The paper analyzes the behavior of the deformation characteristics of welded joints made of TiNi alloy with a shape memory effect. Comparison of the level of tensile strength of welded samples made by the TIG method in an Ar and He atmosphere was carried out using a Instron 5985 universal machine. The study of the material structure in the weld zone and the heat-affected zone was carried out on longitudinal sections using a JSM-6490LV electron microscope. To estimate the mechanical parameters PMT-3 microhardness tester was used. The calorimetric parameters of the welded samples were obtained using a differential scanning calorimeters METTLER TOLEDO 822e and TA Instruments Q20. To analyze the gradient properties at the weld zone and the heat-affected zone, the temperature fields were calculated using the thermal conductivity equation included in the model of the residual stress mechanism.