Using neutrons to investigate changes in strain partitioning between the phases during plastic yielding of calcite+halite composites

We have performed several room pressure and temperature uniaxial compression experiments on synthetic calcite+halite composites on the ENGIN-X beamline at the ISIS facility, UK, with a view to using the penetrating power of neutrons to monitor how strain partitioning between these phases changes as the halite undergoes plastic yielding. The principal dataset comes from samples for which the two phases were randomly intermixed but in which the volume fractions of the phases varied from 10 to 90% calcite. For samples with less than about 50% calcite, the strain partitioning between the phases was unaffected by halite yielding, but at higher calcite contents, load transfer from the halite to the calcite was initiated when the former yielded. The calcite deformed elastically but at high calcite contents (>80%) there was a switch from approximately homogeneous stress to homogeneous strain deformation within that phase. © 2006 Elsevier B.V. All rights reserved.