Serration and shear avalanches in a ZrCu based bulk metallic glass composite in different loading methods

Haichao Sun¹，Zhiliang Ning¹，Jingli Ren²，Weizhong Liang³，Yongjiang Huang¹，Jianfei Sun¹，Xiang Xue¹，Gang Wang⁴

1. School of Materials Science and Engineering, Harbin Institute of Technology2. School of Mathematics and Statistics, Zhengzhou University3. School of Materials Science and Engineering, Heilongjiang University of Science and Technology4. Laboratory for Microstructures, Institute of Materials, Shanghai University

摘 要：In the current research, serrated flow is investigated under tensile and compressive loading in a Zr Cubased bulk metallic glass composite（BMGC） that is well known for its plastic deformability, which is higher than that of metallic glasses. Statistical analysis on serrations shows a complex, scale free process,in which shear bands are highly correlated. The distribution of the elastic-energy density stored in each serration event follows a power-law relationship, showing a randomly generated serrated event under both tension and compression tests. The plastic deformation in the temporal space is explored by a timeseries analysis, which is consistent with the trajectory convergent evolution in critical dynamic behavior even in the low strain rate regime in both tests. The results demonstrate that the secondary phase in the BMGC can stabilize the shear band extension and facilitate the critical behavior in the low strain rate regime. This study provides a strong evidence of serrated flow phenomenon in BMGC under tension test,and offers a deep understanding of the correlation between serrations and shear banding in temporal space.

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