared having oxygen concentrations of about 3900 and 920at.ppm, respectively. Uniaxial compression tests showed that the BMG containing the higher level of oxygen has a higher yield strength and is capable of undergoing much less plastic deformation than that containing the lower level of oxygen. It appears that oxygen suppresses the formation of multiple shear bands but leads to an inability to sustain shear-band propagation, thus, changing the failure mode from relatively ductile to catastrophic brittle fracture.