SMART STRUCTURE INTEGRATION THROUGH ULTRASONIC ADDITIVE MANUFACTURING

Ultrasonic additive manufacturing (UAM), a form of 3D printing based on ultrasonic metal welding, allows for room-temperature fabrication of adaptive structures with seamlessly embedded sensors and actuators. UAM combines solid-state welding of metallic foils, automated additive foil layering, and CNC machining. The most recent UAM systems utilize 9 kW of ultrasonic power for improved build strength and quality over low power systems, leading to previously unfeasible smart structures. Current UAM efforts in this area are focused on embedding smart materials, fiber optics, and cooling channels into metallic matrices. Since UAM process temperatures do not exceed one half of the melting temperature of the matrix, various alloys such as NiTi and FeGa, and polymers such as PVDF, have been successfully embedded without degradation of the smart material or the matrix. This paper aims to demonstrate the benefits of UAM, with particular emphasis on smart components for vehicle design. Example concepts include stiffness-tunable structures, thermally invariant composites, and materials with embedded cooling channels.