Microstructure and property of rheocasting aluminum-alloy made with indirect ultrasonic vibration process

This paper reports a new slurry-making process with indirect ultrasonic vibration (IUV), in which the horn is vibrated under the outside of the metallic cup containing alloy melt. Semisolid slurry of A356 Al alloy was prepared by this process, and the effects of IUV treatment time on the morphology of the primary α-Al phase and mechanical properties of rheo-diecasting samples were studied. The results indicate that excellent semisolid slurry of A356 Al alloy could be obtained within 50 s by applying IUV near its liquidus temperature. The sample rheocasted with the slurry made by IUV for 50 s had the maximum tensile strength and elongation, which were 254 MPa and 7.5% respectively.

► Semisolid slurry of A356 Al alloy was made by indirect ultrasonic vibration (IUV). ► IUV treatment time had significant effect on the mechanical properties of A356 alloy. ► Rheocasting alloy had higher mechanical properties than conventional diecasting one.