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

0072010安德森这项工作涉及位错力学建模和新的加工和透射电子显微镜实验，将导致在层状纳米材料的变形机制的基本理解之间的密切研究相互作用。 这项研究的主要目标是了解这种材料的塑性变形的极限强度，因为结构中各个层的厚度减小到纳米级。 为了做到这一点，研究人员将直接观察分层纳米材料中位错的产生、运动和相互作用。 将特别注意的临界条件，界面不再能够限制位错运动到个别层。 这些观察将密切耦合的理论处理的成核和运动的位错在限制层的几何形状，和临界应力传输滑移越过晶界和界面。 这项研究将扩展我们对如何通过相的选择，使用它们的规模以及用于限制位错运动的界面和晶界的结构来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.***