Publication detail

On the effect of deformation twins on stability of B19' structure in NiTi martensite

ŠESTÁK, P. ČERNÝ, M. POKLUDA, J.

Czech title

K vlivu deformačních dvojčat na stabilitu struktury B19' v martensitu NiTi

English title

On the effect of deformation twins on stability of B19' structure in NiTi martensite

Type

journal article in Web of Science

Language

en

Original abstract

The present study is focused on discrepancy between theoretically predicted (base centered orthorhombic B33) and experimentally observed (monoclinic B19') ground state structures of NiTi martensite. In particular, we deal with a hypothesis on possible effect of presence of twins on the martensite structure. Several models of (100) twins in NiTi martensite (representing several twin densities) are studied from first principles. Computational supercells are fully optimized in order to reach almost stress-free state for each twin model. Our results show that the presence of twins has a significant influence on crystal geometry that tends to stabilize B19' structure rather than the B33 one, at least for higher twin densities.

Czech abstract

Tato studie je zaměřena na rozpor mezi teoreticky předpovězenou (B33) a experimentálně pozorovanou (monoclinic B19 ") základní strukturou NiTi martenzitu. Zejména jsme se zaměřili na hypotézu o možném vlivu přítomnosti dvojčat ve struktuře martenzitu. Některé modely (100) dvojčat v NiTi martenzitu (zastupující několik hustot dvojčat) jsou studovány z prvních principů. Výpočetní supercelly jsou plně optimalizovány tak, aby bylo dosaženo téměř uvolněného stavu pro každý model dvojčete. Naše výsledky ukazují, že přítomnost dvojčat má významný vliv na geometrii krystalu, který má tendenci ke stabilizaci B19 "struktury, spíše než B33, alespoň pro vyšší hustoty dvojčat.

English abstract

The present study is focused on discrepancy between theoretically predicted (base centered orthorhombic B33) and experimentally observed (monoclinic B19') ground state structures of NiTi martensite. In particular, we deal with a hypothesis on possible effect of presence of twins on the martensite structure. Several models of (100) twins in NiTi martensite (representing several twin densities) are studied from first principles. Computational supercells are fully optimized in order to reach almost stress-free state for each twin model. Our results show that the presence of twins has a significant influence on crystal geometry that tends to stabilize B19' structure rather than the B33 one, at least for higher twin densities.

Keywords in Czech

nitinol, dvojčatění, stabilizace struktury, ab-initio výpočty

Keywords in English

nitinol; twinning; structure stabilization; ab initio calculations

RIV year

2014

Released

12.02.2014

Publisher

Elsevier

ISSN

0927-0256

Volume

87

Number

2

Pages from–to

107–111

Pages count

5

BIBTEX


@article{BUT105276,
  author="Petr {Šesták} and Miroslav {Černý} and Jaroslav {Pokluda},
  title="On the effect of deformation twins on stability of B19' structure in NiTi martensite",
  year="2014",
  volume="87",
  number="2",
  month="February",
  pages="107--111",
  publisher="Elsevier",
  issn="0927-0256"
}