Introduction: Ultrasonic Additive Manufacturing (UAM), a rather new three-dimensional (3D) printing technology, uses ultrasonic energy to produce metallurgical bonds between layers of metal foils near room temperature . There is no melting of the parent foil in the UAM process. Instead, the bond is formed through mechanical strain input. Peak weld interface temperatures have been measured near 125 oC using fast response thermocouples  and solidification microstructure is absent at the bond . Intermittent of the additive stage, computer numerical control (CNC) machining is used to introduce internal features and for final machining. The no melting attribute of the process enables dissimilar metal joining without the formation of brittle intermetallic phases , welding of multiple copper and aluminum alloys, integration of temperature sensitive components, and fabrication of heat exchanger devices . UAM heat exchanger devices can be large or small and exhibit machined surface channels. These UAM specialties are exemplified in Figure 1.
Authors: Adam Hehr, Justin Wenning, and Mark Norfolk