Squeeze Casting of Hypereutectic Aluminum-Silicon Alloy Pistons

Squeeze casting has been used for the shaping of comparatively large sized pistons made of hypereutectic aluminum-silicon alloys(silicon content between 16% to 20%).95% of the piston blanks made were found to be of excellent quality.Normaltest and extremum difference analysis were used in devising an ideal processing scheme for the squeeze casting.It has also been proved that the principal process parameter,i.e.the per unit area pressure,has an obvious influence on the exterior look and the lowmagnification structure of the piston blank, but its influence wasn't so marked on the microstructure of the alloy, nor on the mechanical properties.After heat treatment ,the mechanical quality indices of the piston blank reached or even surpassed those ofcomparable products made in Germany.Besides,it proved to have good cuttingProperties.