铝/黄铜异种金属TIG填丝熔钎焊工艺

TIG welding-brazing for Al/Cu dissimilar metals using filler material

采用TIG熔钎焊进行5052铝合金和H62黄铜搭接,选用Al-12%Si药芯焊丝作为填充材料,并对接头微观组织和力学性能进行分析.结果表明,Al-12%Si药芯焊丝在黄铜母材表面润湿性较差,较难获得优质的熔钎焊接头.焊缝中黄铜侧界面层附近过渡区内铝含量较高,与部分熔化和溶解的黄铜母材形成了尺寸较大的条状AlCu金属间化合物相,严重影响接头力学性能.黄铜母材侧界面层由两层不同的金属间化合物相组成,从焊缝到黄铜母材分别为Cu_9Al_4和CuZn.拉伸试验中,试样断裂于黄铜侧过渡区或界面层,断口呈现解理断裂的特征.

5052 aluminum alloy and H62 brass dissimilar metals were lap welded by TIG welding-brazing with Al-12% Si flux-cored wire as filler material.Microstructure and mechanical properties of the joint were studied.High-quality welded-brazed joint is difficult to be obtained due to the poor wettability of molten Al-12 Si filler material on the surface of brass.Larger size strips of AlC u IMCs are formed in the transition zone at brass side due to the high Al content in the filler material and which reacted with the partially melted and dissolved brass base metal.The formation of Cu_9Al_4 IMC strips severely weak the mechanical properties of joint.The interface layer at brass side consists of two kinds of IMCs layers,which are Cu_9Al_4 and CuZ n from the weld to the brass base metal,respectively.Tensile test indicated that the joint fractures at the transition zone or interface layer of the brass side with cleavage fracture surface.