Application of modern creep lifing techniques to a gamma-TiAl alloy (Ti- 45Al-2Mn-2Nb)

Abdallah, Z; Whittaker, M T; Bache, M R; Dixon, M

Abstract

Intermetallic materials such as gamma titanium alumindes (-TiAl) offer an extremely attractive balance of properties. In support of potential engineering applications it is essential that the material properties are well understood across a wide temperature range. For applications where static loading will predominate at relatively high temperature, creep deformation would be expected to be significant. In addition to fundamental creep characterisation, it is critical that accurate models can be devised not only to interpolate and extrapolate creep performance but also to determine stress relaxation, thereby also enabling accurate fatigue life prediction. The current paper will employ the -TiAl alloy Ti-45Al-2Mn-2Nb as a model system and seeks to evaluate the performance of two modern creep lifing techniques, the Wilshire Equations and hyperbolic tangent methods, in comparison to the more traditional Larson-Miller approach. The paper specifically focuses on the reliability of extrapolation methods using the different approaches, along with the correlation to the observed microscale deformation phenomena. The paper also seeks to relate the fracture mechanisms observed within the alloy to the macroscopic creep behaviour and comments on the possibility of extended use of these alloys when compared to more traditional materials.

• Presentation Conference Type: Conference Paper (unpublished)
• Conference Name: The 9th International Conference on Creep and Fatigue at Elevated Temperatures
• Start Date: Sep 25, 2012
• End Date: Sep 27, 2012
• Deposit Date: Jul 12, 2023
• Keywords: Creep life; titanium aluminides (-TiAl); oxidation; ductility
• Public URL: https://uwe-repository.worktribe.com/output/10932361