Bulk multimodal-grained irons with large plasticity fabricated by spark plasma sintering

We report on the formation of a new bulk multimodal-grained (MGed) iron with a large true strain of 58% and high strength of 955 MPa by spark plasma sintering. The new MGed structure contains fine-grained α-Fe matrix and ultrafine-grained equiaxed and acicular α-Fe enhancing phases. The large plastic strain can be attributed to the increased dislocation motion and improved shear deformation ability resulted from such MGed structure containing three different α-Fe morphologies.