MICROSTRUCTURE, STRAIN FIELDS AND FLOW-STRESS IN DEFORMED METAL-MATRIX COMPOSITES

An experimental study of local orientations around whiskers in deforme d metal matrix composites has been used to determine the strain gradie nts existing in the material following tensile deformation. These stra in fields have been represented as arrays of geometrically necessary d islocations, and the material flow stress predicted using a standard d islocation hardening model. Whilst the correlation between this and th e measured flow stress is reasonable, the experimentally determined st rain gradients are lower by a factor of 5-10 than values obtained in p revious estimates made using continuum plasticity finite element model s. The local orientations around the whiskers contain a large amount o f detailed information about the strain patterns in the material, and a navel approach is made to representing some of this information and to correlating it with microstructural observations. (C) 1998 Acta Met allurgica Inc. Published by Elsevier Science Ltd. All rights reserved.