Understanding of micro-alloying on plasticity in Cu46Zr47-xAl7Dyx (0≤x≤8) bulk metallic glasses under compression: Based on mechanical relaxations and theoretical analysis
Understanding of micro-alloying on plasticity in Cu46Zr47-xAl7Dyx (0≤x≤8) bulk metallic glasses under compression: Based on mechanical relaxations and theoretical analysis
复制标题
微合金化对 Cu46Zr47-xAl7Dyx (0≤x≤8) 大块金属玻璃压缩塑性的影响：基于机械松弛和理论分析
DOI：
10.1016/j.ijplas.2016.02.002
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发表时间：
2016
影响因子：
9.8
通讯作者：
L.M. Keer
中科院分区：
文献类型：
--
作者：
J.C. Qiao;Y. Yao;J.M. Pelletier;L.M. Keer
大块金属玻璃在常温下缺乏塑性严重阻碍了其广泛应用，而提高其塑性是一个重大的挑战。根据金相物理原理，微合金化可以用来调节金属玻璃的塑性。本文采用动态力学分析的方法，对Cu46Zr47−xAl7Dyx(0，≤，x，≤，8)大块金属玻璃的动态力学松弛进行了实验研究。通过压缩试验研究了铜基大块金属玻璃在常温和低温下的力学性能。结果表明，通过改变化学成分，改变了合金的塑性变形和动态力学松弛过程。Dy对塑性变形的影响可能与金属玻璃中的Johari-Goldstein(JG)弛豫有关。一个可以预测金属玻璃的力学松弛行为和原子迁移率的动力学模型。此外，实验分析表明，Dy的加入对铜基大块金属玻璃的热性能有一定的影响。研究表明，Dy的微合金化对Cu46Zr47−xAl7Dyx大块非晶合金的塑性有重要影响。为了解释这一现象，用准点缺陷理论描述了这种微观结构的非均质性。我们假设压缩塑性与金属玻璃的局域非均匀和弛豫模直接相关。
Lacking of plasticity at ambient temperature severely hinders the wide applications of bulk metallic glasses, and a significant challenge is to improve the plasticity. Based on the metallurgical physics, micro-alloying can be applied to adjust metallic glasses plasticity. In the current work, dynamic mechanical relaxation of Cu46Zr47−xAl7Dyx(0 ≤ x ≤ 8) bulk metallic glasses has been investigated experimentally by dynamic mechanical analysis. Compressive tests have been performed to investigate mechanical properties of the Cu-based bulk metallic glasses at both ambient as well as cryogenic temperatures. The results indicated that by modifying the chemical composition, plastic deformation and dynamic mechanical relaxation processes are changed. The influence of Dysprosium (Dy) on plastic deformation is possibly related to the Johari-Goldstein (JG) relaxation in the metallic glasses. A kinetic model which may be predict the mechanical relaxation behavior and atomic mobility of the metallic glasses. In addition, experimental analyses show that thermal properties can be affected by the Dy addition of the Cu-based bulk metallic glasses. Our investigations demonstrated that micro-alloying of Dy could play an important role to influence the Cu46Zr47−xAl7Dyxbulk metallic glasses plasticity. In order to explain this behavior, the quasi-point defects theory was used to describe the microstructural heterogeneity. We postulate that the compressive plasticity is directly associated with local heterogeneity and relaxation modes for metallic glasses.