Abstract
Adhesive bonding offers a low-temperature route for integrating Nickel–Titanium (NiTi) with Aluminium (Al) without high-temperature interfacial reactions, but the role of laminate architecture in damping remains insufficiently quantified. Here, two NiTi–Al laminates were fabricated from 0.25 mm sheets using a flexible nitrile-rubber contact adhesive: a NiTi–Al bilayer (NA) and a NiTi–Al–NiTi sandwich (NAN). Free-vibration cantilever tests with laser displacement sensing yielded first-mode damping ratios and natural frequencies by logarithmic decrement; monolithic Al and NiTi beams of nominally matched metal-stack thickness were tested as references. NA showed 12% and 16% above 0.50 mm Al and NiTi, respectively. NAN showed 72% above NA, with its first natural frequency between the 0.75 mm monolithic references. COMSOL eigenfrequency predictions agreed with experiment within about 8%. An analytical Ross-Kerwin-Ungar (RKU) model treating the adhesive as a viscoelastic shear layer was calibrated against the excess damping above the monolithic baseline. The model identifies adhesive shear as one contributor to dissipation but does not reproduce the measured excess-damping ratio between the two architectures, which indicates additional mechanisms. The results establish adhesive bonding as a viable route to lightweight NiTi–Al laminate structures with raised damping and identify the symmetric sandwich architecture as the main lever.