研究了激光透射焊接聚碳酸酯工艺, 从断口形貌及材料吸光率两个方面探究了焊接质量与表面粗糙度的关系。基于Weierstrass-Mandelbrot函数与实测点数据, 构建了三维真实表面模型, 进行了单板焊接温度场的数值模拟。实验结果表明, 随着试件表面粗糙度的增加, 焊接质量下降。模拟结果表明, 粗糙表面比光滑表面先到达最高温度, 而光滑表面的最高温度高于粗糙表面的; 随着焊接速率的增大, 焊接温度整体减小, 且具有不同粗糙度的表面的温度变化曲线逐渐重合。

The process of laser transmission welding of polycarbonate is studied. The relationship between welding quality and surface roughness is investigated from the perspectives of fracture morphology and material absorptivity. Based on the Weierstrass-Mandelbrot function and measured points data, the three-dimensional real surface model is built and the temperature field numerical simulation of single-board welding is carried out. Experimental results show that, with the increase of the specimen surface roughness, the welding quality deteriorates. Simulation results show that the rough surface reaches peak temperature faster than the smooth surface, while the peak temperature of the smooth surface is higher than that of the rough surface. With the increase of the welding rate, the welding temperature appears an overall decline, and the temperature variation curves of surfaces with different roughness overlap gradually.