【摘要】 为了解决铝合金对接接头光纤激光焊的质量问题,采用热弹塑性有限元技术模拟焊接过程中的试样温度和应力变化,研究试样瞬态温度场和应力场变化规律及其分布特征,探讨激光功率和焊接速度对焊接质量的影响规律。实验采用的激光焊接系统,可实现快速预热并在充满氮气的密封腔中完成焊接过程。实验选取数值模拟确定的激光功率和焊接速度值,焊接完成2 mm厚6061-T6铝合金板对接接头。光纤激光焊接头的上下表面焊缝形貌平整连续,拉伸疲劳断口位于焊缝一侧的热影响区(HAZ)。模拟结果为光纤激光焊的机理研究和优化光纤激光焊接工艺提供了支持。更多还原

【Abstract】 To improve the quality of the aluminum alloy butt joint in the process of optical fiber laser welding, thermo-elastic-plastic finite element technology is applied to simulate the temperature and residual stress in the process of welding, to study the laws of transient temperature field and residual stress field changes and distribution,and to probe on the influence of laser power and welding speed on welding quality. The laser welding system can automatically preheat and weld in a sealed cavity filled with nitrogen. In the experiment,the welding is completed on 2 mm-thick 6061-T6 aluminum alloy plate butt joints with laser power and welding speed determined by the simulation. The surface of the joints is smooth and continuous. The tensile fatigue fractures are located in the heat affected zone( HAZ) of the welded joints. The results will provide support for the mechanism study and optimization of optical fiber laser welding process.更多还原