%0 journal article
%@ 1359-6454
%A Reul, A., Lauhoff, C., Krooß, P., Somsen, C., Langenkämper, D., Gutmann, M.J., Pedersen, B., Hofmann, M., Gan, W.M., Kireeva, I., Chumlyakov, Y.I., Eggeler, G., Niendorf, T., Schmahl, W.W.

%D 2022
%J Acta Materialia

%P 117835 
%R doi:10.1016/j.actamat.2022.117835
%T On the impact of nanometric γ’ precipitates on the tensile deformation of superelastic Co49Ni21Ga30
%U https://doi.org/10.1016/j.actamat.2022.117835
 
%X Results are presented reporting on the martensite domain variant selection and stress-induced martensite morphology in [001]-oriented superelastic Co49Ni21Ga30 shape memory alloy (SMA) single crystals under tensile load. In situ neutron diffraction, as well as in situ optical- and confocal laser scanning microscopy were conducted focusing on three differently treated samples, i.e. in the as-grown, solution-annealed and aged condition. An aging treatment performed at 350 °C promotes the precipitation of nanoprecipitates. These second phase precipitates contribute to an increase of the number of habit plane interfaces, while reducing lamellar martensite plate thickness compared to the as-grown and solution-annealed (precipitate free) samples. During tensile loading, all samples show a stress-induced formation of martensite, characterized by one single domain variant (“detwinned”) and one set of parallel habit planes in a shear band. The results clearly show that γ’ nanoprecipitates do not necessarily promote multi-variant interaction during tensile loading. Thus, reduced recoverability in Co-Ni-Ga SMAs upon aging cannot be solely attributed to this kind of interaction as has been proposed in literature so far.