|About this Abstract
|2022 TMS Annual Meeting & Exhibition
|Late News Poster Session
|Ultrasonically-induced Microstructural Refinement during Casting of an Al-Si-Mg Alloy
|Katherine Rader, Jens Darsell, Jon Helgeland, Nathan Canfield, Aashish Rohatgi
|On-Site Speaker (Planned)
Ultrasonic melt processing of aluminum alloys is of interest to improve the mechanical properties of cast automotive components through local microstructural refinement. In this study, ultrasonic vibrations were applied during solidification to a commercial Al-Si-Mg alloy cast in a graphite mold. Optical microscopy and electron backscatter diffraction were used to characterize the resultant microstructures with respect to grain size and morphology. Material that was cast without ultrasonication has a coarse dendritic microstructure with a mean grain size of 155 Ám and a mean secondary dendrite arm spacing of 23 Ám. Material that was ultrasonically modified has a non-dendritic microstructure with two distinct morphologies: (1) globular grains with a mean grain size of 19 Ám and (2) highly-refined grains with a mean grain size of 9 Ám. These non-dendritic microstructures demonstrate the ability of ultrasound applied during solidification to both refine the microstructure and modify the conventional dendritic morphology.
|Aluminum, Solidification, Other