ULTRAHIGH-PLASTICITY DOUBLE-SIZE-DISTRIBUTION SUPERFINE CRYSTAL/MICROMETER CRYSTAL BLOCK IRON MATERIAL AND PREPARATION METHOD THEREFOR

摘要

An ultrahigh-plasticity double-size-distribution superfine crystal/micrometer crystal block iron material. A microstructure of the material uses a blocky micrometer crystal α-Fe as a matrix phase, and uses equiaxial α-Fe and needle-shaped α-Fe of a superfine crystal as reinforced phases, and the material has excellent comprehensive mechanical property and very high plastic deformation capacity, and has a good application prospect. A method for preparing the ultrahigh-plasticity double-size-distribution superfine crystal/micrometer crystal block iron material comprises: grinding high-purity iron powder into nanocrystal powder first by using high-energy ball, and then performing fast sintering by using a spark plasma sintering system, a sintering temperature Ts being greater than or equal to 1253K and less than or equal to 1335K, a sintering time is 14-26min, and a sintering pressure is 40-500MPa. The preparation method is simple, and convenient to operate; a crystal particle size is controllable; a yield is high; a raw material is saved; and the material is close to the final forming.