8.5%SiC

p

/AZ91 D matrix composites were prepared by semi-solid stirring at 585 ℃ and holding at 595 ℃ as well as squeezing casting at 585 ℃. After solid solution treatment at 415 ℃ for 24 h and aging treatment at 220 ℃ for 8 h

the microstructure and mechanical properties of the composites prepared were investigated by OM

SEM

EDS and tensile testing.The results reveal that after squeezing casting and heat treatment

the microstructure and mechanical properties of the composites can be improved. After squeezing casting

grain morphology in the composites is refined to equiaxed structure

in which amounts of SiC particles occupy the grain boundary. After solid solution and aging treatment

amounts of lamellar Mg

17

Al

12

phase with a certain orientation can be observed in the microstructure of the composites. The tensile strength

elongation and hardness of the squeezing casting composites reach 191.06 MPa

1.75% and 143.4 HV

while those of ones after solid solution and aging treatment are 241.26 MPa

4.22% and 152.5 HV

respectively.