Mechanical characterization of shape memory alloy thin films through membrane deflection experiments

This study investigates the feasibility of measuring the tensile properties of shape memory alloy (SMA) thin films using membrane deflection experiments (MDE) combined with finite element analysis (FEA). Uniaxial tensile tests and MDE on a 549nm-thick Ni53.7Ti46.3 film exhibited close agreement in the resulting stress–strain curves. It was demonstrated that reducing the bending stiffness of membranes improves measurement accuracy. FEA further revealed that the material properties both before and after martensitic transformation can be measured with reasonable accuracy. In addition, residual stresses were also reliably captured, and the influence of martensitic transformation on local stress distribution was systematically analyzed. Overall, these findings demonstrate that MDE provides a robust approach for evaluating the tensile properties of SMA thin films, and the method is anticipated to expedite the rapid mechanical characterization of alloy thin films in future studies.