Abstract: Experiments were conducted to determine the residual stresses with X-ray diffraction in the ma- trix of a SiC/Al composite after different thermal treatments,and to investigate the stress-strain characteristics and fracture behaviour of the com- posite.It was found that there existed a tensile residual stress in the matrix and both thermal cy- cling between room temperature and 350℃ and low temperature treatment in liquid nitrogen reduced the residual stress.The results of the strength differential effect and Bauschinger effect were con- sistent with the results of residual stress measurements.The tensile residual stresses in the Al matrix enhanced the strength differential effect.The magnitude of Bauschinger effect is greater for a test initially started in compression than that in tension.

Key words: metal matrix composites, residual stress, deformation behaviour