Well-known for its high yield strength, metallic glass often suffers from its low ductility and intrinsic brittleness, as discussed in a recent iMech jClub theme on plasticity and failure in metallic glasses led by Yanfei Gao.

Prof. William L. Johnson 's group in Caltech recently demonstrated a new design of metallic glass with significant increase in tensile ductility, by adding crystalline inclusions. For example, the tensile ductility is increased typically to more than 10%, and fracture
toughness is enhanced to the extent comparable to titanium or steel alloys.  Their research has recently been published in Nature.

Hofmann et al., Nature (2008) 451, 1085-1089.