| About this Abstract |
| Meeting |
MS&T22: Materials Science & Technology
|
| Symposium
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Processing and Performance of Materials Using Microwaves, Electric and Magnetic Fields, Ultrasound, Lasers, and Mechanical Work – Rustum Roy Symposium
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| Presentation Title |
In-situ Diffraction of Ultrasonically-modified Phase Evolution in a Ternary Al-Si-Mg Alloy |
| Author(s) |
Katherine Rader, Jonova Thomas, Chihpin Chuang, Dileep Singh, Adrian Sabau, Aashish Rohatgi |
| On-Site Speaker (Planned) |
Katherine Rader |
| Abstract Scope |
Ultrasonic melt processing (USMP) can refine the as-cast microstructure of aluminum alloys by changing the grain morphology from coarse dendritic grains to finer, non-dendritic grains. Recently published investigations utilized in-situ X-ray imaging techniques to provide fundamental evidence of the mechanisms controlling ultrasonically-induced microstructural refinement. This study expands on these previous studies by conducting in-situ experiments using time-resolved X-ray diffraction. Experiments were conducted at the Advanced Photon Source on beamline 1-ID using the high-speed detector system, which is capable of recording X-ray diffraction scans at rates of up to 250 Hz. Ultrasound was applied at a 20 kHz frequency to a molten ternary Al-Si-Mg alloy as it solidified. Phase nucleation and growth during solidification, both with and without the presence of ultrasonic excitation, were characterized. These data test various hypotheses regarding the mechanisms that govern ultrasonication-induced microstructural refinement, such as enhanced nucleation and dendrite fracture, expanding the fundamental knowledge of USMP. |