Additive Manufacturing of Multimetallic Materials to Achieve Multifunctionality

ABSTRACT Multifunctional materials (MFMs) exhibit multiple useful functions without complex joint mechanisms. Compared with soft MFMs, metallic MFMs are desired due to their superior mechanical properties and durability. However, the design and fabrication of MFMs are daunting tasks, requiring the organic integration of multiple metals and alloys during manufacturing processes. Additive manufacturing, especially directed energy deposition (DED), has the potential in this regard due to its capability to deposit multimaterials site‐specifically. Through carefully programmed printing paths, novel applications arise and achieve functionalities unseen before. Here, we showcase the versatility of such techniques by four case studies of metallic MFMs: (i) tuning magnetic lifting force, (ii) securely and durably embedding information as material fingerprints, (iii) improving conventional ferrofluidic seals, and (iv) possessing programmable mechanical properties. This work demonstrates the possibilities of using DED to achieve multifunctionalities in metallic materials and provides enlightenment to a wide range of engineering applications.