EFFECTS OF Sr AND B INTERACTIONS IN HYPOEUTECTIC Al-Si FOUNDRY ALLOYS

摘要

Strontium is the most widely used and a very effective element for modifying the morphology of eutectic silicon, while boron is commonly present in commercial grain refiners used for Al-Si alloys. Recent work on the combined additions of Sr and Al-B master alloys and of Sr and A15Ti1B master alloy has suggested that negative interactions occur between Sr and B added through the grain refiners. However, the effects of and mechanisms for such negative interactions are not fully understood. This paper documents the experimental work and results aimed at determining the effects of Sr and B interactions on the solidification of hypoeutectic Al-Si foundry alloys. The mechanisms responsible for such negative interactions are further discussed.