Abstract This research work describes the development of autogenous orbital gas tungsten arc welding for oxygen-free copper pipe. Neutral beam system for fusion devices consists of the different water-cooled component, which is designed and fabricated from pure copper to have the excellent thermal and electrical conductivity from the functionality point of view. Due to their application in a high vacuum along with the nuclear environment, a weld joint of full penetration configuration with a 100% volumetric examination is a mandatory requirement. Welding of pure copper has always been a challenging task because of its high conductivity and reflectivity, even with the use of high energy beam welding techniques (e.g., Electron beam welding and laser beam welding). Further, to compensate the heat dissipation, if the higher arc energy is provided to the base material, it results in the loss of strength, and therefore the selection of welding process and determining the parameters plays a crucial role for pressure withstanding welded connections. Though electron beam welding is a conventionally practiced process for welding of pure copper, the need for massive infrastructure limits its applicability to the large components. The present aim to have an understanding of the applicability of pulsed TIG process, in an autogenous mode for welding of pure copper material is presented. During this research work range of process parameters were used to assess the quality and strength of the joint. The range of process parameters was used to retain the mechanical properties of base material to the extent possible level. While doing, so weldability assessment was made for the shielding gas, welding program (pulse current, background current, and their duty cycles), joint geometry, arc length, and heat inputs. The mechanical and microstructural properties have been evaluated for the range of these parameters. The results have also been compared with the properties achieved by the electron beam welding process to understand what best researchers can achieve with the conventional welding process compared to high energy beam welding.

中文翻译：

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铜管自熔焊接采用轨道 TIG 焊接技术作为核聚变装置的高真空边界件

摘要 本研究工作描述了无氧铜管自体轨道钨极气体保护焊的发展。聚变装置的中性束系统由不同的水冷组件组成，该组件由纯铜设计和制造，从功能的角度来看具有出色的导热性和导电性。由于它们在高真空和核环境中的应用，具有 100% 体积检查的全熔透配置的焊接接头是强制性要求。纯铜的焊接一直是一项具有挑战性的任务，因为它具有高导电性和反射率，即使使用高能束焊接技术（例如，电子束焊接和激光束焊接）也是如此。此外，为了补偿散热，如果向母材提供较高的电弧能量，则会导致强度损失，因此焊接工艺的选择和参数的确定对焊接连接的耐压起着至关重要的作用。尽管电子束焊接是一种传统的纯铜焊接工艺，但对大型基础设施的需求限制了其对大型部件的适用性。目前的目的是了解脉冲 TIG 工艺的适用性，提出了在纯铜材料焊接的自生模式下。在这项研究工作中，使用一系列工艺参数来评估接头的质量和强度。工艺参数范围用于尽可能保持基材的机械性能。在做的时候，因此，对保护气体、焊接程序（脉冲电流、背景电流及其占空比）、接头几何形状、电弧长度和热输入进行了可焊性评估。已针对这些参数范围评估了机械和微观结构特性。还将结果与电子束焊接工艺所获得的特性进行了比较，以了解与高能束焊接相比，最佳研究人员可以通过传统焊接工艺获得什么。