This project is a collaborative inter-disciplinary research to elucidate and model the deformation and fracture mechanisms of nanostructured materials. These studies are important for the reliability of next-generation MEMS, NEMS, magnetic and ultra-hard films, and micro/nano devices, in general, that are closely tied to their mechanical performance. A major objective is to obtain a thorough and solid understanding of operative deformation mechanisms operative in nanoscale materials. The study is specifically designed to probe the mechanical response of materials at nano-scales. Novel designs for in situ TEM observations and microsample tensile and transient experiments will be used to uncover and characterize the dominant deformation and fracture mechanisms in high purity vapor and electro-deposited nanostructured thin films. Multi-scale finite element calculations containing physical models will be developed based on the experimental findings. These models along with adaptive meshing and cohesive elements with atomistic descriptions of grain boundaries in nanocrystalline materials will be used to develop models to predict the collective macroscopic response of a compilation of nanocrystalline grains. The undergraduate and graduate students and post-doctoral fellows engaged in this project would be co- advised. Two parallel teams, each including a post-doc, graduate student and an undergraduate research assistant, will be formed and mentoring skills will be developed at all levels.
The overriding intellectual challenge of the proposed study is to develop a science based methodology for measuring, describing and modeling deformation and fracture processes at or near nanometer length scales. The results will have application in MEMS, NEMS and other technologies where magnetic and ultra-hard films are used. This project brings together a synergistic combination of expertise on the synthesis of nanocrystalline materials, the electron microscopy, microsample testing, and adaptive meshing and cohesive element modeling. The importance of teamwork is emphasized and all participants will be educated to work in an inter-disciplinary multi-scale environment at the nano scale.
