A Hybrid Additive-Forging Approach for Low Volume Defense-Grade Forging Applications

In forging industries, the design and fabrication of preforms are critical for achieving defect-free metal flow and complete die cavity filling with minimal material loss. Conventional manufacturing of complex forgings often requires 2–7 preforming steps, resulting in increased strain accumulation, tooling costs, and long lead times. Moreover, extensive thermo-mechanical processing is needed to achieve a homogenized structure, while die machining and heat treatment can take up to six months and cost between $100K and $500K. Additive Manufacturing (AM) offers a transformative alternative by enabling the fabrication of intricate, near-net-shape preforms in fewer steps, thereby reducing tooling requirements, lead time, and overall cost while promoting material and energy efficiency. In this study, two AM routes Laser Powder Bed Fusion (L-PBF) and Directed Energy Deposition (DED) were employed to fabricate preforms with geometries approximating the final forged shape. Microstructural and mechanical characterizations were conducted at different locations within the preforms to evaluate process-induced variations. Hot compression tests at varying temperatures, strain rates, and true strains were performed to design and optimize the preform geometry for forging applications. A simulation-based approach was used to optimize the AM preform design, which was subsequently fabricated using the L-PBF and wire Arc-DED processes. This research demonstrates the potential of integrating AM into low-volume forging operations for defense applications, offering a pathway to expand product capabilities, shorten production cycles, and open new market opportunities for the forging industry.