Acta Metallurgica Sinica (English Letters) ›› 2015, Vol. 28 ›› Issue (10): 1230-1237.DOI: 10.1007/s40195-015-0317-6

• Orginal Article • Previous Articles     Next Articles

Transformation of the TiNi Alloy Microstructure and the Mechanical Properties Caused by Repeated B2-B19′ Martensitic Transformations

Anna Churakova1,2(), Dmitry Gunderov1,2, Alexander Lukyanov2, Niklas Nollmann3   

  1. 1 Institute of Molecule and Crystal Physics RAS, 151 pr.Oktyabrya, Ufa 450075, Russia
    2 Ufa State Aviation Technical University, 12 K. Marx street, Ufa 450000, Russia
    3 Institute of Materials Physics, University of Münster, Wilhelm-Klemm Street10, 48149 Münster, Germany
  • Received:2015-03-25 Revised:2015-09-01 Online:2015-10-12 Published:2015-10-20


The influences of thermal cycling treatment in the temperature range of B2-B19 martensitic transformations (-150 to 150 °C) on the TiNi alloy structure and properties were studied. Different states named the initial coarse-grained (CG) state, the ultrafine-grained (UFG) state after ECAP (with a grain size of 200 nm), the state after ECAP and cold upsetting by 30% were considered. The results show that the microhardness and the strength increase in all the three states. According to the XRD analysis, a more significant increment in the dislocation density, resulting from thermal cycling, is observed in the UFG alloy than in the CG alloy.

Key words: Thermal cycling, TiNi alloy, Equal-channel angular pressing, Martensitic transformation