Instabilities of interfaces between dissimilar metals induced by high pressure torsion
Instabilities of interfaces between dissimilar metals induced by high pressure torsion
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DOI：
10.1016/j.matlet.2018.03.200
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发表时间：
2018-07-01
影响因子：
3
通讯作者：
Hahn, H.
中科院分区：
文献类型：
--
作者：
Kulagin, R.;Beygelzimer, Y.;Hahn, H.
我们观察到双金属层合板的高压扭转(HPT)会导致层的涡旋状折叠不稳定性。因此，HPT导致垂直于砧座轴线的多尺度漩涡。这些不稳定性类似于金属表面在滑动过程中的折叠和HPT的同轴漩涡。HPT诱导的涡旋型不稳定性与流体中的Kelvin-Helmholtz流动不稳定性非常相似。我们在这项工作中证明了这种相似性只是显而易见的，而HPT引起不稳定性的物理原因与液体中的主要原因是不同的。我们用有限元模拟表明，金属层的折叠和涡动是由剪切变形的局部阻塞引起的塑性不稳定性所驱动的。因此，层状样品的HPT导致了变形过程中材料中涡旋的多尺度运动。这些运动类似于液体和气体的湍流，但它们具有完全不同的物理性质。(C)2018爱思唯尔B.V.保留所有权利。
We observed that high pressure torsion (HPT) of a bi-metallic laminate can induce vortex-like folding instabilities of layers. Thus, HPT leads to multiscale swirls which are perpendicular to the anvil axis. These instabilities are similar to folding of metallic surfaces during sliding and to co-axial swirls by HPT. The HPT induced vortex-like instabilities look very similar to the Kelvin-Helmholtz-type flow instabilities in fluids. We demonstrate in this work that this similarity is only apparent, and physical reasons for HPT-induced instabilituies are principally different from those in liquids. We show using finite element simulations that the folding and vortices of metallic layers are driven by plastic instabilities due to local blocking of shear deformation. Thus, HPT of layered samples leads to the multiscale movement of vortices in the material during deformation. These movements resemble turbulent flow of liquids and gases, but they have a completely different physical nature. (C) 2018 Elsevier B.V. All rights reserved.