Creep deformation mechanisms in a γ titanium aluminide

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:673

Article

Abdallah, Z.¹  Ding, Rengen²  Martin, Nigel³  Dixon, Mark³  Bache, Martin¹ 

[1] Swansea Univ, Coll Engn, Inst Struct Mat, Bay Campus, Swansea SA1 8EN, W Glam, Wales

[2] Univ Birmingham, Interdisciplinary Res Ctr Mat, Birmingham B15 2TT, W Midlands, England

[3] Rolls Royce Plc, POB 31, Derby DE24 8BJ, England

关键词: Titanium aluminides;    Intermetallics;    Creep;    Wilshire equations;    TEM;   

DOI  :  10.1016/j.msea.2016.07.109

来源: Elsevier

【 摘 要 】

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 (gamma) 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 degrees C have been extensively examined. Detailed micro structural 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. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

Free