Experimental method for true in situ measurements of shear-coupled grain boundary migration

A novel set-up developed to continuously observe and measure stress-driven grain boundary migration is presented. A commercial tensile/compression scanning electron microscope hot stage was utilized for in situ observations of mechanically loaded samples at elevated temperatures up to 850 oC by recording orientation contrast images of bicrystal surfaces. Two sample holders were designed and fabricated for applying a shear stress to the boundary in bicrystals of various geometries. The results of the first measurements in Al bicrystals are presented.