[SY-K3] Symposium K-3

[SY-K3] Temperature dependent shear friction in metallic glass

^○Akio Ishii¹, Tomoaki Niiyama², Takahiro Hatano³, Tomotsugu Shimokawa², Shigenobu Ogata¹ (1.Osaka Univ., Japan, 2.Kanazawa Univ., Japan, 3.Tokyo Univ., Japan)

Sharp local sliding such as shear band is frequently observed in bulk metallic glass subject to mechanical loading, and it usually leads to a global mechanical instability and then a catastrophic failure of metallic glass. Although sliding induced frictional force is a key to understand the stability of metallic glass, the details has not been fully clarified yet. Using a micromechanics-based kinetic Monte Carlo tensile test simulation of metallic glass [1], we computed a temperature and velocity dependent shear frictional force in metallic glass in experimental time scale. We found a negative velocity dependency (velocity weakening) within certain temperature range and thus a velocity dependency transition from negative to positive (velocity hardening) at a transition temperature as the temperature increases. The similar trend has been observed in rock as well [2].

[1] P. Zhao, et al., International Journal of Plasticity, 40 pp.1-22 (2013).

[2] C H. Scholz, nature, 391 pp.37-42 (1998).