ABSTRACT

This study presents an investigation on the effectiveness, automation characteristics, and mechanics of joints between different material types namely glass fiber reinforced plastics (GFRPs) and SS304 stainless steel using an industrial Nd: YAG continuous-wave laser welder and a 2-axis custom design jig. The custom design jig includes computer-controlled (CNC) step motors, which provide high accuracy position control of the selected laser patterns. Four different patterns (Linear Curve, Hilbert Curve, Triangle Weave, and Curlique Weave) are investigated under different process parameters (laser power, lap joint length, and traveling speed) to obtain more robust joints. The strength of the joint is examined by variance analysis and found that the laser power and the pattern are the most important factors. Tensile shear tests present that the best-resulted joint carried around 4000 N before fracture. Polymer vaporization resulted in sub-millimeter sized bubbles that are widely formed inside the molten zone of the GFRP specimen. Therefore, a strong joint between GFRP and SS304 stainless steel could be obtained by a direct laser joining process at low power, with load adaptable space-filling curve patterns and without needing surface pretreatment, sophisticated clamps or high clamping forces.

摘要

本研究使用工业 Nd:YAG 连续波激光焊机和 2 轴定制设计，对不同材料类型（即玻璃纤维增​​强塑料 (GFRP) 和 SS304 不锈钢）之间的接头的有效性、自动化特性和力学进行了调查夹具。定制设计夹具包括计算机控制 (CNC) 步进电机，可为所选激光图案提供高精度位置控制。在不同的工艺参数（激光功率、搭接接头长度和行进速度）下研究了四种不同的图案（线性曲线、希尔伯特曲线、三角形编织和卷曲编织），以获得更坚固的接头。通过方差分析检查接头的强度，发现激光功率和图案是最重要的因素。拉伸剪切试验表明，结果最好的接头在断裂前承受了大约 4000 N。聚合物蒸发导致亚毫米大小的气泡在 GFRP 试样的熔融区域内广泛形成。因此，GFRP 和 SS304 不锈钢之间的牢固接头可以通过低功率的直接激光连接工艺获得，具有可适应负载的空间填充曲线图案，无需表面预处理、复杂的夹具或高夹紧力。