AC4CH alloy castings were produced by squeezing casting

and effects of casting pressure

filling velocity and filling distance on microstructure and properties of the castings were investigated. Microstructure of the squeezed AC4CH parts is composed of α-Al phase and eutectic Si phase

and the grain size in the microstructure is obviously refined with increasing in filling distance. With increasing in filling pressure and filling velocity

eutectic Si phase is decreased with more uniform distribution

and the tensile strength and yield strength of the parts are greatly improved

however

tensile strength is increased slowly wien the filling pressure exceeds a critical value.