Does the fracture toughness of bulk metallic glasses scatter?

A method is introduced to determine notch toughness of bulk metallic glasses (BMGs). Through thermoplastic replication of Si molds, unprecedented control in fabricating BMG toughness samples can be achieved and influences such as cooling rate, thermal history, residual stress, sample geometry, and notch precision are drastically reduced. For the 20 Zr44Ti11Cu10Ni10Be25 BMG samples, we measured a notch toughness of 109 ± 3 MPa m. Such a much smaller scatter than the previously reported suggests reliable properties of BMGs when thermoplastically formed.