English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Creep strength of centrifugally cast Al-rich TiAl alloys

MPS-Authors
/persons/resource/persons135043

Kelm,  K.
Center for Materials Analysis, Technische Fakultät, Christian-Albrechts-Universität Kiel, Kaiserstraße 2, D-24143 Kiel, Germany ;
Electron Microscopy and Analytics, Center of Advanced European Studies and Research (caesar), Max Planck Society;

/persons/resource/persons182739

Irsen,  S.
Electron Microscopy and Analytics, Center of Advanced European Studies and Research (caesar), Max Planck Society;

Locator
There are no locators available
Fulltext (public)
There are no public fulltexts available
Supplementary Material (public)
There is no public supplementary material available
Citation

Sturm, D., Heilmaier, M., Saage, H., Paninski, M., Schmitz, G. J., Drevermann, A., et al. (2009). Creep strength of centrifugally cast Al-rich TiAl alloys. Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 510-11, 373-376.


Cite as: http://hdl.handle.net/11858/00-001M-0000-0028-60FA-D
Abstract
High-temperature creep of a binary Al60Ti40 (at.%) alloy in the as-cast state and after annealing at 1223 K for 200 h which produced nearly lamellar gamma-TiAl + r-Al2Ti microstructure was studied utilizing creep compression tests in a temperature range between 1173 and 1323 K in air. The material was manufactured by centrifugal casting. Microstructural characterization was carried out employing light-optical scanning (SEM) and transmission electron microscopy (TEM) as well as X-ray diffraction (XRD) analyses. It is shown that the alloy exhibits reasonable creep resistance at 1173 K, especially in relation to its low density of around 3.8 g/cm(3). Stress exponents calculated as n = Delta log (strain rate)/Delta log (stress) = 4 were found to be relatively constant for the temperature and stress regime investigated. This indicates that dislocation climb may be the rate controlling creep mechanism. The assessment of creep tests conducted at identical stress levels and varying temperatures yielded activation energies for creep of around Q = 457 kJ/mol in the as-cast condition. This value is significantly higher than those found in literature for interdiffusion of Al or Ti in gamma-TiAl. It is concluded that the difference is a due to the instability of the microstructure of the as-cast multi-phase alloy. (C) 2009 Published by Elsevier B.V