Hybrid Processes in Additive Manufacturing

TLDR

Hybrid additive manufacturing integrates multimaterial, multistructural, and multifunctional printing, reshaping design rules and emphasizing part quality and performance over mere process improvement. The study aims to define hybrid‑AM relative to hybrid manufacturing, classify its processes, and highlight the need for economic, sustainability, and sensing tools as the field expands. Hybrid‑AM is characterized by fully coupled additive and secondary processes—such as machining, remelting, peening, rolling, and friction stir processing—in a cyclic chain that synergistically enhances part quality and performance. Hybrid‑AM represents the next evolutionary step in additive manufacturing, poised to profoundly transform how goods are produced.

Abstract

Hybrid additive manufacturing (hybrid-AM) has described hybrid processes and machines as well as multimaterial, multistructural, and multifunctional printing. The capabilities afforded by hybrid-AM are rewriting the design rules for materials and adding a new dimension in the design for additive manufacturing (AM) paradigm. This work primarily focuses on defining hybrid-AM in relation to hybrid manufacturing (HM) and classifying hybrid-AM processes. Hybrid-AM machines, materials, structures, and function are also discussed. Hybrid-AM processes are defined as the use of AM with one or more secondary processes or energy sources that are fully coupled and synergistically affect part quality, functionality, and/or process performance. Historically, defining HM processes centered on process improvement rather than improvements to part quality or performance; however, the primary goal for the majority of hybrid-AM processes is to improve part quality and part performance rather than improve processing. Hybrid-AM processes are typically a cyclic process chain and are distinguished from postprocessing operations that do not meet the fully coupled criterion. Secondary processes and energy sources include subtractive and transformative manufacturing technologies, such as machining, remelting, peening, rolling, and friction stir processing (FSP). As interest in hybrid-AM grows, new economic and sustainability tools are needed as well as sensing technologies that better facilitate hybrid processing. Hybrid-AM has ushered in the next evolutionary step in AM and has the potential to profoundly change the way goods are manufactured.