The dynamics of dislocation-free crystal facets is examined in the context of grain boundary grooves at the junction between two crystallites of a solid and the liquid phase. The geometry and thermal conditions of grain boundary grooves allow a detailed analysis of facet morphology during solidification in terms of the nucleation and spreading rates of elementary crystal planes. Observations on...

A systematic study of crack tip interaction with grain boundaries is critical for improvement of multiscale modeling of microstructurally-sensitive fatigue crack propagation and for the computationally-assisted design of more durable materials. In this study, single, biand large-grain multi-crystal specimens of an aluminum-copper alloy are fabricated, characterized using electron backscattered ...

Using simulations we explore the behaviour of two-dimensional colloidal (poly)crystals doped with active particles. We show that these active dopants can provide an elegant new route to removing grain boundaries in polycrystals. Specifically, we show that active dopants both generate and are attracted to defects, such as vacancies and interstitials, which leads to clustering of dopants at grain...

Monolithic integration of III-V optoelectronic devices with materials for various functionalities inexpensively is always desirable. Polysilicon (poly-Si) is an ideal platform because it is dopable and semiconducting, and can be deposited and patterned easily on a wide range of low cost substrates. However, the lack of crystalline coherency in poly-Si poses an immense challenge for high-quality...

κ-carbide in lightweight steel is studied. Its thermal stability, crystal morphology, orientation relationship, degree of lattice misfit and mechanical properties are measured experimentally. The mechanisms for the microstructural evolution of κ-carbide are considered based on the crystal structure, lattice misfit, element diffusivity, and solute partition. The hard γ/κ grain and ductile α+κ gr...

κ-carbide in lightweight steel is studied. Its thermal stability, crystal morphology, orientation relationship, degree of lattice misfit and mechanical properties are measured experimentally. The mechanisms for the microstructural evolution of κ-carbide are considered based on the crystal structure, lattice misfit, element diffusivity, and solute partition. The hard γ/κ grain and ductile α+κ gr...

When three grain boundaries having misorientations generating coincidence site lattices (CSLs) meet at a triple junction, a common (triple-junction) CSL is formed. A theory is developed as a set of theorems establishing the relationships between the geometrical parameters of the grain-boundary and triple-junction CSLs. Application of the theory is demonstrated in detail for the case of the cubi...

Introduction: Ice grain size controls the geodynamic evolution of the ice I shells of large to mid-sized icy satellites. Grain size controls the viscosity of ice [1,2], and thus, the heat flux from the outer ice I shell by controlling the likelihood and efficiency of convection. In addition, the rheology of ice controls the depth to the brittle/ductile transition, which is a key control on endo...