Large ship propellers are still commonly made by casting molten metal in molds, a process that can take considerable time and material. UNIST and Ulsan-based 3D Factory are developing an alternative that combines metal additive manufacturing with AI to produce and validate a 5-meter-class propeller at full scale.

The 54-month project will span design for additive manufacturing (DfAM), full-scale fabrication, performance validation, and classification approval. Led by the UNIST 3D Printing Convergence Technology Center in partnership with 3D Factory, the project will receive KRW 11 billion in funding, including KRW 8.5 billion in government support under the   2026 Shipbuilding and Marine Industry Technology Development Program of the Ministry of Trade, Industry and Energy (MOTIE).

Producing a propeller at this scale presents particular challenges for additive manufacturing. Propeller blades have complex curved surfaces and varying thicknesses, while heat generated during metal deposition can cause distortion and residual stress that affect the final shape.

The team will use wire arc additive manufacturing (WAAM), which melts metal wire with an electric arc and deposits it layer by layer. Because the process builds directly from digital designs without conventional molds, it could reduce production time and material waste while offering greater flexibility in manufacturing complex components. UNIST has previously highlighted 3D Factory's work applying WAAM to mobility manufacturing.

To improve accuracy at this scale, UNIST will develop DfAM methods tailored to large propeller blades and use AI to analyze data from design, deposition, and inspection. By predicting thermal deformation and residual stress during fabrication, researchers aim to compensate for distortion before it occurs and improve the dimensional accuracy of the finished component.

The technology could also have applications in naval maintenance, repair, and overhaul (MRO), where replacement or discontinued parts may be difficult to source. Manufacturing components directly from digital design data could allow parts to be produced closer to where they are needed and reduce reliance on conventional supply chains.

UNIST and 3D Factory presented their metal additive manufacturing and AI-based manufacturing capabilities in Washington, DC, in July at the Openning Ceremony of the Korea-US Shipbuilding Cooperation Center and the Korea-US Joint R&D Technology Exchange Forum. The events brought the team together with representatives from the US Navy and the US shipbuilding industry.

If successfully validated and certified, the technology could open opportunities to enter the US naval component supply chain and other overseas markets. The project is also expected to serve as a demonstration model for MASGA (Make American Shipbuilding Great Again), the Korea-US shipbuilding cooperation initiative.

Ulsan City plans to support subsequent commercialization and overseas market development, drawing on the region's established shipbuilding and manufacturing base.

“The key to this project is not simply producing a five-meter-scale component, but demonstrating DfAM and AI-based distortion compensation at full scale,” said Namhun Kim, Director of the UNIST 3D Printing Convergence Technology Center. “By combining UNIST's research capabilities with Ulsan's shipbuilding infrastructure, we aim to establish a new approach to manufacturing large ship components and develop it into a model for Korea-US shipbuilding cooperation.”