5083/6005A异种铝合金搅拌摩擦焊接头组织与性能

Microstructure and Properties of Friction Stir Welded Joints for 5083/6005A Dissimilar Aluminum Alloy

采用不同的工艺参数对5083-OT与6005A-T6铝合金进行搅拌摩擦焊焊接。通过金相分析、XRD分析、拉伸性能等方法,研究焊接速度、轴肩直径及搅拌头偏移量等参数对5083/6005A异种铝合金搅拌摩擦焊接头组织与性能的影响。结果表明:5083/6005A异种铝合金搅拌摩擦焊界面无明显脆性金属间化合物生成;焊核区组织发生动态再结晶,形成细小的等轴晶组织;前进侧热机影响区受到的机械搅拌作用力大于后退侧,晶粒变形大于后退侧热机影响区;热影响区组织仅受到热循环的作用,晶粒有粗化现象;随着偏移量的增加,使得焊核区和后退侧热机影响区硬度值降低,最低值出现在6005A侧热影响区,其抗拉强度、屈服强度、延伸率均逐渐减小,当焊接速度为600 mm/min、轴肩直径为12 mm、偏移量为0 mm时接头性能最好:抗拉强度为245 MPa,屈服强度为165 MPa,延伸率为5.67%。

5083-OT and 6005A-T6 aluminum alloys was carried out with different welding process parameters by Friction stir welding.The effects of welding parameters such as welding speed,shoulder diameter and stir head offset on the micro‐structure and properties of 5083/6005A dissimilar aluminum alloy friction stir welded joints were studied by means of metal‐lographic analysis,XRD analysis and tensile properties.The results show that there is no brittle intermetallic compound at the interface of friction stir welding of 5083/6005A dissimilar aluminum alloy;The microstructure of nugget zone undergoes dynamic recrystallization,forming fine equiaxed crystal structure;TMAZ influences of the heat engine on the forward side is greater than that on the backward side,and the grain deformation is greater than that in the zone of influence of the heat engine on the backward side;The microstructure of heat affected zone is only affected by thermal cycle,and the grains are coarsened;With the increase of the offset,it makes the hardness value of the weld core area and the heat machine affected area on the backward side decrease,and the lowest value appears in the heat affected area on the 6005A side,and its tensile strength,yield strength and elongation gradually decrease,and the joint performance is the best when the weld speed is 600 mm/min,the diameter of the shaft shoulder is 12 mm,and the offset is 0mm The tensile strength is 245 MPa,yield strength is 165 MPa,and elongation is 5.67%.