Feeding and Distribution of Porosity in Cast Al-Si Alloys as Function of Alloy Composition and Modification

摘要: Unmodified, Na-modified, and Sr-modified castings of Al-7 pct Si Al-12.5 alloys were cast in molds which it was possible to create different cooling conditions. It is shown how solidification influences the distribution porosity at surface center as a function modification content sand- chill-cast samples. Eutectic modification, content, conditions have great impact on porosity. Unmodified Na-modified are more easily fed with tending congregate near centerline casting, while solidify mushy manner that creates homogeneous casting. The amount highest alloys, lower lowest unmodified alloys. size porosity-free layer effectiveness feeders greater made steel chills due increased thermal gradients consequent increase directionality solidification.