Design, simulation, and experimental validation of a longitudinal ultrasonic transducer for micro deep drawing of aluminium-copper bimetallic foil

Abstract This study presents the design, simulation, and experimental validation of a longitudinal ultrasonic transducer for micro deep drawing (MDD) of aluminium (Al)–copper (Cu) bimetallic foils, and demonstrates its effectiveness in improving forming behaviour under diffusion-sensitive conditions. The transducer introduces controlled ultrasonic vibration into the MDD process to influence deformation behaviour and tool–workpiece interaction, while ensuring stable and controlled vibration transmission suitable for microscale forming conditions. Finite element analysis (FEA) using ABAQUS was used for the design and analysis of the developed transducer. Modal analysis identified the longitudinal resonance mode, while harmonic analysis was used to assess the vibration amplitude under resonance and off-resonance excitation. An off-resonance operating frequency of 35 kHz was selected for the intended application. The transducer was subsequently integrated into a purpose-built MDD setup and tested using Al–Cu bimetallic foils subjected to two annealing conditions: A300 (300 $$^\circ$$ C, 30 min) and A400 (400 $$^\circ$$ C, 30 min). Under identical tooling geometry and forming conditions, ultrasonic-assisted deep drawing (UADD) reduced the peak forming load by 33.3% for the A300 condition, while improving thickness uniformity, geometric stability, and surface quality of the drawn cups. For the A400 condition, where diffusion-driven growth of the intermetallic layer led to premature failure under conventional deep drawing (CDD), UADD enabled successful cup formation. These results demonstrate that the developed ultrasonic transducer enables effective ultrasonic-assisted MDD, allowing stable forming of diffusion-sensitive Al–Cu bimetallic foils under conditions where conventional processing is limited by interfacial effects.