A combined experimental and computational analysis on how material interface mediates plastic flow in amorphous/crystalline composites
A combined experimental and computational analysis on how material interface mediates plastic flow in amorphous/crystalline composites
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DOI：
10.1557/s43578-021-00269-4
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发表时间：
2021-06
影响因子：
2.7
通讯作者：
Amir Abdelmawla;T. Phan;Liming Xiong;A. Bastawros
中科院分区：
文献类型：
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作者：
Amir Abdelmawla;T. Phan;Liming Xiong;A. Bastawros
本文通过纳米压痕实验和分子动力学模拟研究了非晶/晶态金属复合材料（A/C-MCs）的变形行为。研究了在非晶-晶界面（ACI）附近的晶相（C-）和非晶相（A-）中的原子变形过程，并将其与材料在微观尺度上的整体本构行为相关联。我们的主要发现是：（i）ACI通过不同的微观机制使A/C-MC中的软相“硬化”而硬相“软化”，从而使A相和C相共同变形;（ii）存在厚度约为10 nm的ACI诱导过渡区;（iii）剪切转变区（STZ）和位错之间的强耦合可以通过精心设计的压痕实验和模拟来量化;和（iv）纳米尺度MD模拟预测的机制可以映射到从微尺度实验提取的力-压痕深度曲线上的“弹出”或“偏移”事件，尽管两者之间存在长度尺度差距。
In this work, we study the deformation behavior in amorphous/crystalline metallic composites (A/C-MCs) through nanoindentation experiments and molecular dynamic (MD) simulations. The atomic deformation processes in both crystalline (C-) and amorphous (A-) phases near the amorphous-crystalline interface (ACI) are investigated and correlated with the material’s overall constitutive behavior at the microscale. Our major findings are (i) the ACIs enable a co-deformation of the A- and C-phases through “stiffening” the soft phases but “softening” the stiff phases in A/C-MCs through different micro-mechanisms; (ii) there exists an ACI-induced transition zone with a thickness of ~ 10 nm; (iii) the strong coupling between shear transformation zones (STZs) and dislocations can be quantified through carefully designed indentation experiments and simulations; and (iv) the nanoscale MD-simulation-predicted mechanisms can be mapped to the “pop-in” or “excursion” events on the force–indentation depth curves extracted from microscale experiments, although there is a length-scale gap in between.