INFLUENCE OF LANTHANUM ON THE STRUCTURE AND MECHANICAL PROPERTIES OF ALUMINUMSILICON EUTECTIC ALLOY

摘要

This paper deals with the characteristics of silicon modification with lanthanum of Al-Si eutectic alloy insand mold and metal mold with optical microscopy,scanning electron microscopy,electron microprobe andX-ray diffractometer.It is found that the amount of lanthanum,liquid alloy condition,holding time and stir-ring liquid influence the modification of silicon.The modification of silicon with lanthanum is of longeffectiveness and has a“incubation time”.The modification can improve the ductility(δ_s)and tensile strength(σ_b)of the alloy,but their maximum values are not corresponding to the same amount of lanthanum.