Structural instability and transformations in amorphous metals studied by mechanical spectroscopy

Mechanical spectroscopy of a quasi-static or dynamic type has been employed to study some aspects of structural stability in amorphous metals. Experimental results were obtained by internal friction and stress relaxation measurements on various alloys, both on different metastable states and submitted to specific mechanical treatments. The mobility, interaction, generation and annihilation of structural defects are at the origin of the permanent and reversible microstructural transformation observed. Reversible ordering phenomena associated with shear-type defects, irreversible mechanically induced defect annihilation and a transition between different amorphous structures are reported.