Numerical simulation of defect influence on nanosecond laser manufacturing

It has been proved in various experiments that defects in the workpiece lead to laser damage threshold reduction. However, without the suitable numerical model, it is still difficult to comprehend the underlying physics of the defect effect during laser manufacturing via experiments. In order to solve the problem, we design a numerical model combining heat transfer, solid mechanics and electromagnetic field to study laser pulse irradiating on the defective workpiece, which not only is proved with high accuracy according to the coincided results respectively obtained via experiments and simulations, but also clearly demonstrates that the defect in workpiece induces significant local enhancement on the light intensity, temperature and thermal stress thus reduces laser damage threshold. Considering the accuracy and convenience of the proposed numerical model of laser pulse irradiating on the defective workpiece, it not only can be a useful tool to analyze the defect effect during laser manufacturing, but also provides a potential theoretical and numerical model for developing lower-power laser manufacturing such as reduced laser energy and power.