Transferred Pressure and Shrinkage Cavity of Aluminum Alloys on Squeeze Casting

Abstract

  In squeeze castings, molten metal is compulsorily fed for shrinkage. The occurrence of the casting defects is therefore influenced by degree of the transferred pressure. In this study, the transfer ability of molten metal pressure in the squeeze castings of Al-Si alloys was investigated. The occurrence of shrinkage cavity was found to depend on the duration of the transferred pressure, not so much as the value of the transferred pressure. And the duration varied according to the Si contents of Al-Si alloys. For example, the duration on the castings of the eutectic Al-12Si alloy was longer than that of the hypoeutectic Al-6 % Si alloy. Because this duration was influenced by the solidification manner of Al-Si alloys, and the transfer ability of alloy solidified with the skin-formation type casting is higher than that of alloys solidified with mushy-formation type.