| The effect of partial crystallization on the mechanical properties of a zirconium based bulk metallic glass is investigated in the glass transition interval. The viscoplastic and viscoelastic properties are studied using compression tests and mechanical spectroscopy. Partial crystallization results in an hardening effect in both viscoplasticity (i.e. increase of the viscosity for a given strain rate) and viscoelasticity (i.e. decrease of the loss modulus and increase of the storage modulus) indicating a decrease in atomic mobility. The shapes of both the viscosity / strain rate curves and of the DMA curves are merely the same whatever the investigated crystal amount. However, the apparent activation energy is decreasing as far as crystallisation occurs suggesting possible changes in the mechanisms of viscoelastic and/or viscoplastic deformation. |
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