Invited: Extending the Useful Life of Hydroelectric Turbine Components Using a Hybrid CSAM/WAAM Repair Approach

Given the compelling challenges that our planet is currently facing, sustainable manufacturing concepts & processes that can contribute to the circular economy are more critical than ever. In this context, there is a growing interest for cost-effective, environmentally friendly methods meant to repair components that have been damaged or worn, as opposed to simply replacing them. One example is the repair and life extension of hydroelectric turbine components, which represents a critical challenge due to their geographical locations & complex geometries, the limited weldability of certain alloys, and the need to minimize distortion and downtime. Solid‑state cold spray additive manufacturing (CSAM) and wire‑arc additive manufacturing (WAAM) each offer distinct advantages for repair: CSAM enables dense, low‑heat deposition of a wide range of materials, while WAAM provides high deposition rates and efficient material buildup for large‑scale features. This work explores a hybrid CSAM/WAAM repair strategy aimed at leveraging the complementary strengths of both technologies.

The presentation will discuss the rationale behind process sequencing, material selection, and interfacial considerations when combining these two additive repair approaches. Emphasis will be placed on how solid‑state and fusion‑based deposition can be integrated to address geometric restoration, surface integrity, and restoration requirements simultaneously. Preliminary observations from component representative trials (wear, hardness and adhesion for instance) will be shared, highlighting opportunities, limitations, and areas requiring further development.