Metallurgical and Materials Engineering Department, National Institute of Technology Rourkela, Rourkela, 769008, India.
J Mol Model. 2023 Mar 27;29(4):112. doi: 10.1007/s00894-023-05518-3.
Molecular dynamics-based investigation has been carried out to simulate the nano-indentation loading in crystalline Al-amorphous AlSm metallic glass (MG) with an aim to investigate the effect orientation of crystalline-amorphous (C/A) interface orientation on the nano-indentation behavior of the C/A Al-AlSm nanolaminate for varying indenter speeds. Post-analysis techniques like adaptive-common neighbor analysis (a-CNA), atomic strain, dislocation extraction algorithm (DXA), and Voronoi polyhedral analysis (VP) have been employed to capture the structural evolution during simulated nano-indentation loading. C/A Al-AlSm nanolaminate with C/A interface orientated perpendicular to the indenter exhibits the presence of elastic regime followed by plastic curve, whereas load versus depth curve behaves plastically since the beginning in case of C/A Al-AlSm nanolaminate with C/A interface orientated parallel to the indenter. The dislocation density growth is slower in case of C/A Al-AlSm nanolaminate with C/A interface orientated perpendicular to the indenter attributed to the sinking of dislocations into MG counterpart of the nanolaminate, thereby triggering shear transformation zone activation. Whereas, the dislocation generation is delayed in case of C/A Al-AlSm nanolaminate with C/A interface orientated parallel to the indenter by virtue of amorphous AlSm MG coating on crystalline Al but is extensive and rapid. The disintegration of ICO-like structures and mixed clusters and growth of crystal-like clusters is discernible in C/A Al-AlSm nanolaminate with C/A interface orientated perpendicular to the indenter. On the other hand, the VP population exhibits cyclic variation in C/A Al-AlSm nanolaminate with C/A interface orientated parallel to the indenter. A transformation pathway of VPs has been mapped out for C/A Al-AlSm nanolaminate under nano-indentation loading.
The simulations have been carried out by employing Molecular Dynamics using the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) platform. Post-analysis techniques like adaptive-common neighbor analysis (a-CNA), atomic strain, dislocation extraction algorithm (DXA), and Voronoi polyhedral analysis (VP) have been employed to capture the structural evolution during simulated nano-indentation loading.
为了研究晶-非晶（C/A）界面取向对不同压入速度下 C/A Al-AlSm 纳米层压板纳米压痕行为的影响，采用基于分子动力学的方法对具有 C/A 界面取向的晶态 Al-非晶态 AlSm 金属玻璃（MG）进行了纳米压痕加载模拟。自适应公共邻居分析（a-CNA）、原子应变、位错提取算法（DXA）和 Voronoi 多面体分析（VP）等后分析技术已被用于捕获模拟纳米压痕加载过程中的结构演变。C/A 界面垂直于压头的 C/A Al-AlSm 纳米层压板表现出弹性阶段，随后是塑性曲线，而 C/A 界面平行于压头的 C/A Al-AlSm 纳米层压板的载荷与深度曲线从开始就表现出塑性。由于位错沉入纳米层压板的 MG 对应物，从而引发剪切转变区的激活，因此 C/A 界面垂直于压头的 C/A Al-AlSm 纳米层压板的位错密度增长较慢。而由于非晶态 AlSm MG 涂层位于晶态 Al 之上，因此 C/A 界面平行于压头的 C/A Al-AlSm 纳米层压板的位错生成延迟，但扩展迅速。在 C/A 界面垂直于压头的 C/A Al-AlSm 纳米层压板中，可以分辨出 ICO 样结构和混合团簇的解体以及晶体状团簇的生长。另一方面，在 C/A 界面平行于压头的 C/A Al-AlSm 纳米层压板中，VP 种群表现出周期性变化。已经为纳米压痕加载下的 C/A Al-AlSm 纳米层压板映射出了 VP 的转变途径。
通过使用大型原子/分子大规模并行模拟器（LAMMPS）平台的分子动力学进行了模拟。自适应公共邻居分析（a-CNA）、原子应变、位错提取算法（DXA）和 Voronoi 多面体分析（VP）等后分析技术已被用于捕获模拟纳米压痕加载过程中的结构演变。
