母材相对位置对搅拌摩擦焊接铝/铜异种金属接头性能的影响

Effect of base metal relative positions on properties of Al/Cu FSW joint

关键词:  搅拌摩擦焊  铝/铜异种金属  工艺优化  母材相对位置

Key words:  friction stir welding  Al /Cu dissimilar metals  procedure optimization  base metal relative location

摘要:

铝、铜两种金属性能差异较大,用常规焊接方法难以实现连接,极大地限制了铝/铜复合接头的质量和应用范围.利用搅拌摩擦焊接技术成功焊接了防锈铝合金/紫铜异种金属的对接接头,通过焊缝接头表面宏观形貌观察、接头横断面组织分析及接头的抗拉强度分析母材相对位置对铝/铜搅拌摩擦焊接头性能的影响.结果表明,搅拌针相对配合面存在偏移的情况下,母材铜板放置在返回侧时,焊缝接头的成形性好;接头的组织形貌出现明显的"洋葱"环状;接头的最大抗拉强度达到225 MPa,可达母材紫铜抗拉强度的76.3%;接头断裂多发生在前进侧热影响区或接头的焊核区域.

Abstract:

The dissimilar materials (5A06 aluminum alloy/copper T2) were difficultly welded by conventional fusion welding because of the enormous difference of their thermo-physical performances. The butt joint of dissimilar metals was welded with friction stir welding method. This paper mainly studied on the relative location effect of the base metal on the forming of the FSW joint by analyzing the mechanical properties, and the macro-morphology of weld surface and macrostructures of transverse section of welds. The results indicated that a good Al/Cu FSW joint can be achieved with the proper base metal relative position. When the copper plate was on the retreating side (RS) and the offset of the pin from weld centerline existed, the formation of the welded joints were pretty good, the 'onion' ring structure in the stir zone could be observed clearly and the tensile strength of joint could reach 225 MPa, which was 76.3% of copper T2. Most of the welded joints fractured in the heat affected zone (HAZ) of advancing side (AS) or the nugget zone (NZ).