The domestic industrial base requires reliable, scalable methods to rapidly manufacture large (>1 ton) components due to the diminishment in recent decades of domestic casting and forging capacity. Large-scale metal additive manufacturing with wire arc welding processes is a promising method to augment the domestic supply chain, but individual-printhead deposition rates limit scalability to meet the needs of the largest components. By contrast, Electro-Slag Additive Manufacturing (ESAM) utilizes precise gas metal arc welding (GMAW) printed walls to define and contain the large slag- and melt-pools that are subsequently deposited via electroslag strip cladding (ESC). This synergistic combination has demonstrated deposition rates greater than 5x those reported by conventional WAAM. Utilizing a strip electrode of 30-60+ mm width, ESAM is especially well-suited to the production of heavy-section components. An overview of the fundamentals and development history of ESAM is provided, with the role of modern advancements in automation and tool pathing highlighted. We characterize the mechanical properties and residual stresses of geometries manufactured on a custom ESAM system and use these results along with a time- and motion- study to develop a quantitative estimate for the scaling relationship between deposition rate and component size. An outlook for future research, development, and deployment activities is also provided.
Learning Objectives:
Upon completion, participants will know more about strip-cladding and it's role in high-throughput metal additive manufacturing.
Upon completion, participants will understand opportunities to make large metallic structures domestically without relying on overseas foundries and casting houses.
