• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Role of interfaces on severe plastic deformation and He-irradiation tolerance in Cu-Nb nanocomposites.
【24h】

Role of interfaces on severe plastic deformation and He-irradiation tolerance in Cu-Nb nanocomposites.

机译：界面在Cu-Nb纳米复合材料中严重塑性变形和He辐射耐受性中的作用。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Interface structure in immiscible metal nanocomposites plays a key role in deformation tolerance and radiation damage tolerance. Interface structure, just like microstructure, can vary within the same material system depending on the processing route; the properties of a material can also vary depending on the interface structure. The role of interface structure on the tolerance to severe plastic deformation in Cu-Nb nanocomposites was investigated by comparing the microstructural evolution after high pressure torsion (HPT) of multilayer nanocomposites grown by physical vapor deposition (PVD) with low shear strength interfaces and fabricated by accumulative roll bonding (ARB) with high shear strength interfaces. And the role of interface structure on the trapping of He was studied by comparing He-bubble formation in nano-multilayers grown by PVD, nanolaminates fabricated by ARB, and three-dimensional nanocomposites obtained by high pressure torsion (HPT); each of these has a different preferred orientation relationship.;The stability of PVD-grown multilayers when subjected to HPT is significantly better to high shear strain than the ARB-fabricated multilayers. The PVD-grown multilayers remain largely stable up to a strain of ∼81 and still have regions of multilayers at a strain of ∼357 before transforming to a 3D nanocomposite by a strain of ∼685; the ARB multilayer composites meanwhile become unstable at shear strain of ∼10 and completely transform to a 3D interconnected composite at a strain of ∼278. The mechanisms for deformation depend on the interface character; the PVD-grown material with low shear strength interfaces deform by interfacial sliding while the ARB-fabricated material deforms by dislocation glide across the interface. In both layered systems, there is kink and shear banding of layers at higher shear strain that changes the local orientation of layers relative to the shear direction resulting in a route to transition to a 3D nanocomposite structure.;Likewise under He-ion irradiation, the critical He dose per unit interfacial area for bubble formation was largest for the PVD multilayers, lower by a factor of ∼1.4 in the HPT nanocomposites annealed at 500 °C, and lower by a factor of ∼4.6 in the ARB nanolaminates relative to the PVD multilayers. The high concentration of free volume at interfaces in PVD-grown multilayers is excellent for trapping He atoms and point defects, and the amount of trapped He at the interface scales with interface area density. A combination of efficient interfaces and high density of interfaces is ideal for trapping He atoms and point defects.;The results of both high shear strain using HPT and He implantation indicate that the (111)FCC||(110)BCC Kurdjumov-Sachs (KS), or {111}KS, interfaces predominant in PVD provide more effective traps for both point and line defects than the {112}KS interfaces predominant in ARB nanolaminates. The steady-state microstructural stability, good trapping efficiency, and high interface area of 3D structures processed by severe plastic deformation make them most attractive for structural applications such as nuclear energy.
机译：不混溶的金属纳米复合材料的界面结构在形变耐受性和辐射损伤耐受性中起着关键作用。界面结构就像微观结构一样，在同一材料系统中可能会根据加工路线而有所不同。材料的特性也可以根据界面结构而变化。通过比较物理气相沉积（PVD）和低剪切强度界面制造的多层纳米复合材料的高压扭转（HPT）后的微观结构演变，研究了界面结构对Cu-Nb纳米复合材料对严重塑性变形的耐受性的作用。具有高剪切强度界面的累积式辊压粘合（ARB）。并通过比较PVD生长的纳米多层膜，ARB制备的纳米层合物和高压扭转（HPT）获得的三维纳米复合材料中He气泡的形成，研究了界面结构对He的俘获作用；这些中的每一个具有不同的优选取向关系。； PVD生长的多层在经受HPT时的稳定性比ARB制造的多层明显好于高剪切应变。 PVD生长的多层膜在高达〜81的应变下仍保持较大的稳定性，并且在〜685的应变转变为3D纳米复合材料之前，仍具有约357的多层区域。同时，ARB多层复合材料在约10的剪切应变下变得不稳定，并在约278的应变下完全转变为3D互连复合材料。变形的机理取决于界面的特性。具有低抗剪强度界面的PVD生长材料会因界面滑动而变形，而ARB制造的材料会因位错滑移而在界面上变形。在这两个分层系统中，在较高的剪切应变下均存在层的扭结带和剪切带，从而改变了层相对于剪切方向的局部取向，从而导致了过渡到3D纳米复合结构的途径。相对于PVD，PVD多层膜每单位界面面积的临界He剂量最大，在500°C退火的HPT纳米复合材料中降低约1.4倍，在ARB纳米层压板中降低约4.6倍。多层。 PVD生长的多层中界面处的高自由体积浓度非常适合捕获He原子和点缺陷，并且界面处的He捕集量随界面面积密度的变化而变化。有效界面和高界面密度的组合非常适合捕获He原子和点缺陷。;使用HPT和He注入的高剪切应变的结果表明（111）FCC ||（110）BCC Kurdjumov-Sachs（与在ARB纳米层压板中占优势的{112} KS界面相比，PVD中占优势的KS）（或{111} KS）界面为点和线缺陷提供了更有效的陷阱。通过剧烈的塑性变形处理的3D结构的稳态微结构稳定性，良好的俘获效率和高界面面积，使其对于诸如核能之类的结构应用最有吸引力。

著录项

  • 作者

    Lach, Timothy Gerald.;

  • 作者单位

    University of Illinois at Urbana-Champaign.;

  • 授予单位 University of Illinois at Urbana-Champaign.;
  • 学科 Materials science.;Engineering.
  • 学位 Ph.D.
  • 年度 2016
  • 页码 101 p.
  • 总页数 101
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号