Correlation of high temperature oxidation with tensile properties for Ti–48Al–2Cr–2Nb and Ti–48Al–2Cr–2Fe alloys

Effect of niobium on the structure and high-temperature oxidation of TiAl–Ti5Si3 eutectic alloy

“…DT 2 ¼ g=ðtE ox ð1 À nÞÞ; (1) where g is the fracture energy per unit area of oxide/metal interface, t is the oxide thickness, Da is the difference in CTE's of metal and oxide, E ox and n are the Young's modulus and Poisson's ratio, respectively [6]. By assuming for a simplicity that g, Da, E ox and n do not depend on Nb amount in rutile, the square of critical temperature change is inversely proportional to the scale thickness.…”

“…Therefore, besides Ti and Al, commercial g-TiAl intermetallics also contain other additives, such as Nb, Cr, V, Si etc., improving oxidation resistance and ductility. A lot of works have been reported on the hightemperature oxidation of Nb-containing Ti-Al intermetallics [1][2][3][4][5][6]. These investigations revealed that the scales have a layered structure, consisting of rutile, alumina, rutile þ alumina and nitride sub-layers.…”

Centrifugal precision cast TiAl turbocharger wheel using ceramic mold

“…However, in spite of above good properties of them, the low temperature elongation and harsh environment (subjected to long-term exposure to high temperature exhaust gases) limits the development in vehicle and aerospace industries. Alloying additions to TiAl-based alloy much contributed to overcome the obstacle, which once stood in their way for the practical application (Li and Taniguchi, 2005). Recently, a second-generation gamma titanium aluminide (Ti-47Al-2Cr-2Nb alloy (TACN, at.%)) was evaluated as a remarkable interesting material in turbocharger fabrication (Liu and Wang, 2006).…”

Tensile properties and high temperature creep behavior of microalloyed Ti–Ti3Al–Nb alloys by directional solidification

“…Furthermore, almost no reports have been available up to date with respect to the high temperature creep deformation in the ternary Ti-Al-Nb alloys with a moderate Al concentration (10-20 at.%), where some of the remaining Ti is employed as the tough phase to enhance the ductility of Ti-Al-Nb alloys resulting in a composite microstructure of Ti-Ti 3 Al-Nb. On the other hand, it has been indicated that the addition of Cr is mostly effective in enhancing the ductility whereas the Mo addition promotes the ␤ solidification process and simultaneously provides some solid solution strengthening in TiAl alloys with Al content ranging from 42 to 49 at.% [1,[33][34][35].…”