Modification of Al-Mg_2Si In-Situ Composite by Boron

摘要

In this work, the effect of Boron on the microstructural development of a thick section in-situ Al-15%Mg2Si composite, casted in a thick section mould, were investigated. It was found from optical and scanning electron microscope (SEM) images that Mg2Si particles size significantly decreased by Boron addition and that the amount of alpha phase surrounding the Mg2Si particles increased. Meanwhile with the addition of B, the morphology of pseudo-eutectic Al-Mg2Si phase was changed from fibrous to fine Chinese script in cells separated with the alpha phase. Moreover, a small amount of B-containing compounds were formed as a result of B additions.