中文摘要：

为了提高传统钨极惰性气体保护（Tungsten inert gas,TIG）焊电弧的能量密度和热源边界的能量梯度,保证焊接热输入均衡,规避输入能量分散,提出空心钨极中心负压电弧焊接方法,设计并构建空心钨极中心负压电弧焊接系统,介绍系统的组成及操作方法。利用高速摄像机拍摄空心钨极中心负压电弧的宏观形态,进行定点焊接烧蚀试验,并对阳极表面熔池尺寸和焊接接头的宏观形貌进行分析。试验结果表明,在电弧自身刚性的作用下,空心钨极中心负压电弧能够稳定地建立于空心钨极和阳极工件之间;与传统TIG焊电弧相比,在宏观形态上,空心钨极中心负压电弧的弧柱沿径向收缩,呈现拘束状,空心钨极的尖端呈现白炽状态;在焊接接头的宏观形貌上,空心钨极中心负压电弧对应焊接接头的熔深大,熔宽小,焊缝成形好。

英文摘要：

In order to enhance the energy density and energy gradient of conventional tungsten inert gas（TIG） arc,ensure a balanced heat input and avoid the dispersion of energy input,the hollow tungsten central negative pressure arc welding method is put forward,the hollow tungsten central negative pressure arc welding system is designed and established,components and operating methods of this system are systematically elaborated. The shape of hollow tungsten central negative pressure arc is observed by using high-speed video camera,the welding ablation experiments at fixed points is carried out,and then the morphology of welded joints of is analyzed. The experiment results refer that hollow tungsten central negative pressure arc can be established stably between the hollow tungsten and work-pieces under the action of the arc itself rigid. Compared to conventional TIG arc,hollow tungsten central negative pressure arc contracts along the radial direction,being binding shape on macro-morphology,the tip of hollow tungsten presents incandescent state. For the macro morphology of welded joints,the weld width becomes narrow,the weld depth becomes deep,and the weld has a better shape.