Bubbling up: Uncovering melt pool dynamics in metal manufacturing

Using high-speed X-ray imaging, a team of researchers led by Christopher Kube, associate professor of engineering science and of acoustics at Penn State, captured footage of a cross-section of liquid metal as it cooled. Their results confirmed longstanding hypotheses in the field that through local pressure changes, ultrasonic vibrations encourage air bubbles to increase in number, enlarge, migrate to the surface of a melt pool and pop — increasing the quality of the finished product.