Strain tensor development in a single grain in the bulk of a polycrystal under loading

First results are presented on the development of the elastic strain tensor in a single embedded grain during tensile loading of a copper sample. The technique is based on the use of focused high-energy X-rays from a synchrotron source. Measurements are performed by the rotation method, and automated indexing routines are used to group reflections belonging to a single grain. In total. 17 reflections were monitored as a function of tensile load. At each load level three elements of the strain tensor were fitted using a singular value decomposition routine for over-determined linear systems. Sources of systematic error are discussed, and a method for extending the technique towards simultaneous measurements of ensembles of grains is outlined. (C) 2002 Published by Elsevier Science Ltd on behalf of Acta Materialia Inc.