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The Influence of Thermal History and Alloying Elements on Temporary Strengthening of Thin Al-Cu Films

Published online by Cambridge University Press:  10 February 2011

J. P. Lokker
Affiliation:
[email protected] Nano Physics and Technology, Delft University of Technology, P.O. Box 5046 2600 GA Delft, The Netherlands
G. C. A. M. Janssen
Affiliation:
[email protected] Nano Physics and Technology, Delft University of Technology, P.O. Box 5046 2600 GA Delft, The Netherlands
S. Radelaar
Affiliation:
[email protected] Nano Physics and Technology, Delft University of Technology, P.O. Box 5046 2600 GA Delft, The Netherlands
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Abstract

The influence of Cu on the response of Al-Cu thin films to thermally induced stress is studied. The copper concentration is varied between 0 and 1.15 at. %. It is proposed that copper atoms which have not formed precipitates, largely affect the mechanical behaviour. This idea is supported by the following observations. An isothermal hold results in temporary strengthening of the films. The extent of this strengthening increases with copper concentration, increases with decreasing isothermal hold temperature and saturates with increasing isothermal hold period. Based on these observations the large tensile stress increase below 200 °C is ascribed to the formation of Cottrell atmospheres.

Type
Research Article
Copyright
Copyright © Materials Research Society 2000

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