Neutron diffraction study of stress-induced martensitic transformation and variant change in Fe–Pd

Neutron diffraction spectra have been recorded in situ during tensile testing of polycrystalline Fe-30.5 at % Pd at a range of temperatures, in order to investigate stress-induced martensitic transformation and variant changes. The selective transformation of preferentially oriented austenite grains and martensite variants is identified and related to elasticity-based theory. Rietveld refinement is applied to determine the variation of elastic stiffness with temperature, revealing a significant increase in stiffness upon transformation to the martensite phase, in contrast to macroscopic measurements. © 2003 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.