Loading...

Sputter alloying of Ni, Ti and Hf for fabrication of high temperature shape memory thin films

Sanjabi, S ; Sharif University of Technology | 2007

397 Viewed
  1. Type of Document: Article
  2. DOI: 10.1179/026708306X81469
  3. Publisher: 2007
  4. Abstract:
  5. In the present paper, the fabrication and characterisation of typical high temperature Ni(Ti+ Hf) alloyed thin films produced by simultaneous sputter deposition from separate elemental Ni, Ti and Hf targets are presented. Film composition, determined by energy dispersive X-ray spectroscopy, was controlled by adjusting the ratio of powers applied to each target. Films deposited at room temperature had an amorphous structure and subsequent annealing at 550°C was carried out in a high vacuum environment, based on crystallisation temperature evaluation by differential scanning calorimetry (DSC). High temperature martensitic transformation, confirmed by DSC and variable temperature X-ray diffraction (XRD), was achieved by deposition of (Ti+ Hf) rich Ni-Ti-Hf films. Any slight change of composition towards Ni rich reduced the transformation temperature. Atomic force microscopy and XRD illustrated that the films had a fine grain structure (∼100 nm). One way shape memory effect was observed at ∼200°C in a film with composition of 15.6 at.-%Hf. © 2007 Institute of Materials, Minerals and Mining
  6. Keywords:
  7. Annealing ; Crystallization kinetics ; Differential scanning calorimetry ; Energy dispersive X ray analysis ; Magnetron sputtering ; Shape memory effect ; Film composition ; High temperature shape memory ; Transformation temperature ; Thin films
  8. Source: Materials Science and Technology ; Volume 23, Issue 8 , 2007 , Pages 987-991 ; 02670836 (ISSN)
  9. URL: https://www.tandfonline.com/doi/abs/10.1179/026708306X81469