【摘要】 为研究2A12/7075异种铝合金搅拌摩擦焊接头耐晶间腐蚀性能,对异种铝合金2A12/7075进行对接搅拌摩擦焊(FSW),焊接后对接头进行组织观察和晶间腐蚀实验。结果表明,接头焊核区(NZ)发生完全动态再结晶,该区域晶粒平均尺寸约为7.8μm;前进侧热机影响区晶粒大小约为10.5μm,回退侧热机影响区晶粒大小约为12.3μm。前进侧热影响区晶粒长度约610μm,宽度约42.8μm;回退侧热影响区晶粒长度约71.7μm,宽度约21.9μm。焊核区耐晶间腐蚀性能良好,仅达到2级腐蚀,其腐蚀深度为15.6μm;母材部分7075铝合金腐蚀情况严重,已经达到5级腐蚀,其深度最大值为379.7μm;2A12侧母材表现出良好的耐晶间腐蚀性能,达到3级腐蚀,深度为57.6μm。热影响区晶粒都有所长大,前进侧热影响区更为明显。接头前进侧抗晶间腐蚀性能整体不如回退侧,而腐蚀深度仅为15.6μm的焊核区表现出了最优良的耐腐蚀性能。2A12-T4母材耐晶间腐蚀性能好于7075-T6母材。更多还原

【Abstract】 In order to study the intergranular corrosion resistance of 2 A12/7075 dissimilar aluminum alloy friction stir welded joints,the dissimilar Friction Stir Welding(FSW)of dissimilar aluminum alloy 2 A12/7075 was carried out.After welding,the joints were observed and intergranular corrosion test were carried out.The results show that the nugget zone(NZ)undergoes complete dynamic recrystallization,and the average grain size of the zone is 7.8μm.The grain size of the advancing side heat affected zone is about 10.5μm,and the grain size of the retreating side heat engine affected zone is about 12.3μm.The grain length of the Heat Affected Zone(HAZ)on the advancing side is about 610μm and the width is about 42.8μm.The grain length of the heat affected zone on the retreating side is about 71.7μm and the width is about 21.9μm.The intergranular corrosion resistance of the entire nugget zone is very good and only reaches the grade 2 corrosion,and its corrosion depth is 15.6μm.The base metal part 7075 is seriously corroded and has reached grade 5 corrosion.The maximum corrosion depth is 379.7μm,and the 2 A12 base material shows good intergranular corrosion resistance,with the maximum corrosion depth of 57.6μm.The grains in HAZ have grown up,and the heat-affected zone on the advancing side is more obvious.As a whole,the intergranular corrosion resistance of the advancing side is inferior to the retreating side,while the intergranular corrosion resistance of NZ is the best with the maximum corrosion depth is only 15.6μm.The intergranular corrosion resistance of 2 A12-T4 base material is better than that of 7075-T6 base metal.更多还原