Effects of 0.12%Sr and different RE addition

such as 0

0.12%

0.24%

0.36%

0.48% and 0.60%

on microstructure and mechanical properties of ZL101 alloys with 1.2% Fe were investigated by optical microscope（OM）

X-ray diffraction（XRD）analysis

and INSTRON5882 EUMTS.The results showed that at a fixed Sr addition

the morphology of β-Fe phases in ZL101 alloys can be obviously improved with RE and Sr compound addition

and its structure is converted form needle-like into fine short rod.In the meantime

α-Al grains are refined and eutectic silicon is transformed into granular in the alloy after T6 heat treatment.The proper RE can improve mechanical properties of Al-Si alloys with high Fe content modified by Sr

and the increase of elongation is very slight.With addition of 0.36% RE +0.12% Sr in the alloys

the tensile strength of alloy after T6 heat treatment can reach the maximum 213 MPa

increased by 26.8% compared to 168 MPa of corresponding as-cast alloy.