Materials Science. Non-Equilibrium Phase Transformations.
Vol. 9 (2023), Issue 2, pg(s) 35-37

Physical vapor deposited coatings with shape memory effect

  • 1 Fraunhofer IWS, Dortmund, Germany
  • 2 Institute of Materials Science; TUD Dresden University of Technology, Dresden; Germany

Abstract

Shape memory effects have been observed not only in bulk materials but also in PVD thin films. We have deposited copper-base shape memory alloys (SMAs) on Al substrates using DC sputtering. The coatings exhibit diffusionless transformation from the hightemperature austenite phase to the low-temperature martensite phase. This can be both, thermally controlled as a kind of two-way memory effect and stress-induced, giving a pseudoelastic behavior. The structures and microstructures of the coatings were analyzed by X-ray diffraction and optical microscopy. The martensitic transformation temperature was determined by dilatometric measurement. The coatings exhibit a martensite start temperature (Ms) very close to that of bulk materials. The SMA thin films have the ability to recover from large transformation stresses and strains when heated. In addition, their pseudoelasticity makes them potentially suitable as a protective layer against cavitation erosion.

Keywords

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