Laser welding of a NiTi alloy: Mechanical and shape memory behaviour

The present paper reports the effect of Nd:YAG laser welding on the mechanical and functional properties of Ni–51 at.% Ti alloy. The specimens were prepared from thin sheets and tested in martensitic conditions. The mechanical and shape memory effects of both welded and unwelded material (reference) were measured using standard tensile tests and thermo-mechanical cycles. Differential scanning calorimeter investigations were carried out to determine the phase transformation temperatures. Micro-hardness tests and microscopic investigations were performed in order to evaluate the extension of the heat affected zone and the melting zone. Finally, a systematic comparison of the results between welded and reference specimens was carried out.