Preparation of Ti-aluminide reinforced in situ aluminium matrix composites by reactive hot pressing

Aluminium based metal matrix composites reinforced with in situ Ti-aluminide and alumina particles were prepared by reactive hot pressing a powder mix of aluminium and nanosized TiO2 powders. The reinforcements were formed in situ by exothermal reaction between the TiO2 nano crystalline powder and aluminium. The thermal characteristics of the in situ reaction were studied with the aid of Differential scanning calorimetry (DSC). X-ray diffraction (XRD), Energy dispersive spectroscopy (EDS) and Scanning electron microscopy (SEM) techniques were employed to study the microstructural architecture of the composites as a function of hot pressing temperature and volume percent reinforcement. Microhardness measurements on the as prepared in situ aluminium matrix composites exhibit significant increase in hardness with increase in hot pressing temperature and volume fraction of reinforcement.