Supertransus processing of TiAl-Based alloys

Fine-grained lamellar microstructures would be expected to exhibit high strength, creep resistance, fracture toughness, and moderate ductility. High-temperature extrusion was used to produce fine-grained lamellar microstructures in both ingot metallurgy (I/M) and powder metallurgy (P/M) Ti-48Al-2Nb-2Cr alloys. The effect of processing parameters, such as extrusion temperature and cooling rate, on the microstructure and properties was determined. In addition, the thermal stability of the microstructure was evaluated by subsequent heat treatments. Although fine-grained lamellar microstructures were generated in both ingot and powder metallurgy materials, processing had a significant effect on the microstructure and properties of the resultant materials.