6082铝合金搅拌摩擦焊接头性能及腐蚀行为

成功实现3 mm厚6082铝合金搅拌摩擦焊接，探究了不同焊速对其接头力学性能的影响，并对接头的腐蚀性能展开研究。结果表明：焊速从80 mm/min增大到120 mm/min的过程中接头抗拉强度增大较快，在120 mm/min时抗拉强度最大，为200.36 MPa。晶间腐蚀实验表明接头在不同时间内均发生了晶间腐蚀，这是由于晶界处析出的第二相粒子与晶粒内部产生了电位差。随着时间的增加，腐蚀逐渐向晶粒内部扩展，最终发展成腐蚀坑。微区电化学和浸泡腐蚀实验表明热影响区的平均阻抗值最低，耐腐蚀性能最差，而焊核区表现出最佳的耐腐蚀性。

Study on properties and corrosion behavior of 6082 aluminum alloy friction stir welding joints

In this paper, friction stir welding of 3mm thick 6082 aluminum alloy was successfully realized, and the influence of different welding speeds on the mechanical properties of the joint was investigated, and the corrosion properties of the joint was studied. The results show that the tensile strength of the joint increases rapidly when the welding speed increases from 80mm/min to 120mm/min. The maximum tensile strength is 200.36 MPa at 120mm/min, which reaches 63.6 % of the strength of the base metal. The intergranular corrosion experiment showed that the joint had intergranular corrosion at different times, which was due to the potential difference between the second phase particles precipitated at the grain boundary and the grain interior. With the increase of time, the corrosion gradually extended to the interior of the grains and eventually developed into corrosion pits. The local electrochemical and immersion corrosion experiments show that the average impedance value of the heat affected zone is the lowest, and the corrosion resistance is the worst, while the weld nugget zone shows the best corrosion resistance.