The trial-manufacturing of the carrier was described

and origination of crack、cold-shut and misrun in the sand mold gravity casting was analyzed.Crack is resulted from complicated shape with unevern wall thickness

and the dis-rational processing design is responsible for cold-shut defects.Un-rational structure and processing design result in the misrun defects.Through adopting optimizing processing parameters

such as liquid aluminum alloy quality

pouring velocity

filling pressure

pouring time and exhausting channel

some defects

such as crack

cold shut

misrun

in the carrier

can be eliminated effectively.