Effect of (La+Yb) addition on the fluidity of an A356.2 aluminum alloy

Abstract

ABSTRACT The effect of mixed rare earth (La+ Yb) addition on the fluidity of A356.2 was investigated by fluidity tests, optical microscope (OM), environmental scanning electron microscope (ESEM) with energy diffraction spectrum (EDS) and X-ray diffraction (XRD). Varying amounts of (La+ Yb) addition were tested, 0%，0.3%，0.6%, and 0.9% (wt.%). The fluidity of A356.2 was improved with the addition of mixed rare earth (La+ Yb). The fluidity length of the A356.2 + 0.6% (La+ Yb) alloy (670mm) was increased by 19% compared to that of A356.2 (565mm). The fluidity of the alloy was related to the morphology of α-Al and Al8Si6Mg3Fe（Fe phase）in the alloy. A refined microstructure of the alloy corresponded with better fluidity. A higher pouring temperature also improved fluidity. However, this trend declined when the pouring temperature increased above 730°C.