【摘要】 为研究出一套适合于AM50的TIG焊接工艺,利用TIG焊接技术研究了AM50镁合金的焊接性,并调节工艺参数进行系统焊接试验,同时,对焊接接头也进行了相关的力学性能试验;试验结果表明:焊接电流、焊接速度和气体流量均对焊接接头表面成形性和力学性能产生重大影响,并得到一套完整的焊接工艺规范.经过对其接头进行显微组织分析观察发现,焊接接头组织及第二相的变化导致接头处的拉伸强度和硬度均低于母材,并且焊缝区由基体α-Mg和附集于晶界的β-Al12Mg17两相组成.更多还原

【Abstract】 In order to develop the TIG welding technology suitable to AM50 magnesium alloy,the TIG welding performance of the alloy was studied.The systematic welding experiments were performed by adjusting the technological parameters.And the mechanical properties of the welding joints were experimentally determined.The results show that the welding current,welding velocity and gas feed rate significantly influence the surface forming performance and mechanical properties of the welding joints.And thus,a set of welding procedures has been obtained.The microstructural observation on the welding joints reveals that the microstructure of the weld zone is composed of α-Mg matrix and β-Al12Mg17 phase which distributes at the grain boundaries.Thus,both tensile strength and hardness of the welding joints are lower than those of the base metal.更多还原