Finite element simulation and experimental study about laser micro-joining between biopolymer and metal

In order to understand the laser micro-joining mechanism better, based on the ANSYS, finite element simulation software, the Gaussian heat source model was adopted to simulate the dynamic temperature filed in the process of welding polyethylene terephthalate (PET) and biomedical Ti. The transition highest peak temperature variation during the process of welding was recorded with a thermal infrared imager and the actual welding seam width was measured with a digital microscope in super depth of field. The simulation results are conforming to the experimental results. Simulation result suggests that the isotherm is as an ellipse. Meanwhile, there is intensive isotherm and larger temperature gradient in the front of the spot center, on the contrary, sparser isotherm and smaller temperature gradient at the back of the spot center, which verifies the applicability of the model established by moving heat source during the laser welding based on PET/Ti sheets applying to the temperature field simulation.