Hybrid Manufacturing: A Critical Review on the Integration of Metal Additive Manufacturing and Forming

The increasing demand for mass customization poses significant challenges for traditional manufacturing systems, which frequently lack the flexibility and cost-effectiveness to make highly tailored components. Hybrid manufacturing, specifically the integration of additive manufacturing (AM) and metal forming, has emerged as an attractive approach for overcoming these limitations by combining AM's geometric freedom with the mechanical robustness and productivity of forming procedures. This review presents an in-depth investigation of hybrid techniques that combine powder bed fusion (PBF) or directed energy deposition (DED) with sheet and bulk metal forming. The article begins by providing a conceptual framework that includes definitions and systematic classifications of hybrid processes. It then investigates two main process sequences: forming before additive deposition and AM followed by forming. Case studies of alloys such as titanium, stainless steel, and aluminum alloys have been reviewed to show how hybrid techniques can refine microstructures, reduce porosity, and improve mechanical performance. Enabling procedures, such as interlayer rolling, hammering, and heat treatments, are reviewed as well for their effectiveness in reducing residual stresses and improving part quality. Key challenges are identified, such as sequence sensitivity, residual stress development, interfacial bonding, and anisotropic material behavior. Research gaps have been found in predictive multiphysics modeling, interface optimization, qualification criteria, and sustainability assessment. The review underlines the need to expand investigations to include a wider range of materials, as well as to incorporate data-driven and intelligent process control systems. Finally, this work provides a road map for advancing AM–forming hybrids toward industrial adoption, underlining their potential to develop reliable and customized components for high-performance applications.