Open Access
Article Number 06003
Number of page(s) 8
Section Applied Research and Applications: Testing and Modelling
Published online 01 September 2009
ESOMAT 2009, 06003 (2009)
DOI: 10.1051/esomat/200906003

Investigations of Solid Phase Processes in CuAlNi Base Shape Memory Alloys

Márton Benke1, V. Mertinger2 and L. Daróczi3

1  Fellow researcher, Dept. of Metallurgy and Metalforming, University of Miskolc,H- 3515, MiskolcEgyetemvaros, Hungary
2  PhD Associate Professor, Dept. of Physical Metallurgy and Metalforming, University of Miskolc, H-3515, Miskolc-Egyetemvaros, Hungary
3  Assistant Professsor, Dept. Of Solid State Physics, University of Debrecen, H-4010, Bem Square 18/, Debrecen, Hungary

Published online: 1 September 2009

Cu based Shape Memory Alloys are favored because of their high transformation temperatures and low price. However, their brittle behavior and the ageing processes due to cycle heating limit the alloys’ practicability. To extend their suitability, Mn and Fe were added to the base CuAlNi alloy in order to increase ductility. The ageing processes and the effect of the Mn and Fe addition were examined using differential scanning calorimetry, optical microscopy, scanning electron microscopy, transmission electron microscopy and in-situ optical microscopy. Transformation temperatures shifted to higher temperatures in the CuAlNi alloy as the ageing time was increased. In CuAlNiMn and CuAlNiMnFe alloys the thermoelastic martensitic transformation disappeared in the aged samples. The cause of this effect turned out to be an exothermic process starting at around 300°C, which was previously not known. The examinations were focused to characterize and identify this exothermic process.

© Owned by the authors, published by EDP Sciences 2009