“Advances in wire-arc additive manufacturing of nickel-based superalloys: Heat sources, DfAM principles, material evaluation, process parameters, defect management, corrosion evaluation and post-processing techniques”

Wire arc additive manufacturing (WAAM) has increasingly been recognized as a cost-effective method for fabricating intricate metallic parts, especially from nickel-based superalloys. This review covers key aspects of WAAM, including its versatile heat sources (GTAW, GMAW, CMT, and PAW) with unique advantages and limitations for customization. Design for Additive Manufacturing (DfAM) principles are highlighted, enabling intricate geometries and addressing support structures, distortion control, and orientation.

Several nickel-based superalloys (e.g., Inconel 718, Inconel 625, Inconel 617, Hastelloy C276, Hastelloy X, Haynes 282) are rigorously evaluated for WAAM suitability due to their high-temperatureature strength, corrosion resistance, and mechanical properties. The review analyzes process parameters like arc current, wire feed rate, and deposition path. It explores defect detection and prevention strategies and emphasizes post-processing methods (heat treatment, rolling, hot isostatic pressing) in enhancing microstructural characteristics and mechanical properties.

Microstructural characterization techniques (optical microscopy and XRD) provide insights into grain structure, phase composition, and defect presence. In conclusion, this review underscores the paramount suitability of WAAM for producing defect-free and complex structures in nickel-based superalloys. Ongoing research and advancements in WAAM will undoubtedly improve its competitiveness and unlock its full potential in the field of additive manufacturing.