China Foundry (Aug 2009)
Effect of strontium and solidifi cation rate on eutectic grain structure in an Al-13 wt% Si alloy
Abstract
The influence of strontium addition and solidification rate on eutectic grain structure in a near-eutectic Al-Si alloy was investigated. The characteristic temperature of eutectic nucleation (TN), minimum temperature prior to recalescence (TM), and the growth temperature (TG) during cooling were determined by quantitative thermal analysis. All characteristic temperatures were found to decrease continuously with increasing Sr content and solidifi cation rate. Microstructural analysis also revealed that the eutectic grain size decreases with increasing Sr content and solidifi cation rate. Such eutectic grain refi nement is attributed to the increased actual under-cooling ahead of the liquid/solid interface during solidifi cation.
