Low-density Mg-rich metallic glasses with bending ductility

Amorphous Mg–Cu–Ca(Y) alloys that contain more than 80 at.% magnesium and have a density as low as 1.8 g cm−3 have been prepared by melt spinning. Tension fracture strengths of ∼570 MPa are obtained for Mg85Cu5Ca10 ribbons, resulting in a specific strength of 300 MPa cm3 g−1. Scanning electron microscopy studies reveal dense river patterns on the fracture surface. The high Mg content and the thermal transformation behavior of these amorphous light alloys invite comparison to the Al-based metallic glasses.