Wepresent first-principles simulations of single grain boundary reflectivity of electrons in noble metals, Cu and Ag. We examine twin and non-twin grain boundaries using nonequilibrium Green’s function and first principles methods. We also investigate the determinants of reflectivity in grain boundaries by modeling atomic vacancies, disorder, and orientation and find that both the change in gra...

Abstract By analyzing the degree of grain deformation FGH96 alloy under different plastic process parameters, as well relative frequency and distribution characteristics recrystallized core boundaries with orientation differences, comprehensively considering evolution law grains sizes, relationship between boundary is studied. The correlation nucleation mechanism grains, growth cores, related d...

As characteristic length scales shrink (<100 nm) in fcc metals, alternative deformation mechanisms not seen in bulk and course-grained material counterparts emerge. In particular in grain sizes on the order of 10s of nanometers, plasticity is mediated by the motion and interaction of partial dislocations and extended stacking faults. Typically, partial dislocations nucleate at grain boundary de...

High temperature nanoindentation experiments are conducted to assess the activation enthalpy for deformation of nanocrystalline Ni-W alloys, for grain sizes between 3 and 80 nm. Thermal softening becomes less pronounced at finer grain sizes, and the activation enthalpy has an apparent inflection at a grain size near ~10-20 nm, in the vicinity the Hall-Petch breakdown. This inflection is related...

In this paper, a multiscale modelling strategy is used to study the effect of grain-boundary sliding on stress localization in a polycrystalline microstructure with an uneven distribution of grain size. The development of the molecular dynamics (MD) analysis used to interrogate idealized grain microstructures with various types of grain boundaries and the multiscale modelling strategies for mod...

To achieve higher fatigue resistance against subsurface crack generation, both the refinement of grain structure and the introduction of mobile dislocations on various slip systems have been shown to be effective in the 32Mn-7Cr austenitic steel. A novel treatment which consisted of cold grooved rolling and partial recrystallization was introduced to modify the microstructure. High-cycle fatigu...