2134/5623 Houzheng Wu Houzheng Wu Steve G. Roberts Steve G. Roberts Brian Derby Brian Derby Ductile deformation in alumina/silicon carbide nanocomposites Loughborough University 2009 untagged Information and Computing Sciences not elsewhere classified 2009-12-08 15:11:06 Journal contribution https://repository.lboro.ac.uk/articles/journal_contribution/Ductile_deformation_in_alumina_silicon_carbide_nanocomposites/9404138 A transmission electron microscope study on cross sections obtained from ground and polished surfaces has revealed that ductile deformation is dominated by dislocations in alumina/silicon carbide nanocomposites containing 1, 5 and 10 vol% silicon carbide particles, and by twinning in unreinforced alumina. The dispersed silicon carbide particles in alumina/silicon carbide nanocomposites restrict the motion of dislocations. A dislocation pinning model is used to compare the possible mechanisms of deformation in alumina and the nanocomposites. Cr-fluorescence piezospectroscopy has been used to characterise the residual stress levels in the materials studied. The measured broadening of the Al2O3/Cr3+ fluorescence peak indicates a dislocation density of 7.3 - 9.7 x 1016 m-2 under the indentations in the nanocomposites, whilst the beneath indentations in alumina is 1-2 orders of magnitude smaller.