A new way to obtain NiTi SMA superelastic meshes: investment casting followed by hot rolling

Abstract

In this work, NiTi superelastic meshes are manufactured through plasma melting followed by an injection into a mesh ceramic coating mold obtained by the lost wax technique. This is the first time such a manufacturing sequence is reported for NiTi SMA. Focus is given to the feasibility and efficiency of the manufacturing process. The as-cast NiTi meshes were afterward heat-treated and hot-rolled for thickness reduction and to increase malleability. After manufacturing, the meshes’ thermomechanical properties were characterized. Differential scanning calorimetry showed that at room temperature the NiTi meshes can either be used as thermal actuators (using the shape memory effect) or as superelastic devices, depending on whether heating or cooling is performed prior to the application. This behavior leaves great potential for applications in engineering systems and biomedical uses. The superelastic behavior of the NiTi meshes was characterized through tensile tests at room temperature, showing very good cycling stability and strain recovering up to 4%. In the future, microstructural and biocompatibility investigations of the product will be evaluated to optimize the manufacturing process.