Numerical and experimental investigation of thermal stress distribution in laser lap welding of Ti6Al4V and 2024 alloy plates.

This paper investigated the thermal stress distribution in laser welding of Ti6Al4V and 2024-T4 alloys using the coupled thermal–mechanical model based on the thermo-elastoplastic theory. The microstructure and hardness of the dissimilar joint were analyzed based on the simulated results. The asymmetry of temperature and stress distribution indicated that the great difference of material properties had significant effects on the uniformity of thermal stress distribution. The combination of experiment and simulation demonstrated that the growth of grains in heat-affected zone and fusion zone was closely related to the thermal cycle process. The good agreement between the simulated and experimental results verified the rationality of the combined heat source model of double ellipsoid and rotating Gaussian body. The coupled model and simulated results could offer the instructive information in laser welding for other dissimilar alloys. [ABSTRACT FROM AUTHOR]