基于回归分析的钛合金微电阻点焊焊接工艺优化

Research on process parameters optimization of small scale resistance spot welding via regression analysis

为了研究焊接工艺参数对钛合金微电阻点焊焊接质量的影响规律以及获得最优的焊接工艺参数,利用中心组合试验设计对0.4 mm厚的TC2钛合金进行焊接试验,对焊接试样进行准静态拉伸试验,获取了表征焊点质量优劣的熔核直径、拉伸力、拉伸位移和失效能量.利用灰熵法得到了每个焊接质量指标的权值,将其加权为焊接综合质量指标.采用逐步回归分析方法得到了焊接工艺参数(焊接电流、焊接时间以及电极压力)与焊接综合质量指标之间的回归方程.在此基础上分析了焊接工艺参数两两交互作用对焊接质量的影响规律,采用爬山优化算法得到了最优的焊接工艺参数.

Central composite experimental design was used for the thickness of 0. 4 mm TC2 titanium alloy in order to optimize the small scale spot welded joint quality. The welding current,electrode force and welding time were picked out as the process parameters and the nugget size,peak load,tensile shear displacement and failure energy were weighted into a welding quality comprehensive index based on entropy measurement method. The mathematical model between the welding quality comprehensive index and process parameters was obtained using regression analysis. The interaction effects of the welding parameters on welding quality were explored. The optimal combination of welding process parameters was achieved by using hill climbing method. The results of validation experiments showed that this study could effectively forecast and optimize the welding quality for the TC2 titanium alloy with the thickness of 0. 4 mm.