Crystal Plasticity on the Nano and Micro Scales: Micromechanical Theory and Experiments

摘要：纳米和微米尺度上的晶体塑性。微机械理论与实验.PI：S.DJ.华盛顿州立大学机械与材料工程学院梅萨罗维奇提出了一项关于小体积位错塑性的基础研究。这项拟议的研究将协调实验、离散位错(DD)模拟以及以实验和离散位错模拟为指导的细观力学连续统理论的发展和实施。理论与实验之间，以及连续介质理论与其微观力学基础(位错力学)之间的现有鸿沟将被弥合。除了最近进行的楔形微压痕外，薄膜的约束剪切还将与随后的晶格旋转、晶格曲率和几何必要位错密度的OIM测量一起进行。通过建立基于位错力学的连续介质理论的严格热力学基础。这将使实验结果和离散位错模拟得到明确的连续解释。设想的研究计划与密歇根州立大学西苏里州立大学的研究生和本科生教育相结合。

ABSTRACT: Crystal Plasticity on the Nano and Micro Scales. Micromechanical Theory and Experiments.PI: S. Dj. Mesarovic, School of Mechanical and Materials Engineering, Washington State UniversityA fundamental study of dislocation plasticity in small volumes is proposed. The proposed study will coordinate experiments, discrete dislocation (DD) simulations, and, development and implementation of a micromechanical continuum theory guided by experiments and DD simulations. The existing gaps - between theories and experiments, and, between a continuum theory and its micromechanical foundation (dislocation mechanics), will be closed.The experiments on simple two-dimensional geometries with small number of active slip systems are proposed. In addition to the recently performed wedge microindentation, the constrained shear of a thin film will be performed with subsequent OIM measurements of lattice rotations, lattice curvature and densities of geometrically necessary dislocations.By developing a rigorous thermodynamic foundation of the continuum theory based on dislocation mechanics. This will enable unambiguous continuum interpretation of experimental results and of discrete dislocation simulations.The envisioned research program is integrated with graduate and undergraduate education at MME/WSU.