In situ quantitative analysis of stress and texture development in forsterite aggregates deformed at 6 GPa and 1373 K

• Published in: Journal of applied crystallography Vol. 45; no. 2; pp. 263 - 271
• Main Authors: Bollinger, Caroline, Merkel, Sébastien, Raterron, Paul
• Format: Journal Article
• Language: English
• Published: 5 Abbey Square, Chester, Cheshire CH1 2HU, England International Union of Crystallography 01-04-2012
• Subjects: D-DIA; deformation; high pressure; lattice preferred orientation; olivine; residual stress; rheology; texture
• ISSN: 1600-5767; 0021-8898; 1600-5767
• DOI: 10.1107/S002188981200516X

The investigation of materials plastic properties at high pressure is a fast‐growing field, owing to the coupling of high‐pressure deformation apparatuses with X‐ray synchrotron radiation. In such devices, materials strain and strain rate are measured by time‐resolved radiography, while differential stress is deduced from the elastic response of the d spacing of the crystallographic planes as measured by X‐ray diffraction. Here a new protocol is presented, which allows the in situ measurement of stress and texture development in aggregates deformed at high pressure for experiments carried out with the recently installed ten‐element energy‐dispersive detector at the X17B2 beamline of the National Synchrotron Light Source (Brookhaven National Laboratory, Upton, NY, USA). Cycling deformation of a forsterite specimen was carried out at a pressure of ∼6 GPa and a temperature of ∼1373 K, using a deformation‐DIA apparatus. Diffraction peak energies are analysed in terms of differential stress and principal stress direction, while the intensities of peaks obtained at different azimuths are analysed in terms of lattice preferred orientation (LPO). The development and evolution of a marked LPO, with the (010) plane perpendicular to the compression axis, is observed in situ during the run and is confirmed by electron backscatter diffraction measurements on the run product.