Influence of symmetrical 〈101¯0〉 high-angle tilt grain boundaries on the local mechanical properties of magnesium bicrystals

Nanoindentation was used to study the local mechanical properties in the vicinity of 〈101¯0〉 tilt grain boundaries with different misorientation angle in magnesium bicrystals. Load and width of the first pop-in close to and at the grain boundaries were significantly lower than in the grain interior. The load displacement curves obtained close to the boundaries also showed an additional second pop-in event, which was interpreted as characteristic for the propagation of dislocations through the grain boundary. Critical shear-stress for the second pop-in was found to differ substantially for grain boundaries with different structure.