Effect of hexagonal martensite on the TRIP-assisted deformation of HEAs

A system of high-entropy alloys has been developed that exhibit the transformation induced plasticity (TRIP) effect, improving strength and ductility. The alloys show the formation of hexagonal epsilon-martensite, which while detrimental in steels appears to be a valuable toughening mechanism in these alloys. However, the SEM level characterization used so far was not adequate to quantify the transformation as a function of strain, and the role of various starting microstructural features is not understood. Neutron diffraction on Engin-X is sought to elucidate the behaviour.