The structure and mechanical properties of Fe3Al–30 vol.% Al2O3 nanocomposite

Fe3Al–30 vol.% Al2O3 nanocomposite powder was fabricated via two routes. The first route involved the ball milling of Fe2O3–Al–Fe powder mixtures to produce in situ Al2O3 nanoparticles in Fe3Al matrix via mechanochemical reaction of Fe2O3 and Al. In the second route, Fe3Al–Al2O3 nanocomposite was prepared by ex situ addition of Al2O3 nanopowder to Fe–Al powder mixture followed by ball milling. The prepared powders were subsequently consolidated using cold pressing and sintering. The phase analysis, morphology and microstructure of samples were studied by X-ray diffractometry and scanning electron microscopy. Mechanical properties of consolidated powders were determined using hardness test and flexural strength measurements using three-point flexure test at room temperature. The results showed that the Fe3Al–Al2O3 produced via the first route had a significantly improved microstructure and mechanical characteristics in comparison with material obtained via the second route as well as some other techniques.