CHEMICAL STRUCTURAL RELAXATION-INDUCED EMBRITTLEMENT IN AMORPHOUS MG-CU-Y ALLOYS

Annealing-induced embrittlement of Mg-Cu-Y amorphous ribbons was evaluated by bend testing and differential scanning calorimetry. Two embrittlement parameters, i.e., the onset temperature of embrittlement, T(B), and the minimum amount of enthalpy relaxation leading to embrittlement, DELTAH(B), are sensitive to the alloy composition. T(B) and DELTAH(B) decrease with increasing Cu and Y content. It is presumed that relaxation-induced embrittlement was a consequence of the chemical short-range ordering between M and Cu or Y atoms.