Ultrasound, Oxide, and Oxygen: Microscale Mechanisms for Next-Generation Alloy Casting

More than 90 percent of U.S. manufactured goods contain cast metal components made with a process involving multiple steps, which include melting of the original metal, and solidification in casts. The commercial viability and energy efficiency of the entire operation require controlling and predicting product quality while maximizing the rate of casting. Unfortunately, measuring the properties of the melt during processing is difficult, and to date quality tests occur only after solidification. This award supports research aimed at providing a new tool to evaluate the melt properties using sound waves at very high frequency (ultrasound). The anticipated results are expected to enable real-time monitoring of the casting process, and lead to new processing methods that will increase the energy efficiency of casting.

In metal casting, precise control of the melt properties prior to solidification can be achieved after identifying and characterizing features like grains, inclusions, and bubbles. Ultrasound metrology could track those features, while also imaging solidification fronts and measuring melt flow. Unfortunately, prior implementations of ultrasound in liquid metal have often been unreliable and intermittent. The physical mechanisms impeding ultrasound metrology are not understood. This collaborative project will couple advanced physical and chemical science to enable real-time imaging and flow measurement via ultrasound metrology, before solidification. Combining electrochemical and ultrasound techniques for melt measurements, the project will determine the microscale mechanisms of interaction among ultrasound, metal, oxide, and dissolved gas in order to enable the further development of real-time monitoring of molten metal properties.