The differential scanning calorimetric（DSC） and transmission electron microanalysis（TEM） techniques were used to study the kinetic process of precipitation in matrix ofcast SiCp/2024 composites.The results showed that precipitation reactions of GPzone and intermediate phase S’（Al2CuMg）in the composites were accelerated comparedwith SiC-free material,the peak temperatures of both reactions were decreased.Thereaction enthalpies of both the GP zone and intermediate phase S’ formation in thematrix were substantially decreased after the addition of SiC.TEM analysis found thatthe alloying element Mg segregated at the SiC/Al interfaces,and was depleted in thematrix near the interface.The precipitation-free zones（PFZ） and precipitation-sparsezones（PSZ） formed near the interfaces,as a results,the volume fraction of precipitatesin matrix was reduced.
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