“…TiAl-based alloy is about 4 g/cm 3 which is about half of that of commonly used Ni-based superalloys, and therefore has attracted broad attention as potential candidates for high-temperature structural application in the fields of turbocharger manufacture (Jovanovic et al, 2005;Tetsui and Ono, 1999;Nakagawa et al, 1992). Due to low density (3.8 g/cm 3 ), high specific strength, high Young's modulus and excellent oxidation resistance at high temperatures, they represent a good alternative for nickel-based superalloys (Zollinger et al, 2007;Qu and Wang, 2007;Cao et al, 2007). Moreover, TiAl-based alloys consist of the major ␥-phase and minor ␣ 2 -phase, are nearly equal to Ni-based superalloys for turbine blades in specific tensile strength and specific creep strength but slightly inferior to superalloys in oxidation resistance above 700 • C (Jovanovic et al, 2005; Yamaguchi et al, 2000).…”