Abstract: In order to realize the high-quality solid-phase additive manufacturing of aluminum-copper layer-metal composites and overcome the limitations of the output power of the existing ultrasonic power devices, a high-power ultrasonic additive manufacturing equipment and method with an auxiliary thermal field is proposed. It is analyzed that the effect of thermal field on the microstructure and properties of aluminum-copper interface. The multi-laminated ultrasonic consolidation experiments are performed at different auxiliary temperatures using T2 copper foil and 1060 aluminum foil. The Al/Cu and Cu/Al interface forms are studied, and the peel test with fracture morphology analysis show that the Cu/Al interface form has a higher peel strength. It is analyzed that the Al-Cu interface microstructure characteristics at different heating temperatures using SEM and EDS methods. The metallographic and mechanical performance test results show that the mechanical strength of the Al/Cu interface increases with the rise of the auxiliary heating temperature, and the Al-Cu interface can form an effective solid-phase connector under the ultrasonic action at the heating temperature of 100℃. The maximum mechanical strength reaches 26.23 N/mm, and the width of the element diffusion layer at the interface between Al/Cu and Cu/Al is up to 4-6 μm. The interface fracture presents the morphology of the torn prism with quasi-cleavage fracture. The processing quality and efficiency by the means of auxiliary heat field during the process of ultrasonic additive manufacturing Al-Cu layer-metal composites.

Key words: Al/Cu layer-metal composites, heating temperature, host-assisted, mechanical properties, ultrasonic additive manufacturing