铝合金增材制造技术研究进展

电弧增材制造成形普遍存在结构件的形貌误差较大和精度控制难的问题，针对摆动钨极惰性气体保护焊（Weaving-gas tungsten arc welding, W-GTAW）热源铝合金增材制造过程，研究了不同摆动角度及摆动左右停止时间条件下增材制造薄壁的尺寸和成形形貌特点。对比常规GTAW电弧增材制造，W-GTAW薄壁成形件可以获得更小的基板熔透量，并且摆动速度和摆动左右停止时间越小，薄壁高度越高，当摆动速度为3.0 × 10⁻² rad/s、摆动左右停止时间为0.15 s时，薄壁熔覆高度为15.91 mm，仅次于常规GTAW薄壁成形件；对于薄壁壁厚，在电弧摆动左右停止时间为0.25 s条件下的W-GTAW成形件壁厚为13.83 mm，相较于常规GTAW壁厚增加了2.67 mm，并且此条件下基板两端翘起角度仅为0.2°；对比常规GTAW增材制造技术，W-GTAW得到了最大精度为0.92的薄壁，而在试验条件下，适当增大摆动角度和摆动左右停止时间，薄壁尺寸精度可以得到进一步提升。

Effect of auxiliary TIG arc on formation and microstructures of aluminum alloy/ stainless steel joints made by MIG welding-brazing process

Wire and arc additive manufacturing generally has problems of larger morphology error of structural parts and difficult precision control. For additive manufacturing process of aluminum alloys with weaving-gas tungsten arc welding (W-GTAW) heat source, size and morphology characteristics of additive manufactured thin walls were studied under different weaving angles and weaving left and right stop times. Compared with conventional GTAW arc additive manufacturing, W-GTAW thin-walled forming parts could obtain a smaller penetration of substrate, and the smaller weaving speed and weaving left and right stop time were, the higher thin-wall height was. When weaving speed was 3.0 × 10⁻² rad/s and weaving left and right stop time was 0.15 s, cladding height of thin-walls was 15.91 mm, second only to conventional GTAW thin-walled forming parts. For thickness of thin walls, wall thickness of W-GTAW formed part was 13.83 mm under the condition that arc weaving left and right stop time was 0.25 s, which was 2.67 mm higher than that of conventional GTAW, and tilt angle at both ends of substrate was only 0.2° under this condition. Compared with conventional GTAW additive manufacturing technology, W-GTAW obtained a thin wall with a maximum accuracy of 0.92. Under experimental conditions, dimensional accuracy of thin walls could be further improved by appropriately increasing weaving angle and weaving left and right stop time.