微小下压量下2024/7075异种铝合金FSLW接头的显微组织及力学性能研究

Microstructure and Mechanical Properties of 2024 and 7075 Dissimilar Aluminum Alloy FSLW Joints under Slight Plunge Depth

微研究了小下压量下2024/7075异种铝合金搅拌摩擦搭接焊接头的横截面形貌及力学性能。结果表明,使用小下压量可以有效减小钩状缺陷的高度,提高有效板厚值。拉剪试验时,裂纹由钩状缺陷尖端沿着焊核区扩展至另一端搭接界面处,导致接头断裂;接头拉剪强度达到76.78 MPa。

The cross sectional morphology and mechanical properties of friction stir lap welding （FSLW）joints of 2024 and 7075 dissimilar aluminum alloy was studied by using slight plunge depth. The results show that the heights of the hook defect can be effectively reduced and the effective sheet thickness can be improved by using slight plunge depth. During the tensile shear test, the crack propagates along the weld nugget zone from the tip of hook defect to the lap interface at the other end, and leads to fracture. The tensile shear strength of the joint reaches 76.78 MPa.