Vacancies and vacancy clusters in shockhyphen;loaded molybdenum: Direct observations by transmission electron and fieldhyphen;ion microscopy

摘要

A novel experimental sandwich arrangement of molybdenum thin sheets and wires was shockhyphen;loaded at a pressure of 150 kbar (for 2 mgr;sec), and thin foils and emission end forms prepared from these samples were simultaneously examined by transmission electron and fieldhyphen;ion microscopy, respectively. Dislocation loop densitis were observed to be 5times;109cmminus;3in the annealed foil samples as compared with 4times;1014cmminus;3in the shockhyphen;loaded foil samples, and 75percnt; of the loop types analyzed were vacancy. The direct measurement of vacancy density in the fieldhyphen;ion microscope revealed twice as many vacancies (including aggregates) in the shockhyphen;loaded wires as compared with the annealed unshocked wires.