Micromechanical study on the morphology of martensite in constrained zirconia

Size effects on the martensitic phase transformation of NiTi nanograins

“…In the case of shape memory alloys, small residual strains of the self-accommodating martensite are accommodated elastically. Both the transformation strains of the variants and the interfaces formed between them determine the typical size of the variants (Khachaturyan et al, 1991;Yan et al, 1997;Hackl et al, 2004). It is important to note that the transformation strains and the formation of interfaces oppose the transformation and cause a transformation barrier since they increase the energy of the transformation.…”

An eigenstrain approach to predict phase transformation and self-accommodation in partially stabilized zirconia

“…In [17] the overall strain was accounted for by assuming that the individual twins which form a twin pair can have different height. Here, only pairs of twins consisting of individual twins of equal height are considered and a different approach is used to capture the overall shear strain.…”

“…Further, according to [4,17] the twinning eigenstrainẽ 12 is assumed to be equal to the transformation strainẽ 12 .…”

“…The Gibbs free energy of the system in the transformed state without self-accommodation is given by (17), whereas the system with an additional twinned structure has the Gibbs free energy…”

“…Our method is based on the solution for eigenstresses due to prescribed eigenstrains given in [16]. Similar investigations were performed already in [17]. However, only circular inclusions were considered and the strain energies for the different morphologies were computed numerically due to the lack of an analytical solution.…”