TENSILE BEHAVIOR OF THE L12 COMPOUND AL67TI25CR8

Temperature-related variations in tensile yield strength and ductility were studied on cast, homogenized and isothermally forged Al67Ti25Cr8. Yield strength dropped discontinuously between 623 K and 773 K and then decreased gradually with increasing temperature. Below 623 K, fracture occurred prior to macroscopic yielding. Ductility decreased from 0.2% at 623 K to zero at 773 K, but increased again at higher temperatures. At 1073 K, an elongation of approximately 19% was obtainable, and ultimate tensile strength and localized necking were observed. Fracture surfaces and deformed microstructures were examined. The 1073 K tensile specimen that exhibited approximately 19% elongation showed grain boundary serrations and some evidence of recrystallization (likely dynamic) although fracture occurred predominantly via an intergranular mode.