Atomistic study on simultaneous achievement of partial crystallization and rejuvenated glassy structure in thermal process of metallic glasses
Atomistic study on simultaneous achievement of partial crystallization and rejuvenated glassy structure in thermal process of metallic glasses
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DOI：
10.1080/14786435.2022.2048112
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发表时间：
2022-03
影响因子：
1.6
通讯作者：
M. Wakeda;J. Saida;T. Ichitsubo
中科院分区：
文献类型：
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作者：
M. Wakeda;J. Saida;T. Ichitsubo
弛豫状态和部分晶化是影响金属玻璃材料性能的重要因素。复原引起较不松弛的玻璃状态，因此促进松弛状态的控制。热加工过程中的再生和晶化与金属玻璃加热时的相变密切相关。大多数通过常规热退火形成的纳米晶金属玻璃具有松弛的玻璃基质。在分子动力学研究中，我们研究了热处理的可行性，同时实现部分结晶和再生模型合金系统。动态力学分析揭示了由晶相和再生玻璃基体组成的金属玻璃的弛豫行为和局部变形特征。结晶相在宽的温度范围内增加了复合材料模型的宏观剪切刚度，而它并不显著影响再生玻璃基质的内部摩擦。此外，分散的纳米晶体抑制了再生玻璃基质中尖锐和集中的剪切局部化的发展。本文从金属玻璃的微观结构设计的角度讨论了玻璃基体中弛豫态和晶相的同时调节。
ABSTRACT The relaxation state and partial crystallization are crucial factors that affect the material properties of metallic glasses. Rejuvenation induces a less relaxed glass state and hence facilitates the control of the relaxation state. The rejuvenation and crystallization during thermal processing are associated closely with the phase changes of metallic glasses upon heating. Most nanocrystalline metallic glasses formed via conventional thermal annealing have a relaxed glassy matrix. In this molecular dynamics study, we investigate the feasibility of thermal processing to simultaneously realise both partial crystallization and rejuvenation using model alloy system. Dynamic mechanical analyses reveal relaxation behaviours and local deformation features of metallic glasses composed of a crystalline phase and a rejuvenated glass matrix. The crystalline phase increases the macroscopic shear stiffness of the composite model over a wide temperature range, whereas it does not significantly affect the internal friction of the rejuvenated glass matrix. In addition, dispersed nanocrystals suppress the development of sharp and concentrated shear localisation in the rejuvenated glass matrix. The simultaneous adjustment of the relaxation state and crystalline phase in the glass matrix is discussed from a viewpoint of the microstructure design of metallic glasses.