摘要本文针对中大直径铝合金螺柱难以采用螺柱焊的技术问题,以直径16mm螺柱为研究对象进行了铝合金螺柱焊接工艺试验研究。提出了TIG-拉弧复合热源技术。并结合接头的力学性能、微观形态对各工艺参数进行了综合的分析和评价。68170
铝合金电弧螺柱焊仅使用陶瓷环保护时接头内部会生成大量的缺陷,采用惰性气体保护后获得较好接头的质量。焊接电流过大将破坏惰性气体的保护效果。
TIG-拉弧复合热源中的TIG电弧可去除铝板表面的氧化膜。TIG电弧同时起到预热的作用,可降低焊接电流,降低热裂纹生成的机率。由于铝板的预热,焊接电流过大时易使飞溅增大,导致出现缺陷的机率增大。
铝合金螺柱预浸镀Zn-Ni能够有效地防止铝氧化膜的生成,并且镀层金属不会为焊缝带来夹杂缺陷。螺柱经浸镀处理后,在较宽的电流范围内都能得到性能稳定的接头。
毕业论文关键词:铝合金 螺柱焊 复合热源 浸镀
Title stud welding of aluminum alloy by CHS
Abstract
The method of stud welding of aluminum alloy has been studied in this dissertation. It was proved initially that inert gas protection is needed in the process of aluminum stud welding. The mechanical properties, micro configuration of the welding joint are studied to estimate the method and the effect of the technical parameters.
A lot of falty fusion, gas hole and oxygenation appeared in the joint with ceramic ring only. The intension of the joint was enhanced when inert gas protection was used. When the welding current got too large, it would undermine the protection effect was reduced by the splash.
The oxygenation on the surface of the Al board was wiped off by the TIG arc of the CHS effectively. The welding current decreased as the Al board was preheated; also, welding defects were more likely to appear as the welding current got larger and the protection effect was reduced by the splash.
The oxidation of the Al board would cease after SP treatment, neither would the soak plate coating bring dedect into the welding joint. When welding current rose to a certain level, the affection of welding current to the quality of the joint was weaken. Fine weld organizations and high intension of the welding line would be gained under appropriate welding current.
Key word: Aluminum alloy, Stud welding
目录
1绪论 1
1.1 课题研究背景及选题意义 1
1.2 铝合金 1
1.2.1 铝合金焊接性 1
1.2.2 铝合金在汽车上的运用 1
1.3 铝合金焊接技术 1
1.3.1铝合金的激光焊 1
1.3.2 铝合金的激光-电弧复合焊 2
1.3.3 铝合金的双光束激光焊 2
1.3.4 铝合金的摩擦搅拌焊(FSW ) 3
1.4 螺柱焊 3
1.5 螺柱焊现状 3
1.6 TIG电弧辅助焊接原理 4
1.7 拉弧螺柱焊 5
2 试验材料及设备 6
2.1 试验材料 6
2.1.1 材料尺寸及处理 6
2.1.2 瓷套 7
2.2 焊接试验设备 8
2.2.1 螺柱焊机