Investigating the effect of printing VED and post-processing heat treatment on the SME of nitinol electromechanical actuators.

Shape memory alloy actuators are a low-shock alternative to the traditional pyrotechnic release devices employed in spacecraft and satellites. In this study, the effect of printing volumetric energy density and post-processing heat treatments on the response of electro-mechanical nitinol actuators was investigated. 50:50 Nitinol powder was used to print rectangular lattice structures for the purpose of actuators. The effect of VED and post-processing heat treatment on the response of these actuators was studied by varying the laser power and scanning velocity as well as the post-process heat treatment temperature. The printed parts were characterised by DSC, XRD, EDX and SEM to determine the transformation temperatures, changes in composition, and phases present. The performance of the printed parts as actuators was tested on an in-house built rig which measured the maximum displacement and the time taken to complete actuation. The results were used to determine the optimum parameters for actuator response.