Physical properties of bulk amorphous glasses: influence of physical aging and onset of crystallisation

Measurements of the dynamic shear modulus and of the internal friction are performed in a bulk amorphous Zr57–Ti5–Cu20–Ni8–Al10 (at.%) alloy, both during heating and cooling with different cooling rates and different frequencies. The kinetic aspect of the glass transition is demonstrated. The onset of the crystallisation process induces a modulus increase and an internal friction decrease, due to the decrease of the atomic mobility resulting from the crystallisation process. Experimental results are well described using a physical model of the mechanical response of the amorphous material and especially of the characteristic times of the atomic mobility.