Ultrasonic Measurements and Resonance Predictions of Hybrid-Additive Manufacturing

Hybrid-additive manufacturing (AM) combines 3D printing with energy sources or manufacturing techniques — like milling or peening — to create functionally graded materials. Each hybrid step or layer refines grain size, increases dislocation density, and, in turn, modifies residual stresses. The ability to fine-tune a part's material properties at specific locations offers exciting possibilities for part design and performance but also makes nondestructive quality inspection more complex. Current methods of measuring residual stress in additively manufactured components are limited in their sensitivity, or they are destructive measurements. The research presented focuses on understanding how these material changes affect ultrasonic signals, using both experiments and computer modeling and building reliable connections between the two. Ultrasonic measurements along with resonant ultrasound spectroscopy (RUS) provide a potential avenue to measure residual stresses in hybrid-additively manufactured components. These measurements would allow for a non-destructive material characterization currently not available in industry.