Creep deformation mechanisms in a γ titanium aluminide

Research output: Contribution to journalArticle

Authors

  • Z. Abdallah
  • Rengen Ding
  • Nigel Martin
  • Mark Duxib
  • Martin Bache

Colleges, School and Institutes

Abstract

Titanium aluminides (TiAl) are considered as potential alternatives to replace nickel-based alloys of greater density for selected components within future gas turbine aero-engines. This is attributed to the high specific strength as well as the good oxidation resistance at elevated temperatures. The gamma (γ) titanium aluminide system Ti-45Al-2Mn-2Nb has previously demonstrated promising performance in terms of its physical and mechanical properties. The main aim of the current study, which is a continuation of a previously published paper, aims at evaluating the performance of this titanium aluminide system under high temperature creep conditions. Of particular interest, the paper is strongly demonstrating the precise capability of the Wilshire Equations technique in predicting the long-term creep behaviour of this alloy. Moreover, it presents a physically meaningful understanding of the various creep mechanisms expected under various testing conditions. To achieve this, two creep specimens, tested under distinctly different stress levels at 700 °C have been extensively examined. Detailed microstructural investigations and supporting transmission electron microscopy (TEM) have explored the differences in creep mechanisms active under the two stress regimes, with the deformation mechanisms correlated to Wilshire creep life prediction curves.

Details

Original languageEnglish
Pages (from-to)616-623
JournalMaterials Science and Engineering A
Volume673
Early online date27 Jul 2016
Publication statusPublished - 15 Sep 2016

Keywords

  • Titanium aluminides, Intermetallics, Creep, Wilshire equations, TEM