Abstract:
The effect of rare earth element La on microstructure and mechanical properties of A356 aluminum alloys for automobile wheel hub was investigated by optical microscope, scanning electron microscope and tensile testing machine. The results show that the primary phase α-Al in the A356 aluminum alloy was refined after rare earth element La added. The morphology of eutectic Si changed from coarse acicular or lath-like into tiny fibrous. The mean area and aspect ratio of eutectic Si reduced from 126
μm
2 and 18.2 to 7.8
μm
2 and 1.8, respectively. AlSiLa intermetallic compound was obtained in the A356 aluminum alloy after rare earth element La added. The tensile strength and elongation increased first and then decreased with the increase of content of rare earth element La in the aluminum alloy. When the mass fraction of rare earth element La was 0.6%, the aluminum alloy had the maximum tensile strength and elongation which were 215 MPa, 5.4%, respectively.