铝/钢电弧辅助激光对接熔钎焊铺展特性

Spreading characteristics of arc-assisted laser welding filler metals for welding-brazing butt joint between aluminum alloy and galvanized steel

关键词:  铺展宽度  铝/钢  电弧辅助激光  熔钎焊

Key words:  spreading width  aluminum steel  arc-assisted laser  welding-brazing

摘要:

采用小功率TIG电弧辅助激光热源进行5A06铝合金和热镀锌ST04Z钢的预置粉末对接熔钎焊工艺试验,通过SEM,Photoshop来研究预留间隙、背面填涂钎剂、激光热输入、辅助电弧电流、热源中心间距、填加焊丝对熔钎焊接头铺展宽度的影响. 结果表明,预留小于0.5 mm的间隙与背面填涂钎剂均可增大铺展宽度;在未焊穿的前提下,随激光热输入和辅助电弧电流的增加,铺展宽度增大;随热源中心间距的增大,铺展宽度先增加后减小. 焊接熔池中填加Al-Si焊丝较未填加焊丝的铺展性更好,获得连续、美观的焊缝表面形貌.

Abstract:

Butt welding-brazing joint between 5A06 aluminum alloy and ST04Z steel sheets was obtained by low power arc-assisted laser welding with preplaced filler powder. The influence of pre-welding gap, filling brazing flux, laser heat input, assistant arc current, heat source center distance and adding welding wire on spreading characteristics of the filler metal was studied by using SEM, Photoshop. The results show that the pre-welding gap less than 0.5 mm and the filling brazing flux on the welds' back were favorable. When the workpiece was not burn through, the weld spreading width was increased with the increase of the laser heat input and assistant arc current. With the increase of the distance to the heat source center, the weld spreading width first increaseed then decreased. Adding wire welding in the molten pool offers better spreadability, continuous and sound weld appearance can be obtained than the condition without wire addition.