针对6A02铝合金搅拌摩擦焊缝中易出现S线的问题,对10 mm厚6A02-H112铝合金轧制板进行搅拌摩擦焊接,研究焊后热处理对焊接接头性能的影响。结果表明,热处理使6A02铝合金FSW接头的强度和塑性大幅降低。拉伸试样横截面显微组织和断口形貌分析显示,焊接态FSW焊缝焊核区存在S线特征,且在焊缝中部向后退侧偏移。焊态试样在母材区发生断裂。热处理后,显微硬度显著提高,S线处硬度值相对较小,试样裂纹沿S线断裂,断口呈脆性断裂。 Aiming at the S-line problem appearing in the friction stir welding of 6A02 aluminum alloy, the friction stir welding of 10mm thick 6A02-H112 aluminum alloy rolling plate was carried out to study the effect of post-weld heat treatment on the performance of welded joint. The results show that the strength and ductility of 6A02 aluminum alloy FSW joint are greatly reduced by heat treatment. Tensile cross-section microstructure and fracture surface morphology analysis showed that welding FSW weld nugget area exists S-line characteristics, and in the middle of the weld to the back side shift. Weld test specimen in the base material fracture. After heat treatment, the microhardness increases significantly, and the hardness value of S line is relatively small. The crack of the specimen breaks along the S line and the fracture is brittle fracture.