Mechanical Properties of NiTi Shape Memory Alloys Welded Joints: A Comparative Study between the GTAW, PAW and LBW Processes

Abstract

In this study mechanical behavior of Nickel-Titanium (NiTi) shape memory alloy (SMA) thin sheets welded joints obtained by Gas Tungsten Arc Welding (GTAW), Plasma Arc Welding (PAW) and Laser Beam Welding (LBW) processes were evaluated. The effects on mechanical properties of welding parameters and post-weld heat treatment were verified by means of tensile tests and hardness measurements. NiTi welded joints achieved ultimate tensile strength of 760MPa and 23% strain in GTAW welding process, 550 MPa and 11% strain in LBW, 500 MPa and 8% strain in PAW welding process. These results can be considered compatible and even superior to those verified in the literature, mainly for the GTAW and PAW processes.