Abstract
A consolidation process of the nanocrystalline iron powder has been investigated to produce a high strength bulk plate of superfine grained (SFG) pure iron. The nanocrystalline iron powder was prepared by mechanical milling (MM) of a high purity carbonyl iron powder in argon or hydrogen atmosphere. The consolidation was done at a pressure of 300 MPa using a spark plasma sintering (SPS) machine. The SFG iron which was sintered at 570°C for 600 s using the powder milled in hydrogen has a relative density of 98.5 %, a grain size of 102 nm and a fracture strength of 1370 MPa. The fracture strength is strongly sensitive to the relative density and the oxygen content.
