Interface-mediated shear behavior of bonded aluminum substrates
Interface-mediated shear behavior of bonded aluminum substrates
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DOI：
10.1007/s10853-022-07926-x
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发表时间：
2022-11
影响因子：
4.5
通讯作者：
Milad Khajehvand;H. Seppänen;Panthea Sepehrband
中科院分区：
文献类型：
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作者：
Milad Khajehvand;H. Seppänen;Panthea Sepehrband
采用分子动力学模拟方法研究了铝合金界面的剪切变形行为。在基体间存在取向差的情况下，当施加剪切力时，（111）取向的体系表现出无阻力滑动，而在（001）和（110）取向的体系中，源于界面位错网络的位错增殖（DM）被发现是控制机制。据观察，通过减小取向差角或增加垂直于界面的应变（JC的结果），发生更多DM。（110）取向的系统是最容易发生DM的系统，这是由于界面上存在Burgers矢量为α的位错< 100 >。最后，利用平均原子体积沿着垂直于界面方向的分布，定义了两个表征参数：界面体积膨胀（IVE）和界面厚度（IT）。IVE描述了界面处相对于本体中的过量自由原子体积，IT是被认为是界面区域（缺陷集中的地方）的系统部分的估计。IVE和IT被证明有一个反向和直接的关系，系统的剪切强度，分别，因此被引入作为新的工具预测剪切变形行为。IVE和IT参数的计算能够将界面的微观特性与剪切变形行为联系起来，这是各种应用中的控制现象。特别是，IT参数被发现是非常有前途的IT和剪切强度之间的直接关系被证明是独立的界面平面的取向。
Molecular dynamics simulations are utilized to study the shear deformation behavior of aluminum interfaces formed through jump-to-contact (JC) mechanism. In the presence of misorientation between substrates, when shear is applied, (111)-oriented systems exhibit resistance-free sliding, whereas in the (001)- and (110)-oriented systems, dislocation multiplication (DM), which originates from the network of interfacial dislocations, is found to be the controlling mechanism. It is observed that by a decrease in the misorientation angle or an increase in the strain normal to the interface (a consequence of JC), more DM occurs. (110)-oriented systems are found to be the most prone system to DM due to the existence of dislocations with Burgers vector of a < 100 > in their interface. Ultimately, using the profile of average atomic volume along the direction perpendicular to the interface, two characterizing parameters are defined: interface volume expansion (IVE) and interface thickness (IT). IVE describes the excess free atomic volume at the interface relative to that in the bulk, and IT is an estimate of the portion of the system that is considered as the interface region (where defects are concentrated). IVE and IT are shown to have a reverse and direct relationship with the shear strength of the system, respectively, and therefore are introduced as new tools for prediction of shear deformation behavior. Calculation of the IVE and IT parameters enables linking the microscopic characteristics of the interface to shear deformation behavior, which is a controlling phenomenon in various applications. Particularly, the IT parameter is found to be very promising as the direct relationship between IT and shear strength is shown to be independent of the orientation of the interface plane.