Abstract
Pure iron powders were mechanically milled for 6kmin (100h) to produce nanocrystals with the grain diameter of 13 nm that was measured by X-ray diffraction. The nano-structured iron powders were sintered at temperatures between 556 to 807 °C under an applied pressure of 50 to 79 MPa to form a disc having a diameter of 50 mm. The mean grain size of the compacted discs characterized by transmission electron microscope grows from 90 to 310 nm with increasing sintering temperature. A maximum Vickers hardness and a maximum fracture stress obtained in the present study were 356 Hv and 630 MPa, respectively. The results are discussed in conjunction with the result of warm pressing study performed by Malow and Koch.
