In situ study on enhanced heavy ion irradiation tolerance of porous Mg

Mg is known to be highly vulnerable to irradiation damage. Here we show, via in situ Kr ion irradiation studies inside a transmission electron microscope, that both defect density and size have been reduced substantially in porous Mg compared to dense coarse-grained Mg counterpart. Both prism and basal dislocation loops form at low dose in coarse-grained Mg, but basal loops dominate at a higher dose level. Meanwhile, in irradiated porous Mg, basal loops prevail throughout the entire irradiation process. Mechanisms that lead to enhanced irradiation tolerance of porous Mg are discussed.