2060合金FSW接头微观组织与力学性能

Microstructures and mechanical properties of 2060 alloy FSW joint

利用金相显微镜、显微硬度测试、拉伸性能测试、扫描电镜、透射电镜等手段对2060-T8合金搅拌摩擦焊(FSW)接头的微观组织和力学性能进行研究。结果表明:焊接头的抗拉强度为441 MPa,屈服强度为320 MPa,伸长率为6.9%,但焊接强度系数达到82.9%;经过搅拌摩擦焊,母材的织构类型以及强度发生了变化,由黄铜织构变为高斯织构且强度变弱;热影响区T1相(Al2CuLi)部分发生了溶解,析出了δ′相(Al3Li),热机影响区内T1相大部分溶解,S′相(Al2CuMg)发生了粗化,焊核区析出相全部溶解。

The 2060-T8 FSW joint was studied by means of metallographic microscope, microhardness test, tensile test, SEM and TEM on the microstructure and mechanical properties. The results show that the tensile strength is 441 MPa, the yield strength is 320 MPa and the elongation is 6.9%. But the joint strength coefficient is 82.9%. The texture type and intensity of base material change after FSW, and the texture type changes from Bass texture to Gauss texture and the intensity decreases. T1 precipitates partly dissolve and δ′ precipitates are found in heat affected zone （HAZ）. More T1 precipitates dissolve and S′ precipitates are coarsen in thermo mechanically affected zone （TMAZ）. The precipitates absolutely dissolve in nugget zone （NZ）.