DEFORMATION BEHAVIOR OF ULTRAFINE-GRAINED IRON PROCESSED BY EQUAL-CHANNEL-ANGULAR PRESSING

摘要

In the present study, the microstructural evolution during pressing and the deformation behavior of ultrafine-grained pure Fe processed via equal-channel angular pressing (ECAP) was investigated by means of transmission electron microscopy, tensile and compressive mechanical testing. Intensive dislocation-cell blocks, as well as ultrafine grains, were observed after severe plastic deformation. Because of the presence of ultrafine-grained microstructure and non-equilibrium grain boundaries, the materials display a distinct mechanical behavior as compared to that of their counterpart unprocessed materials. Several mechanical behavior issues including high strength, necking deformation and low ductility are addressed in the present paper.