Temperature rise in shear bands in a simulated metallic glass

Abstract

Temperature rise (∆T ) associated with shear-banding of metallic glasses is of great importance for their performance. However, experimental measurement of ∆T is difficult due to temporal and spatial localization of shear bands and, as a result, our understanding of the mechanism of ∆T is limited. Here, based on molecular dynamics simulations we observe a spectrum of ∆T , which depends on both sample size and strain rate, in the shear bands of CuZr metallic glass under tension. More importantly, we find that the maximum sliding velocity of the shear bands correlates linearly with the corresponding ∆T , ranging from ∼25 K up to near the melting point for the samples studied. Taking heat diffusion into account, we expect ∆T to be lower than 25 K for the lower end of sliding velocity. At high temperature, shear band bifurcation and/or multiplication can occur as a negative feedback mechanism that prevents temperature rising well above the melting point.

Mechanical response of mesoporous amorphous NiTi alloy to external deformations

“…2(a)]. The slope of this linear part have weak dependence on the strain rate [51,52]. Note that the high elastic moduli will correspond to materials with more pronounced elasticity.…”

Effect of cutting speed on surface integrity and chip formation in micro-cutting of Zr-based bulk metallic glass

“…deformation, which generates a temperature change from 278 K to more than 1273 K [21]. According to the molecular dynamic simulation, an increase of temperature in the shear bands of CuZr metallic glass is correlated positively with the strain rate under tensile loading [22]. However, the molecular dynamic simulation results showed that the cutting temperature of Zr-50Cu30 metallic glasses can reach 600-700K in the nanoscale cutting process [23].…”

Temperature Rise Inside Shear Bands in a Simple Model Glass

“…However, it is rather difficult to experimentally and accurately access heat generation and temperature inside the bulk of material (i.e, away from surfaces), and one is thus often restricted to apply indirect methods and rough estimates. Indeed, reported values of in the existing literature are distributed over a broad range, differing sometimes by several orders of magnitude [ 7 , 12 , 13 , 14 , 15 , 16 , 17 ].…”