Fabrication of TiAl Alloy Powders by High-Energy Ball Milling and Low Temperature Sintering

Ti/Al(Ti-50at.%Al) composite powders were prepared by high-energy ball milling followed by reaction sintering heat treatment at 550°C ~ 650°C for 2 hours. Mechanical alloying of TiAl had been performed in a high energy plant ball after different milling times and pre-sintered at different temperatures. The particle sizes of Ti/Al powders were analyzed by scanning electron microscopy (SEM). X-ray diffraction (XRD) analysis was performed for microstructural characterization. The results show that microstructural and morphological changes of high energy milled powder are studied as a function of milling time. Over 600°C TiAl powders are completely alloyed by being sintered at different temperatures. The powders are mainly composed of γ-TiAl as well as a small amount of AlTi3. The TiAl alloy powders of high energy ball mill/2h and sintered at 650°C/2h get plasma spheroidization. Spheroidizing powders with fine texture, γ-TiAl and AlTi₃ phase, particle size of 10~40μm are obtained.