Intrinsic factor controlling the deformation and ductile-to-brittle transition of metallic glasses

Abstract

The energetic driving force and resistance for shearing and cracking in metallic glasses (MGs) are quantitatively evaluated. A universal thermodynamic criterion is proposed for better understanding the intrinsic correlations between fracture toughness and Poisson’s ratio, the competitions between various deformation modes and the ductile-to-brittle transition in MGs and other materials. A new cooperation parameter δ is also introduced to depict quantitatively the relative propensity of shearing versus cracking. This work could provide insights into the long-standing issues of deformation mechanisms of glassy materials, and be helpful in searching for ductile and tough MGs.

Keywords:

• metallic glass
• thermodynamics
• Poisson’s ratio
• ductile-to-brittle transition
• shear bands

Additional information

Funding

Funding. This work was supported by the National Natural Science Foundation of China [grant number 50890173], [grant number 51331007]; the National Basic Research Program of China [grant number 2010CB631006]; the IMR SYNL-T.S. Kê Research Fellowship.