Investigation on laser assisted post processing of wire arc additive manufacturing of NiTi shape memory alloys

Abstract

Additive manufacturing (AM) the process of joining materials to make parts or objects from 3D model data, basically layer over layer deposition, as to prevent to subtractive manufacturing technology. In my work wire, arc additive manufacturing (WAAM) technique is used for the fabrication of the metal parts as the workpiece, that is based on the principle of the metal inert gas (MIG) welding. Shape memory alloys (SMA's) is the alloys, which exhibit two unique properties such as pseudo-elasticity and the shape memory effect (SME). SMA’s alloyed metal that can sustain a large amount of deformation, through heating it will return to their original shape or heating above the austenite temperature. SMA’s have applications in robotics and automotive, aerospace and biomedical industries. This paper shows the experiments performed on WAAM fabricated NiTi bulk structure which was cut through the wire EDM and then after first performed the laser diffusion over copper coated NiTi and second the laser annealing of the NiTi thin strip sample. The investigation over the WAAM fabricated NiTi bulk structure has been done. After this characterization have been done by using a scanning electron microscope, optical microscope, micro-hardness, x-ray diffraction and composition analysis by using energy dispersive x-ray spectroscopy and phase transformation by using differential scanning calorimeter. And for shape memory effect by using hot plate actuation.