In Situ High-Energy X-ray Diffraction during Hot-Forming of a Multiphase TiAl Alloy

Metals

Andreas Stark²  Marcus Rackel²  Aristide Tchouaha Tankoua¹  Michael Oehring²  Norbert Schell²  Lars Lottermoser²  Andreas Schreyer²  Florian Pyczak² 

[1] Institute of Materials Physics and Technology, Hamburg University of Technology, Hamburg 21073, Germany; E-Mail:;Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Geesthacht 21502, Germany; E-Mails:

关键词: crystallographic texture;    X-ray diffraction;    synchrotron radiation;    intermetallic alloy;    titanium aluminides based on γ-TiAl;    hot-forming;    thermo-mechanical processing;    phase constitution;   

DOI  :  10.3390/met5042252

来源: mdpi

【 摘 要 】

Intermetallic γ-TiAl based alloys exhibit excellent high-temperature strength combined with low density. This makes them ideal candidates for replacing the twice as dense Ni base super-alloys, currently used in the medium temperature range (~700 °C) of industrial and aviation gas turbines. An important step towards the serial production of TiAl parts is the development of suitable hot-forming processes. Thermo-mechanical treatments often result in mechanical anisotropy due to the formation of crystallographic textures. However, with conventional texture analysis techniques, their formation can only be studied after processing. In this study, in situ high-energy X-ray diffraction measurements with synchrotron radiation were performed during hot-forming. Thus, it was possible to record the evolution of the phase constitution as well as the formation of crystallographic texture of different phases directly during processing. Several process temperatures (1100 °C to 1300 °C) and deformation rates were investigated. Based on these experiments, a process window can be recommended which results in the formation of an optimal reduced texture.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.