Microstructure and mechanical properties of Fe 3Al alloys prepared by MA-PAS and MA-HP

Fe3Al alloys with nearly full density were fabricated by plasma activated sintering (PAS) and hot pressing (HP) from mechanical alloyed Fe-28%Al (mole fraction) powders, respectively. It is found that A2-type Fe3Al alloys were obtained by PAS, and they had a heterogeneous grain size distribution, most areas had a grain size smaller than 500 nm, and other areas had a grain size of about 1 μm. Different to PAS, D03-type Fe3Al alloys with a grain size of of 1-2 μm were obtained by HP. The compression testing results show that yield strength values of Fe3Al alloys fabricated by PAS and HP are almost equal at an elevated temperature, and the compression yield strength was about 100 MPa for all at 800 °C. The room temperature compression ductility of Fe3Al alloys by PAS was about 20%, which was superior to that of Fe3Al alloys prepared by HP and casting.