In situ neutron diffraction study of metals under external mechanical loading

Abstract

High-resolution neutron strain scanners in NPI were recently equipped with a deformation rig enabling both tensile and compressive tests of materials. Employing this instrumentation can bring new information concerning deformation process in various polycrystalline materials. Multiphase materials are particularly suitable for such experiments because strain states could be determined in situ by diffraction in each individual phase yielding thus frequently a scheme of phase interaction in deformation process [1]. Microstructural characteristics of individual phases such as elastic lattice strain or microstrain can be determined from the profile analysis (position, width and shape of the diffraction peaks corresponding to each phase). These characteristics can be associated with macroscopic stresses and strains. In this paper, results of the investigation of the CuAlZnMn shape memory alloy exhibiting stress-induced martensitic transformation is shown to demonstrate the applicability of the experimental technique.