A continuum model of nanocrystalline copper was developed based on results from independent atomistic calculations on 11 bicrystals containing high angle grain boundaries. The relationship between grain boundary structure and its mechanical response was investigated. Based on the atomistic calculations; a constitutive law for grain boundary interfaces was implemented within a finite element cal...

The recent results of the application of diffraction techniques to study the atomic structure of grain boundaries are reviewed. The outcome of the first determination of a grain boundary structure using diffraction information alone is examined. The influence of a particular metal on the grain boundary structure is examined. The variation of grain boundary structural width with parameters such ...

Recent experimental and computational studies have produced two large grain boundary energy data sets for Ni. Using these results, we perform the first large-scale comparison between measured and computed grain boundary energies. While the overall correlation between experimental and computed energies is minimal, there is excellent agreement for the data in which we have themost confidence, par...

The three-dimensional interfacial grain boundary network in a fully austenitic high-manganese steel was studied as a function of all five macroscopic crystallographic parameters (i.e. lattice misorientation and grain boundary plane normal) using electron backscattering diffraction mapping in conjunction with focused ion beam serial sectioning. The relative grain boundary area and energy distrib...

Cohesive laws are stress-strain curves used in finite element calculations to describe the debonding of interfaces such as grain boundaries. It would be convenient to describe grain boundary cohesive laws as a function of the parameters needed to describe the grain boundary geometry; two parameters in two dimensions and five parameters in three dimensions. However, we find that the cohesive law...

Grain boundaries exhibit phase-like behavior in which their structure, chemistry and properties may change discontinuously at critical values of thermodynamic parameters such as temperature, pressure and chemical potential. Therefore, grain boundaries (and other interfaces such as surfaces and heterophase boundaries) can be treated as thermodynamically stable interfacial states. To differentiat...

The Autonomous Basin Climbing method and Rate Theory are applied to investigate the interstitial emission mechanism in alpha-Fe. The atomic trajectories and potential energy landscape of the interstitial emission process induced by the S3<110>{111} symmetrical tilt grain boundary are presented. By comparing with vacancy hopping mechanism, the grain boundary influence range at finite temperature...

Measurements of the elastic constants,the specific heat and the entropy of grain boundaries have been performed by utilizing ultra-fine grained materials (Pd, 6nm grain size; Mg, 12 nm grain size; CaF2, 7 nm grain size) about 30 to 50 vol% of which consist of grain boundaries. The results obtained suggest that (1) The interatomic potentials in grain boundaries in metals differ from the lattice ...

Grain-boundary relaxation in nanocrystalline Fe was studied by high-resolution transmission electron microscopy HREM , and its effect on plasticity was characterized by nanoindentation. Samples with grain size of 9.8 nm were synthesized by mechanical attrition and subsequently annealed at low temperatures 80 and 100 °C without affecting the grain size. While the hardness is not significantly af...