Dislocation-Based Deformation Mechanisms in Metallic Nanolaminates: An Experimental and Theoretical Study

这项工作涉及位错力学建模与新型加工和透射电子显微镜实验之间的密切研究互动，这将导致对层状纳米材料变形机制的基本理解。本研究的一个主要目标是了解这些材料在塑性变形时的极限强度，因为结构中各个层的厚度减少到纳米尺度。为了做到这一点，研究人员将直接观察层状纳米材料中位错的产生、运动和相互作用。将特别注意界面不再能够将位错运动限制在单个层的临界条件。这些观察结果将与限制层几何形状中位错成核和运动的理论处理以及传递滑移穿过晶界和界面的临界应力密切相关。这项研究将通过相的选择、它们的使用尺度、界面结构和限制位错运动的晶界来扩展我们如何开发超高强度两相层状纳米材料的知识

0072010AndersonThis effort involves a close research interaction between dislocation mechanics modeling and novel processing and transmission electron microscrope experiments that will lead to a fundamental understanding of deformation mechanisms in layered nanomaterials. A principal goal of this research is to understand the limiting strength of such materials to plastic deformation, as the thickness of individual layers in the structure are decreased to the nanometer scale. To do so, the investigators will observe directly the generation, motion, and interaction of dislocations in layered nanomaterials over a range of individual layer thickness. Particular attention will be given to the critical conditions for which interfaces are no longer able to confine dislocation motion to individual layers. These observations will couple closely with theoretical treatments of the nucleation and motion of dislocations in confined layer geometries, and the critical stress to transmit slip across grain boundaries and interfaces. This research will extend our knowledge of how to develop ultra-high strength two-phase layered nanomaterials through the choice of phases, the scale at which they are employed, and the structure of the interfaces and grain boundaries which serve to confine dislocation motion.***