Hard X-ray studies of stress-induced phase transformations of superelastic NiTi shape memory alloys under uniaxial load (bibtex)

by M. Hasan, W.W. Schmahl, K. Hackl, R. Heinen, J. Frenzel, S. Gollerthan, G. Eggeler, M. Wagner, J. Khalil-Allafi, A. Baruj

Abstract:
We examined the texture evolution in a superelastic Ni50.7Ti49.3 (numbers indicate at.%) alloy under applied uniaxial stress using high-energy synchrotron X-ray diffraction in transmission geometry. Texture information is identified from the intensity variations along Debye–Scherrer rings recorded on area detector diffraction images. The 1 1 0A austenite plane normals are aligned in the rolling direction and 2 0 0A is in the transverse direction. Due to the B2--B19' lattice correspondence, the 1 1 0A peak splits into four martensite peaks 0 2 0M, -1 1 1M, 0 0 2M and 1 1 1M. The stress-induced martensite is strongly textured from twin variant selection in the stress field with 0 2 0M aligned in the loading direction while the maxima corresponding to -1 1 1M, 0 0 2M and 1 1 1M are at 60°,67° and 75° from the loading direction. (B19' unit cell setting: a = 2.87 Å, b = 4.59 Å, c = 4.1 Å, γ = 96.2°).A comparison between the experimental and recalculated distribution densities for the polycrystalline NiTi shows a reasonable agreement. In addition, we compare our experimental results with a micromechanical model which is based on total energy minimization. In this case, we also observe an overall agreement.
View PDF
Reference:
Hasan, M., Schmahl, W.W., Hackl, K., Heinen, R., Frenzel, J., Gollerthan, S., Eggeler, G., Wagner, M., Khalil-Allafi, J., Baruj, A.: Hard X-ray studies of stress-induced phase transformations of superelastic NiTi shape memory alloys under uniaxial load, Materials Science and Engineering: A 481-482, 414-419, 2008.
Bibtex Entry:
@Article{Hasan2008,
  author   = {Hasan, M. and Schmahl, W.W. and Hackl, K. and Heinen, R. and Frenzel, J. and Gollerthan, S. and Eggeler, G. and Wagner, M. and Khalil-Allafi, J. and Baruj, A.},
  journal  = {Materials Science and Engineering: A},
  title    = {{Hard {X}-ray studies of stress-induced phase transformations of superelastic {NiTi} shape memory alloys under uniaxial load}},
  year     = {2008},
  issn     = {09215093},
  pages    = {414--419},
  volume   = {481-482},
  abstract = {We examined the texture evolution in a superelastic Ni\textsubscript{50.7}Ti\textsubscript{49.3} (numbers indicate at.%) alloy under applied uniaxial stress using high-energy synchrotron X-ray diffraction in transmission geometry. Texture information is identified from the intensity variations along Debye–Scherrer rings recorded on area detector diffraction images. The 1 1 0\textsubscript{A} austenite plane normals are aligned in the rolling direction and 2 0 0\textsubscript{A} is in the transverse direction. Due to the B2--B19' lattice correspondence, the 1 1 0\textsubscript{A} peak splits into four martensite peaks 0 2 0\textsubscript{M}, -1 1 1\textsubscript{M}, 0 0 2\textsubscript{M} and 1 1 1\textsubscript{M}. The stress-induced martensite is strongly textured from twin variant selection in the stress field with 0 2 0\textsubscript{M} aligned in the loading direction while the maxima corresponding to -1 1 1\textsubscript{M}, 0 0 2\textsubscript{M} and 1 1 1\textsubscript{M} are at 60°,67° and 75° from the loading direction. (B19' unit cell setting: a = 2.87 Å, b = 4.59 Å, c = 4.1 Å, γ = 96.2°).A comparison between the experimental and recalculated distribution densities for the polycrystalline NiTi shows a reasonable agreement. In addition, we compare our experimental results with a micromechanical model which is based on total energy minimization. In this case, we also observe an overall agreement.},
  doi      = {10.1016/j.msea.2007.02.156},
  keywords = {Cold rolled B2 austenite, NiTi, Stress-induced martensite, Superelasticity, Twin variant texture},
  url      = {http://linkinghub.elsevier.com/retrieve/pii/S0921509307012531},
}
Powered by bibtexbrowser