A transmission electron microscopy study of phase compatibility in low hysteresis shape memory alloys

Remi Delville (1) , Sakthivel Kasinathan (2) , Zhiyong Zhang (2) , V Humbeeck (3) , Richard Dick James (2) , Dominique Schryvers (4)

1 Physics
2 AEM - Department of Aerospace Engineering and Mechanics [Minneapolis]
3 MTM
4 Physics

Recent findings have linked low hysteresis in shape memory alloys with phase compatibility between austenite and martensite. In order to investigate the evolution of microstructure as the phase compatibility increases and the hysteresis is reduced, transmission electron microscopy was used to study the alloy system Ti_xNi_50-xPd_x where the composition is systemically tuned to approach perfect compatibility. Changes in morphology, twinning density and twinning modes are reported along with special microstructures occurring when the compatibility is achieved. In addition, the interface between austenite and a single variant of martensite was studied by high-resolution and conventional electron microscopy. The low energy configuration of the interface detailed in this article suggests that it plays an important role in the lowering of hysteresis compared to classical habit plane interfaces.

Mots clés: Physical Sciences

Remi Delville, Sakthivel Kasinathan, Zhiyong Zhang, V Humbeeck, Richard Dick James, et al.. A transmission electron microscopy study of phase compatibility in low hysteresis shape memory alloys. Philosophical Magazine, 2010, 90 (01-04), pp.177-195. ⟨10.1080/14786430903074755⟩. ⟨hal-00556063⟩