Shear band spacing under bending of Zr-based metallic glass plates

Metallic glasses often exhibit marked ductility when subjected to compressive or bending loads as a result of multiple shear band formation. This observed ductility depends upon sample geometry; thin plates show ductility in bending while thicker plates of the same composition fracture under similar loading. The thickness dependence of yielding and fracture of metallic glass plates subjected to bending is considered in terms of the shear band processes responsible for these properties. Experimental results show that shear band spacing and length scale with the thickness of the plate at a ratio of 1:10. Both shear band offset and shear band spacing increase with increasing curvature; shear band offset as the square of the plate thickness. As bending is increased beyond yield, shear band spacing continues to increase until the strain is accommodated by a few long shear bands. Continued bending leads to crack formation and failure.