In-situ observation of intragranul strain and mosaicity changes during electrochemical hydrogenation of B2-TiNi: Formation of B19 and hydrat

Near-equiatomic TiNi alloys with thermoelastic martensite transformations, shape memory effect and superelasticity are used in engineering and medicine. However, when applied, the alloys reveal hydrogen embrittlement, corrosion, influence of absorbed hydrogen on their martensite transformations and functional properties. Currently, it is not understood how the hydrogen diffusion into TiNi is influenced by material residual strain distribution and local microstructure. The aim of this DFXM experiment is to perform the first in-situ characterization of hydrogen loading into a coarse-grained TiNi and quantify changes in intragranular (compressive) strain distribution, mosaicity and (indirectly also) in the formation of B19 and hydrides phases during in-situ electrochemical loading. The results will reveal the susceptibility of grains of particular orientation, grain boundaries, twins and defects to the hydrogen loading, which will be for the first time observed at the intra-grain level.