Effects of laser welding on the martensitic transformation of a shape-memory Ti-Ni alloy

Abstract

The objective of this study is to investigate the martensitic transformation behavior of a Ti-Ni alloy subjected to a laser welding process. Materials characterization techniques were used to analyze the influences of this welding procedure on the phase transformation behavior. This study can provide valuable insights for the improvement of Ti-Ni alloy welding processes used for technological applications, such as in the aerospace industry. In this study, samples were prepared under three conditions: thermal treatment at 400°C, thermal treatment at 500°C, and as-received. The characterization techniques used were: Optical Microscopy (OM), Differential Scanning Calorimetry (DSC), Electron Dispersion Spectroscopy (EDS), X-Ray Diffraction (XRD), and Vickers Microhardness (HV). The results allow for analysis of thermoelastic martensitic transformation and variations in the compositions of the alloy elements. The research, in general, aims to repurpose welding waste in Ti-Ni alloys for the production of mini sensors. The enthalpy was higher for the alloy treated at 500°C and welded. The research findings led to the observation of martensitic phase transformation in the laser-welded Ti-Ni alloy, which suggests that it can be used as a sensor/actuator.