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采用双轴肩搅拌摩擦焊(BTFSW)技术对7.8 mm厚6061-T6铝合金进行了焊接,对焊接接头各部分的微观组织和截面显微硬度进行了分析,并对母材和焊核在3.5%Na Cl溶液中的腐蚀电化学行为和腐蚀产物膜进行了研究.结果表明,BTFSW后焊缝表面质量良好,热-机影响区晶粒发生再结晶和塑性变形,部分再结晶晶粒发生了伸长和弯曲;热影响区的部分晶粒在热循环的作用下发生粗化,焊核呈细小的等轴晶组织;焊接接头中前进侧热-机影响区硬度最低;在3.5%Na Cl溶液中,6061-T6铝合金的极化曲线表现为阳极溶解和点蚀,母材和焊核区的电化学阻抗谱均由容抗弧和感抗弧组成,BTFSW后6061铝合金的腐蚀电流降低;浸泡480 h后,呈疖状腐蚀的特征,腐蚀产物为Al(OH)3和Al2O3.BTFSW可提高6061-T6铝合金的耐蚀性.
The double-shouldered friction stir welding (BTFSW) technology was used to weld the 7.8 mm thick 6061-T6 aluminum alloy. The microstructure and cross-section microhardness of each part of the welded joint were analyzed. % NaCl solution.The results show that the surface quality of the weld is good after BTFSW and recrystallization and plastic deformation occur in the heat affected zone and some recrystallized grains occur Elongation and bending; part of the heat-affected zone grains coarsening under the action of thermal cycling, the weld nuclei are fine equiaxed grain structure; welded joints in the advancing side of the heat-machine affected zone hardness lowest; 3.5% NaCl In the solution, the polarization curve of 6061-T6 aluminum alloy showed anodic dissolution and pitting corrosion. The electrochemical impedance spectroscopy of the base metal and the nugget area consisted of capacitive arc and reactive arc. The corrosion current of 6061 aluminum alloy after BTFSW And the corrosion products were Al (OH) 3 and Al2O3.BTFSW can improve the corrosion resistance of 6061-T6 aluminum alloy.