Fracture toughness of bulk metallic glass welds made using nanostructured reactive multilayer foils

We measured the fracture toughness of joints in amorphous Zr57Ti5Ni8Cu20Al10 made using Al/Ni reactive multilayer foils. The highest fracture toughness measured was ∼12 MPa m1/2. Based on the fracture toughness and the crack propagation paths, we conclude that virtually all of the toughness can be ascribed to the presence of metallic glass ligaments in the joint. Increasing the stress applied during joining increases the area fraction of these ligaments and so increases the fracture toughness as well.