Embrittlement of metallic glasses is referred to as the degrading of ductility or toughness, typically related to annealing. Fundamentally there are two different origins for embrittlement of metallic glasses, one is occurring below its glass transition temperature and is related to structural relaxation of the amorphous phase towards a more (meta)stable denser glass phase, and the other occurs above the glass transition temperature. Here crystallization causes embrittlement. Our research is concerned about the influence of processing on the mechanical properties and targets to quantify these effects. Furthermore we try to understand the difference in the embrittlement kinetics and magnitude of the degradation among metallic glasses.
Embrittlement as function of annealing time. For this Zr-Ti-Ni-Cu-Be alloy severe embrittlement sets in at after about one hour at 310°C. The original ductile characteristic of this alloy can be reestablished when heating at any annealing time above the glass transition temperature (from B to D).