Intragranular deformation mechanisms during ambient-temperature creep in hexagonal close-packed metals

Intragranular deformation mechanisms were investigated for ambient-temperature creep of pure hexagonal close-packed (h.c.p.) metals, i.e. commercially pure titanium, pure magnesium and pure zinc, by transmission electron microscopy and electron back-scatter diffraction pattern mapping analysis. First, straightly aligned dislocation arrays were observed in all of the specimens. Second, although the Burgers vectors of (a) and several slip systems were observed, only one slip system was activated inside of each grain. Third, the deformation twins that form during creep hinder creep strain. Therefore, the dominant intragranular deformation mechanism of ambient-temperature creep is a planner slip of dislocations inside of a grain