Study on the actuating performance of NiTi/Si composite film

On the basis of considering the material nonlinearity of shape memory alloys, the mechanical model of the shape memory alloy composite film based on Si substrate is established by the method of mechanics of materials to study the coupled action between the shape memory alloy and Si substrate under thermal loads. The actuating performances of the SMA composite film are simulated and discussed for one whole thermal loading cycle, which verifies that large actuating forces and displacements can be produced in the narrow temperature range due to the phase transformations of shape memory alloys. It is also found that the maximum deflection of the composite film decreases with the increasing of the thickness ratio of the Si substrate to the shape memory alloy film. And the mechanical model established in this paper can describe and predict the actuating performances of the SMA composite film much more accurately when the thickness ratios are larger than five.