To achieve a stronger joint in GTAW, what is the purpose of adding a filler rod?

Adding a filler rod in Gas Tungsten Arc Welding (GTAW) serves a crucial purpose in enhancing the quality and strength of the weld joint. The primary function of the filler rod is to fill the gaps in the weld pool, ensuring that the molten metal can flow and fuse properly with the base materials being joined. This addition creates a complete and cohesive structure, which not only improves the mechanical strength of the joint but also helps in achieving a more uniform distribution of the welding material.

When a filler rod is introduced, it melts along with the base metals, allowing for a mixture of materials that can include beneficial alloying elements. This can further enhance properties like ductility and resistance to cracking. Additionally, without a filler rod, there may be insufficient material to bridge the joint, potentially leading to weak spots or incomplete fusion, which compromises the overall integrity of the welded assembly. Thus, the role of the filler rod is essential to achieving a strong and durable weld joint in GTAW applications.