Effect of cold rolling on compressive and tensile mechanical properties of Zr52.5Ti5Cu18Ni14.5Al10 bulk metallic glass

The effect of cold-rolling on structure, thermal stability, and compressive and tensile mechanical properties of the Zr52.5Ti5Cu18Ni14.5Al10 bulk metallic glass has been investigated. The results reveal that cold-rolling does not influence the thermal stability of the material. However, the small plastic deformation induced by cold-rolling is very effective for improving the room temperature plastic strain of the glass: the compressive plastic strain increases from 1.1% for the as-cast material to 2.6% for the cold-rolled sample and the tensile ductility increases from 0% for the as-cast glass to 0.8% for the cold-rolled sample. Hardness measurements indicate that cold rolling creates a heterogeneous microstructure consisting of hard and soft regions. Most likely, the soft regions are preferred locations for shear band formation and propagation, whereas the hard regions may act as obstacles for shear band propagation, effectively limiting shear bands from propagating catastrophically and, consequently, enhancing the room temperature plastic deformation of the glass. (C) 2011 Elsevier B. V. All rights reserved.