Mechanical Properties and Mold Filling Capability of Al-Si-Mg Casting Alloy Fabricated by Lost Foam Casting Process

The lost foam casting process was used to fabricate Al-Si-Mg cast specimens, and the effects of the chemical composition and process variables on the tensile properties and the mold filling ability were investigated. Some porosity formation was observed in thick sections of the casting and better tensile properties were obtained for thin sections, presumably because of their lower porosity and the higher cooling rate. Tensile properties were not clearly enhanced by grain refining treatment with Ti; however, the elon-gation was significantly improved by Sr modification of the Al-Si-Mg alloy. The mold filling distance was generally proportional to the pouring temperature of the melt, and the distance was also increased by the addition of Ti.