Characterization of TiAl intermetallic rods produced from elemental powders by hot extrusion reaction synthesis (HERS)

Rods of a mixture of two intermetallic phases, TiAl (gamma) and Ti3Al(alpha(2)), have been produced directly from elemental powders of Ti-46.2 at% Al composition using a new hot extrusion reaction synthesis process (HERS) at a low initial temperature and over a short process time. The microstructures of the HERS rod were characterized by X-ray diffraction (XRD), optical microscopy, scanning electronic microscopy (SEM), transmission electronic microscopy (TEM) and energy dispersive spectroscopy (EDS). The microhardness of each phase was also measured. The dominant mechanisms during synthesis were analysed by combining these observations with the results obtained using differential scanning calorimeter (DSC).