Preparation of Fe-aluminide reinforced in situ metal matrix composites by reactive hot pressing

In situ Fe-aluminide and alumina reinforced aluminium matrix composite was prepared by hot pressing a powder mix of aluminium and Fe2O3 powders containing nanosized crystallites. The reinforcements were formed in situ by exothermal reaction between the Fe2O3 nanoparticles and the host aluminium matrix. The thermal characteristics of the in situ reaction were studied with the aid of differential scanning calorimetry (DSC). Scanning electron microscopy (SEM) along with the energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) techniques were employed to study the microstructural architecture of the composites as a function of hot pressing temperature and volume percent reinforcement. Micro-hardness measurements on the as-prepared in situ aluminium matrix composites show significant increase in hardness with increase in hot pressing temperature and volume fraction of reinforcement.