Characteristic features and thermal stability of molybdenum processed by different ways of severe plastic deformation

Characteristic features and thermal stability of the structure of molybdenum processed by high pressure torsion, equal-channel angular pressing or multy-step forging have been investigated using transmission electron microscopy, X-ray diffraction analysis and orientation imaging microscopy. The structural factors responsible for the strengthening and thermal stability of molybdenum processed have been obtained. It has been demonstrated that only high pressure torsion is an effective method to refine molybdenum structure (down to 0.2 mu m). Recrystallization occurs during the others investigated processing disabling significant grain size reduction.