Journal of the Korean Society of Propulsion Engineers ISSN:1226-6027(Print) 2288-4548(Online) 한국추진공학회지

Friction Stir Welding (FSW) is a solid-state joining technology developed in the early 1990s by the UK's TWI (The Welding Institute). Unlike conventional welding methods, it joins materials without melting them, minimizing thermal distortion and defects, and enhancing the strength and durability of weld joints. Additionally, FSW reduces reliance on the operator’s skill level; instead, the quality is determined by the precision of the tooling and the stability of the welding conditions, allowing for consistent mass production of high-quality welds. This research aims to develop a common bulk propellant tank as part of the Space Pioneer Project. It focuses on the design and fabrication of high-precision tooling required for the FSW process, particularly through the development of a dome axial welding fixture, which contributes to maintaining the shape of structures and ensuring consistent welding quality. This fixture is designed to reduce distortion during the welding process and maintain uniform welding pressure. The FSW tooling developed by domestic researchers has contributed to narrowing the technology gap with advanced countries and is expected to play a crucial role in the future expansion of next-generation launch vehicles and space-related technologies. This achievement marks the first application of FSW technology to large circular and complex structures in the country, serving as an important milestone for innovative manufacturing processes. Through the commercialization and advancement of the FSW technology developed in this research, we anticipate improvements in manufacturing efficiency for large structures, driving innovation not only in the domestic space industry but also in the aerospace, shipbuilding, and automotive sectors. This is expected to significantly enhance the competitiveness of domestic manufacturing.