It's a technique innovated by Fabrisonic company, which is a solid-state 3D-printing process for metals that uses sound waves to merge layers of metal foil. The process produces true metallurgical bonds with full density and works with a variety of metals—including but not limited to aluminum, copper, stainless steel, and titanium.
The UAM process involves building up of solid metal objects by ultrasonically welding a succession of metal tapes into a three-dimensional shape, to create the detailed features of the resultant object. The rolling ultrasonic welding system consists of ultrasonic transducers and a (welding) horn. The vibrations of the transducers are transmitted to the disk-shaped welding horn, which in turn creates an ultrasonic solidstate weld between the thin metal tape and baseplate. The continuous rolling of the horn over the plate welds the entire tape to the plate.
By welding a succession of tapes, first side-by-side and then one on top of the other (making sure to stagger layers so that the seams do not overlap), it is possible to build a solid metal part. A machining operation adds features to the part, removes excess tape material. Thus, the so-called “additive manufacturing” involves both additive and subtractive steps to arrive at a final part shape.
Explaining video for the process: