Development of an ultrasonic solid-state additive manufacturing system for continuous bonding of thermally challenging metallic foils and sheets

Abstract

This paper presents development and validation of ultrasonic solid-state additive manufacturing (USSAM) system for continuous bonding of multi-material laminates (MML) of foils and/or sheets of thermally challenging materials (having high thermal conductivity and/or diffusivity). The developed system integrates a novel horizontally rotating ultrasonic tool with the 3-axis computer numerically controlled worktable for continuous feeding of metallic foils or sheets under electro-pneumatically controlled compressive force to enable their good quality solid-state bonding without melting. The ultrasonic tool comprises of a piezoelectric transducer, booster, and sonotrode. Finite element simulations were used to ensure structural integrity of critical components under the applied loads thus confirming their safe operations. Functionality and performance of the developed system was validated by performing 27 full-factorial experiments by varying ultrasonic vibration amplitude, compressive force, and feed rate at 3 levels each and fabricating 27 MML of Al–Cu of 400 μm thickness. Analysis of variance and grey relational analysis identified optimum parametric combination of ultrasonic vibration amplitude, compressive force, and feed rate as 28 μm, 5000 N, and 0.38 m/s respectively. The corresponding MML yielded 60.82 N as maximum peel-off strength and 80.5% bonding efficiency. Its microstructural analysis revealed continuous and uniform interfacial bonding with minimal defects indicating high-quality metallurgical bonding. It is found that compressive force is the most influential parameter contributing 50% to the bonding strength. Developed USSAM system has potential to provide viable solutions to the thermally sensitive systems that require reliable and improved solid-state bonding such as embedded electronics, electromagnetic shielding, electric vehicles, solar panel, avionics. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2026.