Thermo-mechanical finite element analysis of ultrasonic powder consolidation process

Ultrasonic welding is a solid-state joining process which uses ultrasonic vibration to join materials at relatively low temperatures. Ultrasonic powder consolidation is a derivative of the ultrasonic additive process which consolidates powder material into a dense solid block without melting. During ultrasonic powder consolidation process, metal powder under a compressive load is subjected to transverse ultrasonic vibrations resulting in a fully-dense consolidated product. While ultrasonic powder consolidation process is employed in a wide variety of manufacturing processes, bonding mechanism of powder particles during the consolidation process is not clearly understood. This study uses a coupled thermo-mechanical finite element analysis technique to understand the underlying bonding mechanism involved in ultrasonic powder consolidation process. The study also investigates the effect of critical process parameters including vibrational amplitude and base temperature on the stress, strain, and particle temperature distribution during this process. Based on the results of the simulation, a possible theory on the bonding mechanism involved in ultrasonic powder consolidation process is proposed. The outcomes of this study can be used to further the industrial applications of ultrasonic powder consolidation process as well as other ultrasonic welding based processes.