FE simulation and experimental verification of tube cladding process using spherical tipped punch

Bimetallic tubes are increasingly utilized in heat exchangers, petrochemical transport, and renewable-energy systems due to their ability to combine structural strength with cost efficiency. This study introduces a novel press-based tube cladding process using a spherical-tipped punch to achieve localized plastic deformation for bonding AA6060 aluminum inner tubes with SS304 stainless-steel outer tubes. A comprehensive experimental program supported by validated FE simulations (≤5 % deviation) was conducted to investigate the influence of axial feed rate and friction mode on forming load, interfacial bonding quality, hardness, and surface integrity. Results showed that the process achieved complete bonding at a feed rate of 0.33 mm/min, with a significantly reduced forming load of 60.30 kN compared to the 80–100 kN range reported in conventional cladding studies. The maximum interfacial shear strength reached 2683 kgf, accompanied by a minimum surface roughness of 0.44 µm, indicating excellent metallurgical adhesion and smooth surface finish. Conversely, higher feed rates of 2 and 5 mm/min resulted in partial bonding, increased roughness, and premature flange failure due to accelerated material accumulation. The FE predictions confirmed that Coulomb friction (μ = 0.25) provided the most accurate representation of experimental force evolution. The proposed forming strategy demonstrates a substantial improvement in energy efficiency, bond quality, and process controllability compared to rotary swaging, spin-bonding, and explosive cladding methods, highlighting its potential as a scalable and industrially viable technique for manufacturing high-performance SS/Al bimetallic tubes.