ESOMAT 2009, 05008 (2009)
DOI: 10.1051/esomat/200905008

Martensitic transformation in NiTiCo strip covered by nanocrystalline platinum layer

T. Goryczka¹, J. Lelatko¹, D. Vokoun² and P. Ochin<sup>3

1</sup>  University of Silesia, Institute of Materials Science, Bankowa 12, 40-007 Katowice, Poland
²  Institute of Physics ASCR, v.v.i., Na Slovance 2, 18221Prague, Czech Republic.
³  ICMPE CNRS- Universite Paris 12 (UMR 7182) 2-8 rue Henri Dunant 94320 Thiais, France

tomasz.goryczka@us.edu.pl

Published online: 1 September 2009

Abstract
The surface modifications and their effects on the transformation characteristics of shape memory alloys are of interest. The NiTiCo strip was produced applying twin roll casting technique and after that covered by platinum layer using magnetron sputtering. Structure of the layer was studied by means of X-ray diffraction and electron microscopy. Transformation temperatures were determined using differential scanning calorimeter (DSC). The investigations show that in the NiTiCo strip occurs two-steps (by the R-phase) reversible martensitic transformation between the parent B2 phase and the monoclinic martensite B19’. The platinum layer reveals nanocrystalline structure with average grain diameter of 41 nm. It was stated that the nanocrystalline platinum layer does not limit martensitic transformation in the covered strip and can be used as a protective layer.

© Owned by the authors, published by EDP Sciences 2009