Molecular dynamics studies of the interaction of a/6 112 Shockley dislocations with stacking fault tetrahedra in copper. Part I: Intersection of SFT by an isolated Shockley
Molecular dynamics studies of the interaction of a/6 112 Shockley dislocations with stacking fault tetrahedra in copper. Part I: Intersection of SFT by an isolated Shockley
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DOI：
10.1080/14786430902740737
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发表时间：
2009-01-01
影响因子：
1.6
通讯作者：
Hoagland, R. G.
中科院分区：
文献类型：
--
作者：
Niewczas, M.;Hoagland, R. G.
用分子动力学方法研究了面心立方晶体中Shockley位错与孪生变形过程中形成的层错四面体(SFTS)的相互作用。运动的Shockley位错与SFT相互作用的基本机制包括剪切尖端，在SFT周围形成残余环，以及在四面体底部与位错发生反应。后一种反应对缺陷的稳定性至关重要；它们导致在母四面体的两个面上移动的Shockley位错的形成，使其在孪晶增厚期间能够穿透在相邻平面上移动的位错。文中还研究了均匀孪生剪切引起的SFT的弛豫。这些结果表明，母体SFT转变为含有旋转产物SFT、空位排和以部分位错为边界的[图像省略]面上的层错的结构。分析了Shockley-SFT相互作用中的位错机制以及双剪切SFT产生的新缺陷的形成。
The interactions of Shockley dislocations with stacking fault tetrahedra (SFTs) formed during twinning deformation in fcc crystals have been studied by molecular dynamics using a copper potential. The fundamental mechanisms by which a moving Shockley dislocation interacts with a SFT involve shearing the apex, formation of a residual loop around the SFT and reactions with dislocations at the tetrahedron base. The latter reactions are critical to defect stability; they lead to the formation of Shockley dislocations mobile in two faces of the parent tetrahedron making it penetrable to dislocations moving on adjacent planes during thickening of the twin. Relaxation of SFTs distorted by a homogeneous twinning shear was also studied. These results reveal that parent SFTs convert to structures containing rotated product SFTs, rows of vacancies and stacking faults on [image omitted] planes bounded by partial dislocations. Dislocation mechanisms involved in Shockley-SFT interactions and formation of new defects derived from twin-sheared SFTs are being analyzed.