60%SiC particles（volume fraction）reinforced 6061 aluminum alloy composites were fabricated by direct electro thermal vacuum forming process.The effects of solid solution and aging treatment on flexural strength and hardness of the composite prepared were investigated

and the optimized heat treatment process parameters were presented.The influences of surface modification of SiC particles on the mechanical properties of the composites were analyzed.The result reveal that with the solid solution

the mechanical properties of the composites can be improved

where the maximum hardness and flexural strength can be obtained at 530℃for 1 hand aging at 175℃for 15 h.Due to high temperature oxidation and mixing pickling pretreatment

SiC particles are passivated

which can improve uniformity of particle distribution in the matrix and improve the interfacial bonding of SiC particles and aluminum matrix interface

so the porosity is decreased

and the flexural strength and coefficient of thermal expansion are increased.In addition

the performance of the composites with SiC particle after pickling is better than that of the corresponding oxidation state.