High-energy synchrotron x-ray diffraction for in situ study of phase transformation in shape-memory alloys

This overview highlights very recent progress on the application of high-energy x-ray diffraction for in situ study of the phase transformation of shape-memory alloys. The advantages of the synchrotron-based high-energy x-ray diffraction method and the experimental setup for exploring the phase-transition behavior of single crystals or textured polycrystalline materials under multiple external fields are described. Experimental investigations on the influence of external stress, magnetic, and thermal fields on the phase-transformation behaviors of thermal and ferromagnetic shape-memory alloys, and nanowire-reinforced shape-memory composites are also summarized. Special attention is given to recent scientific issues related to the microscopic "memory" of martensite variants, transition kinetics, magnetic field-induced selection of variants, magnetic field-driven phase transition, and superelasticity.