In-Situ Synthesis and Micro-Structural Characterization of Shape Memory Alloy-Nitinol by Laser Direct Deposition

Nitinol has unique Ni-Ti shape-memory and super-elastic properties along with excellent bio-mechanical compatibility and corrosion resistance.  However, it is very difficult to process this material and fabricate complex geometries from it. Nitinol properties are highly sensitive to the processing history used to fabricate the final component, and due to its poor machinability machining of Nitinol by conventional techniques is very difficult.   The goal of our work is to synthesize Nitinol in-situ using the laser direct deposition, directly from the elemental Nickel and Titanium powder, which will be more cost effective than using pre-alloyed Nitinol powder. Besides, this process would allow us to fabricate near net shaped complex geometries without the need of building moulds, tools or fixtures and hence making the process rapid.  Synthesize material is characterized using Scanning electron microscopy, Energy Dispersive Spectroscopy (EDS) and X-ray Diffraction.  Differential Scanning Calorimeter is used to determine the characteristic transformation temperature of Nitinol.