5052铝合金FSW接头组织和力学性能

采用搅拌摩擦焊焊接8 mm厚5052-O铝合金,并对焊接接头进行了显微组织观察和力学性能测试。结果表明:接头组织左右不对称,前进侧与母材分界线较明显,后退侧与母材分界线较模糊;焊接接头抗拉强度平均值为193.5 MPa,接头强度可达母材的99%,伸长率可达母材的84%;焊接接头正弯角和背弯角均可达到180°,弯曲性能良好;焊核区显微硬度约为72 HV,略高于母材,硬度最低点出现在前进侧熔合过渡区。

Microstructure and mechanical properties of 5052 aluminum alloy FSW joint

8 mm thick 5052-O aluminum alloy was welded by friction stir welding (FSW),and the microstructure of the welded joint was observed,meanwhile,the mechanical properties were tested.The results show that the microstructure of the welded joint is leftright asymmetry.The boundary of advancing side and base metal is obvious,but the boundary of retreating side and base metal is fuzzy.The average tensile strength of the welded joint can reach 193.5 MPa,the joint coefficient of strength can reach 99％ of base metal,and the elongation can reach 84％ of base metal.No cracking is found in the welded joint at the 180° face bending test and 180° back bending test.The microhardness of weld nugget zone is 72 HV,which is slightly higher than base metal.The minimum of the microhardness is in the advancing side fusion zone of transition.