In situ neutron diffraction study of metals under external mechanical loading

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 deform ation process in various polycrystalline materials. Multiphase materials ar e particularly suitable for such experiments because strain states could be determined in situ by diffraction in each individual phase yielding thus f requently a scheme of phase interaction in deformation process [1]. Microst ructural characteristics of individual phases such as elastic lattice strai n or microstrain can be determined from the profile analysis (position, wid th and shape of the diffraction peaks corresponding to each phase). These c haracteristics 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 demonstra te the applicability of the experimental technique. (C) 2000 Elsevier Scien ce B.V. All rights reserved.