This article presents the mechanical analysis of an emerging nonthermal Rapid Manufacturing technology for layered fabrication of metallic or multiple-material products, i.e. the Multi-material Ultrasonic Adhesion process, based on Ultrasonic Welding. Its laboratory implementation, automation and integration, and parameter optimization are described first. The mechanics of Ultrasonic Welding, the stress and strain field changes during one weld, and static and dynamic behavior of the weld material are then analyzed. The technical advantages of Ultrasonic Welding for the manufacturing industry include fabrication of dense, full-strength functional solid metal parts, multiple-material composites, and active parts with embedded intelligent components and electronic, mechatronic, optic and fluidic structures.