The effect of interface topography for Ultrasonic Consolidation of aluminium

Ultrasonic Consolidation (UC) is an additive manufacturing technology which is based on the sequential solid-state ultrasonic welding of metal foils. UC presents a rapid and adaptive alternative process, to other metal-matrix embedding technologies, for 'smart' metal composite material production. A challenge that exists however relates to optimising, for bond density and plastic flow, the interlaminar textures themselves that serve as the contact surfaces between the foils. UC employs a sonotrode connected to a transducer to exude ultrasonic energy into the metal foil being sequentially deposited. This sonotrode to metal contact imparts a noteworthy topology to the processed metals surface that in turn becomes the crucial substrate topology of the subsequent layers deposition. This work investigated UC processed Al 3003 samples to ascertain the effect of this imparted topology on subsequent layer deposition. Surface and interlaminar topology profiles were characterised using interferometry, electron and light microscopy. The physical effect of the topology profiles were quantified via the use of peel testing. The imparted topology profile was found to be of fundamental significance to the mechanical performance and bond density achieved within the bulk laminate during UC. The UC process parameters and sonotrode topology performed a key role in modifying this topology profile. The concept of using a specifically textured sonotrode to attain desired future smart material performance via UC is proposed by the authors.