Ultrasonic Consolidation (UC) is a recently developed direct metal solid freeform fabrication process. While the process has been well-demonstrated for part fabrication in Al alloy 3003, some of the potential strengths of the process have not been fully exploited. One of them is its flexibility with build materials and the other is its suitability for fabrication of parts in multi-materials with enhanced functional or mechanical properties. In the current work, UC was used to investigate ultrasonic bonding between Cu-Al, Cu-Cu, and Al-Cu in order to assess the possibility of fabricating multi-material parts out of Al and Cu. Microstructural studies were conducted to evaluate interfacial characteristics between the three material combinations. The results showed that satisfactory bonding can be achieved in all cases through careful selection of process parameters. The work shows that Cu is quite amenable for part fabrication using UC. Also, it shows that UC is capable of fabricating quality multi-material parts out of Al and Cu. © 2008 Taylor & Francis Group.