Microsecond-scale depth-resolved detection of the martensitic phase transformation at high driving forces

We propose an experiment to study the intrinsic dynamics of the fast martensitic transformation in shape memory alloys. The kinetic laws of the martensitic transformation remain an open fundamental question due to the lack of experimental tools for inducing and tracking the process at the high-driving-force regime with sufficient time resolution. The unique state-of-the-art CdTe Keck-PAD detector, allows us to fully utilize ESRF capabilities and break through current technological barriers of X-ray detection. The novel CdTe detector technology has superb quantum efficiency at energies over 40 keV and sub-microsecond time resolution, enabling a depth-resolved investigation of the phase transformation in typical high-quality NiTi wires of various diameters. Gradual increase of the X-ray energy allows for radially resolved detection by variation of penetration depth of austenite-martensite interfaces in the axisymmetric nano-crystalline material along different radii at different times.