A semi-analytical solution for 2-D axisymmetric modeling of repetitive pulse laser heating with body absorption

摘要

In the forthcoming paper (Chen et al., 2017), we presented an analytical solution for two-dimensional (2-D) modeling of repetitive pulse laser heating with surface absorption using the method of separation of variables combining with Laplace transform. But in practice, it often confronts the body absorption for the laser heating. Unfortunately, the above method due to the surface absorption is no longer suitable to the body absorption. In this paper, a semi-analytical solution for 2-D axisymmetric modeling of repetitive pulse laser heating with body absorption is obtained using the integral transform method. The method is validated by comparing with the results of existing finite element method. Temperature distributions for different repetitive pulses heating Silicon are modeled, and some physical mechanisms of repetitive pulses heating are analyzed. Results show that: repetitive pulse laser heating has obvious temperature intermittent cumulation effect; in the thin layer of material surface vicinity, temperature rises due to absorption of irradiated energy dominates over the conduction energy transport from surface to vicinity, and as the depth increases, the absorption decreases, whereas the conduction enhances; the shape of radial distribution of temperature is similar to that of the radial distribution of laser intensity for both Gaussian and flat top laser.