Shape Change and Crystal Orientation of B19 Martensite in Equiatomic TiPd Alloy by Isobaric Test

We investigated the texture and the shape change in the equiatomic TiPd alloy, and discussed the relationship between the shape change and the atomic movements associated with martensitic transformation. Thermomechanical analyzer tests indicate that the direction of the shape change was different between the 0 degrees and 90 degrees samples, cutting out parallel and perpendicular to the hearth side of button ingot, respectively. In the 0 degrees sample, shrinking and expansion were observed during the reverse and forward martensitic transformations, respectively, whereas the opposite tendency was confirmed in the 90 degrees sample compared to the 0 degrees sample. During the isobaric test, the martensitic variants were oriented to a (010) plane with compressive loading, and the B2 parent phase crystals also became coarse. There is a close relationship between the shape change due to the crystal orientation by the isobaric test and the shear-shuffling direction due to martensitic transformation.