Size-dependent failure mechanisms in ZrNi thin metallic glass films

 The fracture toughness of submicron Zr65Ni35 sputter-deposited films is thickness dependent. The failure mechanism involves corrugations for the thickest films and a transition—at 500 nm thickness—to a perfectly flat fracture surface. Both mechanisms are brittle-type, even though the elastic and plastic properties are independent of thickness and similar to the expected ductile bulk response. Finite-element simulations unravel the origin of the size effect and the transition of failure mode from the constraint on plastic dissipation.