Relaxation of residual stress in MMC after combined plastic deformation and heat treatment

Neutron Diffraction shows that plastic pre-deformation and heat treatments have opposite effects on the residual stress in Al-SiCp composites. The thermal micro residual stress is relaxed or even reversed by pre-strains above 0.2%, but restored by heat treatments. The sense of relaxation changes above 400 degreesC (the mixing temperature). (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.