Orientation Dependence of Functional Properties in Heterophase Single Crystals of the Ti36.5Ni51.0Hf12.5 and Ti48.5Ni51.5 Alloys

E. Yu Panchenko, Yu I. Chumlyakov, N. Yu Surikov, A. I. Tagiltsev, N. G. Vetoshkina, K. S. Osipovich, H. Maier, H. Sehitoglu

Research output: Contribution to journalArticlepeer-review

Abstract

The features of orientation dependence of stress-induced thermoelastic B2–(R)–B19′-martensitic transformations in single crystals of the Ti48.5Ni51.5 and Ni51.0Ti36.5Hf12.5 (at.%) alloys, which contain disperse particles of the Ti3Ni4 and H-phase, respectively, are revealed along with those of their shape-memory effects (SME) and superelasticity (SE). It is experimentally demonstrated that irrespective of the crystal structure of disperse particles measuring more than 100 nm, for their volume fraction f > 16% there is a weaker orientation dependence of the reversible strain in the cases of manifestation of SME and SE. In the orientations of Class I, wherein martensitic detwinning introduces a considerable contribution into transformation strain, the values of SME |εSME| and SE |εSE| decrease by over a factor of two compared to the theoretical lattice strain value |εtr0| for a B2–B19′-transformation and the experimental values of reversible strain for quenched TiNi crystals. In the orientations of Class 2, wherein detwinning of the martensite is suppressed as is the case in quenched single-phase single crystals, the reversible strain is maintained close to its theoretical value |εtr0|. Micromechanical models of interaction between the martensite and the disperse particles are proposed, which account for the weaker orientation dependence of |εSME| and |εSE| due to suppression of detwinning of the B19′-martensite crystals by the particles and a transition from a single-variant evolution of the stress-induced martensitic transformations to a multiple-variant evolution of transformations in the cases of increased size of the particles and their larger volume fractions.

Original languageEnglish (US)
Pages (from-to)1534-1543
Number of pages10
JournalRussian Physics Journal
Volume58
Issue number11
DOIs
StatePublished - Mar 1 2016

Keywords

  • disperse particles
  • shape memory effect
  • single crystals
  • superelasticity
  • thermoelastic martensitic transformations

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Fingerprint

Dive into the research topics of 'Orientation Dependence of Functional Properties in Heterophase Single Crystals of the Ti<sub>36.5</sub>Ni<sub>51.0</sub>Hf<sub>12.5</sub> and Ti<sub>48.5</sub>Ni<sub>51.5</sub> Alloys'. Together they form a unique fingerprint.

Cite this