Laser treatment of aluminum surface: Analysis of thermal stress field in the irradiated region

Laser surface treatment of aluminum is considered and the temperature as well as the stress fields developed in the laser irradiated region are predicted using the finite element method (FEM). The predictions are obtained for two laser pulses with different pulse lengths. In the simulations, the variable thermal properties of the substrate material are used. The experiment is conducted to treat the aluminum specimen surface with the laser beam. The laser output pulse intensity consists of repetitive pulses, which are used in the model study to examine the metallurgical changes in the irradiated region. SEM and XRD are carried out in this regard. It is found that the von-Mises stress reaches the maximum in the surface vicinity, particularly at the onset of cooling cycle starts. The von-Mises stress attains values less than the critical values for the crack formation, which is particularly true after the end of the cooling cycle. The residual stress formed in the surface region is in the order of a few MPa.