A micromechanics-based model for shear-coupled grain boundary migration in bicrystals

Shear-coupled grain boundary migration assisted by unusual atomic shuffling

Shear-coupled grain boundary (GB) migration can be an efficacious mechanism to accommodate plastic deformation when the grain size of polycrystalline materials goes small. Nevertheless, how this kind of GB motion comes into play at the atomic level has not been fully revealed. Here, we have investigated the shear-coupled migration (SCM) of typical [100] group symmetrical tilt GBs in bcc W using...

Imaging grain boundary grooves in hard-sphere colloidal bicrystals.

Colloidal particles were sedimented onto patterned glass slides to grow three-dimensional bicrystals with a controlled structure. Three types of symmetric tilt grain boundaries between close-packed face-centered-cubic crystals were produced: Σ5(100),Σ17(100), and Σ3(110). The structure of the crystals and their defects were visualized by confocal microscopy, and characterized by simple geometri...

Phenomenology and Mechanism of Grain Boundary Sliding in Zinc Bicrystals

CHARGED GRAIN-BOUNDARIES IN n-Ge BICRYSTALS

Germanium bicrystals with two types of low-energy symmetric tilt boundaries, Z 9 and Z 1 1 (CSL model classification) were grown. Current-voltage characteristics of grainboundaries were measured in the temperature range 77 K-420 K. Potential barriers were found only at Z 1 1 boundaries in n Ge which confirms the theoretical predictions of the atomic structure of these boundaries [I]. From the e...

Effect of Grain Boundary Melting on Sliding in Bicrystals: a Molecular Dynamics Study

Grain boundaries arc known to exert a profound influence on the properties of polycrystalline materials at high temperature. Experimental studies on grain boundary sliding in Al bicrystals (I), or more recently in Zn bicrystals (2), show a change in the temperature dependence of the sliding rate at temperatures between 70% to 90% of the bulk melting point. The critical temperature at which a ch...