Abstract: Alumina and carbon short fibers reinforced Al-12Si aluminum alloy ( Al₂O_3f +C_f/ZL109) hybrid composites were fabricated by squeeze casting .The tensile strength of the hybrid composites at room temperature was experimentally and theoretically analyzed .The rule-of-mixture (ROM)model to predict the tensile strength of the composite was then developed and modified, based on the effects of comprehensive factors on the property of metal-matrix composites, including the length change regularities of the two fibres, the respective tensile beha-vior and mechanism of the two fibres, the dislocation-strengthening resulting from thermal stress and the dispersion-strengthening of the fibres .Furthermore, a new model was established for the prediction of the tensile strength of the hybrid composites at room temperature .The theoretical tensile strength predicted by the new mo-del agrees well with the experimental results .

Key words: metal-matrix hybrid composites, strength prediction, theoretical model