Molten Depth Modeling of Laser Transmission Welding Based on Temperature Distribution of Moving Point Heat Source

Abstract

Laser transmission welding (LTW) is a new and efficient technology. During LTW of polymers, the size and morphology of the weld have great influence on the welding quality. In order to better evaluate the welding quality and optimize process parameters, many researches on the morphology and mathematical analytical model of the molten pool have been conducted. This study attempts to build an analytical model for calculating the depth of the molten pool (molten depth), based on the temperature field distribution theory of the moving point heat source acting on the semi-infinite body. The influence of the welding power and welding speed on the molten depth is studied emphatically. The mathematical analytical model is solved through MATLAB mathematical software. Subsequently, the test experiment about LTW of PA66 is conducted to validate the model. During the test experiment, the upper layer contains 30 wt. % glass fibers (GF) and the bottom layer contains 30 wt. % carbon fiber (CF). The result shows that the mathematical analytical model can well predict the trend of the molten depth. However, the error exists indeed. The detailed analysis about the error is also made in this article.