Study on preparation and mechanical properties of Fe3Al–20wt.%Al2O3 composites

Abstract: Fe3Al–20wt.%Al2O3 ultrafine grained composites were prepared by mechanical alloying (MA) with subsequent plasma activated sintering (PAS). Microstructures of the Fe3Al–20wt.%Al2O3 composites and Fe3Al alloys were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrum (EDS) and transmission electron microscope (TEM). Then the relative density, room temperature hardness and compression property at 25–800°C of the sintered samples were tested and analyzed. The results showed that Fe3Al–20wt.%Al2O3 composites sintered at 1100°C had fine grain size, high relative density, high hardness and excellent microstructure. The sharp drop in strength of Fe3Al alloys above 600°C was improved via introducing 20wt.%Al2O3 although the plastic toughness and strength at 25–400°C of the composites was lower than Fe3Al. [Copyright &y& Elsevier]