Metals (Feb 2021)

Negative Strain Rate Sensitivity Induced by Structure Heterogeneity in Zr<sub>64.13</sub>Cu<sub>15.75</sub>Ni<sub>10.12</sub>Al<sub>10</sub> Bulk Metallic Glass

  • Xiang Wang,
  • Zhi Qiang Ren,
  • Wei Xiong,
  • Si Nan Liu,
  • Ying Liu,
  • Si Lan,
  • Jing Tao Wang

DOI
https://doi.org/10.3390/met11020339
Journal volume & issue
Vol. 11, no. 2
p. 339

Abstract

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The negative strain rate sensitivity (SRS) of metallic glasses is frequently observed. However, the physical essence involved is still not well understood. In the present work, small-angle X-ray scattering (SAXS) and high-resolution transmission electron microscopy (HRTEM) reveal the strong structure heterogeneity at nanometer and tens of nanometer scales, respectively, in bulk metallic glass (BMG) Zr64.13Cu15.75Ni10.12Al10 subjected to fully confined compression processing. A transition of SRS of stress, from 0.012 in the as-cast specimen to −0.005 in compression processed specimen, was observed through nanoindentation. A qualitative formulation clarifies the critical role of internal stress induced by structural heterogeneity in this transition. It reveals the physical origin of this negative SRS frequently reported in structurally heterogeneous BMG alloys and its composites.

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