7075铝合金搅拌摩擦焊接头组织与力学性能研究

Microstructure and Mechanical Properties of Welded Joint of 7075 Aluminum Alloy by FSW

利用搅拌摩擦焊方法对7075铝合金板进行焊接,探讨了焊接速度和搅拌头旋转速度等焊接工艺参数对焊缝成形及接头力学性能的影响,并对焊接接头的显微组织进行了分析。结果表明:采用搅拌摩擦焊焊接7075铝合金时,焊接接头具有较好抗拉性能。当旋转速度为750r/min、焊接速度为95mm/min时,焊接接头的强度最高,达到母材抗拉强度(487MPa)的97.4%,并且其伸长率也较高(为3.1%);当旋转速度为950r/min、焊接速度为150mm/min时焊接接头的伸长率最好,为4.7%。总体上看,焊接接头的伸长率和母材相比较低。

The welding experiments of 7075 aluminum alloy sheet were carried out by frication stir welding,the influences of welding speed and friction tool rotation speed on the morphology of weld and mechanical properties were investigated,and the microstructure of the welded joint was studied.The results show the welded joint of 7075 aluminum alloy welded by FSW has high tensile strength.The tensile strength of the welded joint is highest under the condition of the friction tools rotation speed 750r/min and the weld speed 95mm/min,which can reach 97.4% of parent material（487MPa）,and the specific elongation of the test piece reachs 3.1%.The specific elongation of welded joint is highest under condition of rotation speed 950 r/min and weld speed 150 mm/min,which can reach 4.7%.As a whole,the specific elongation of the welded joint is smaller than that of basic material.