The increasing demands on high-temperature materials in terms of strength, creep and oxidation resistance requires the development of novel Titanium aluminide alloys. The currently applied γ-TiAl alloys with an Al-content in the range of 43-48 at.% exhibit a maximum operation temperature of 800 °C due to their limited oxidation and creep resistance. Therefore, this study analyses the potential of TiAl alloys in the Al-rich side of the phase diagram (> 50 at.%). The aim was a basic characterization of powder metallurgical produced materials. For this purpose, three alloys with a variable aluminium content and additional alloying elements such as Mo, Nb, W, C, and Y were investigated. Of particular interest is the influence of alloying elements on the phase diagram, as well as on phase transformation and precipitation behavior. The influence on the microstructure and the properties regarding a possible industrial application were determined in a first "screening". The powder, which was produced via gas-atomization, as well as hot-isostatic pressed material were analyzed by means of light and scanning electron microscope. X-ray diffraction investigation with subsequent Rietveld analysis was conducted to determine the phase fractions. Phases, which could not be contified by X-ray diffraction measurements, e.g. due to their low volume fractions, were examined by energy dispersive X-ray analysis. Hardness measurements were used to estimate the influence in mechanical properties. Additionally, differential scanning calorimetry measurements were carried out to determine the effects of alloying elements on the phase transformation behaviour and to define specifical heat-treatment parameters. Finally, the heat treated microstructure were also investigated by the analytical methods described above.