立上电弧增材制造板件的成形精度影响与优化

Effect and Optimization of Forming Accuracy in Wire Arc Additive Manufacturing of Sheet Metal at Vertical Position

目的针对悬臂结构立焊位置成形质量差的问题,本研究旨在探究电弧增材制造工艺参数对悬臂结构多道搭接质量及组织的影响规律,以实现悬臂结构工艺参数的预测与优化,从而提高多道搭接焊道表面质量与内部组织性能。方法采用响应面Box-Behnken方法,分析焊接电流、焊接电压和偏移量对焊接接头成形与性能的影响规律,建立了工艺参数与焊接接头响应指标的数学模型。结果试验结果表明,表面平整度与焊接电压成正比,与搭接率成反比;偏移量的增加先使总高减小,然后有所增加,而焊接电流与总高成正比;偏心率与焊接电流成正比,与搭接率成反比。以平整度大、总高大、偏心率接近于1为优化目标,最佳工艺参数为电流85.4A,电压22V,偏移量为3mm。与预测值相比较,实际值的平整度、总高和偏心率的误差率分别为0.48%、4.40%和1.89%。研究还探究了单道多层焊接接头组织性能与工艺参数的关系,发现了焊接热影响重合区组织细化的现象。结论研究结果验证了所构建数学模型的可靠性,对改善高难度悬臂结构制造的形貌以及提高成形质量具有重要的指导意义。

Aiming at the problem of poor forming quality of the cantilever microstructure in the vertical welding position,the work aims to explore the effect of arc additive manufacturing process parameters on the quality and microstructure of multi-pass lap of the cantilever microstructure,and achieve the prediction and optimization of the cantilever microstructure process parameters,thus optimizing and improving the surface quality and internal microstructure properties of multi-pass lap welds.Based on the response surface Box‒Behnken method,the effect of welding current,welding voltage,and offset on the formation and performance of welded joints was analyzed, and a mathematical model of process parameters and welded joint response indicators was constructed. The test results showed that the surface flatness was directly proportional to the welding voltage and inversely proportional to the lap rate. The increase in offset caused the total height to firstly decrease and then in-crease, and the welding current was proportional to the total height. The eccentricity was directly proportional to the current and inversely proportional to the lap rate. Taking large flatness, total height, and eccentricity close to 1 as the optimization goals, the optimal process parameters were current of 85.4 A, voltage of 22 V, and offset of 3 mm. Through the comparison between the predicted values and the actual values, the error rates of flatness, total height, and eccentricity were 0.48%, 4.40%, and 1.89% respectively. The relationship between the microstructure properties and process parameters of single-pass multi-layer welded joints was also explored, and the phenomenon of microstructure refinement in the lap area affected by welding heat was ob-tained. The research results show the reliability of the constructed mathematical model, which has important guiding signifi-cance for improving the morphology and forming quality of difficult cantilever manufacturing.