Mechanics of Ultra-Strength Materials

Recent experiments on nanoscale materials, Including nanowires, nanopillars, nanoparticles, nanolayers, and nanocrystals, have revealed a host of ultra-strength phenomena, defined by stresses in the material generally rising up to a significant fraction of the ideal strength-the highest achievable strength of a defect-free crystal. This article presents an overview of the strength-controlling deformation mechanisms and related mechanics models in ultra-strength nanoscale materials. The critical role of the activation volume Is highlighted in understanding the deformation mechanisms, as well as the size, temperature, and strain rate dependence of ultra strength.