异种铝合金搅拌摩擦焊工艺研究

Study on Friction Stir Welding of Dissimilar Aluminium Alloy

研究了7075/5083异种铝合金搅拌摩擦焊接头形貌及拉剪强度。采用光学显微镜对接头微观组织进行分析,研究发现焊接接头呈非对称分布,前进侧材料混合更加充分,后退侧界面附近存在孔洞缺陷;整个横截面可以分为母材、热影响区、热机影响区和焊核区,焊核区存在洋葱环形貌。拉剪实验结果表明,随着旋转速度的增加,接头的拉剪强度提升,但是由于接头存在孔洞缺陷,最高拉剪强度仅有120 MPa。

The morphology and tensile-shear strength of friction stir welded joint of 7075/5083 dissimilar aluminum alloy were studied.The microstructure of the joint is analyzed by optical microscope,and it is found that the welded joint is asymmetrically distributed,the material on the advancing side is mixed more fully,and there are holes near the interface of the retreating side.The whole cross section can be divided into base metal,heat affected zone,heat engine affected zone and welding core zone,and there is onion ring morphology in the welding core zone.The tension-shear test results show that the tension-shear strength of the joint increases with the increase of rotation speed,but due to the hole defect of the joint,the maximum tension-shear strength is only 120 MPa.