How Ultrasonic Additive Manufacturing Works
The UAM process involves building up solid metal objects through ultrasonically welding a succession of metal tapes into a three-dimensional shape, with periodic machining operations to create the detailed shape of the resultant objects. The figure at right shows a rolling ultrasonic welding system, consisting of two ultrasonic transducers and the (welding) horn. The vibrations of the transducer are transmitted to the disk-shaped welding horn, which in turn creates an ultrasonic solid-state weld between the thin metal tape and a base plate. The continuous rolling of the horn over the plate welds the entire tape to the plate.
The process of ultrasonic metal welding is one in which ultrasonic vibrations create a friction like relative motion between two surfaces that are held together under pressure. This action, in turn, causes shearing and plastic deformation between asperities of the opposing surfaces, which disperses surface oxides and contaminants. As the asperities collapse, metal-to-metal contact is increased creating solid state bonding between the parts through heat and pressure.