Emerging Material Systems and Alloy Design Strategies in Metal Additive Manufacturing: Current Trends and Future Directions

Metal Additive Manufacturing (MAM) has emerged as a transformative technology capable of producing complex, lightweight, and high-performance components for aerospace, biomedical, energy, and automotive sectors. Its growing industrial adoption highlights the importance of developing material systems specifically tailored to the unique thermal conditions and rapid solidifi-cation environments of AM processes. However, a major gap remains between the capabilities of current alloy systems, many of which were originally designed for traditional manufacturing and the demanding requirements of MAM, including resistance to hot cracking, control of microstructural anisotropy, and mitigation of residual stress. Addressing this gap is essential for expand-ing the reliability and functionality of AM-produced components. This review examines emerging alloy design strategies and ad-vanced material systems engineered to improve printability, microstructure stabilization, and performance in metal AM. Key find-ings indicate significant progress in developing high-entropy alloys, metastable and compositionally graded systems, and AM-specific superalloys that offer enhanced solidification behavior and mechanical robustness. Additionally, recent advancements in integrated computational materials engineering (ICME), rapid solidification modeling, and machine-learning-driven composition optimization are accelerating the discovery of next-generation AM alloys. The literature also highlights the growing role of in-situ alloying and feedstock modification as practical pathways for tuning microstructure during fabrication. The implications of these findings suggest a paradigm shift: instead of adapting conventional alloys for AM, future progress will rely on designing composi-tions explicitly for additive environments. Such innovations are expected to expand the printable alloy portfolio, enhance process stability, and enable superior component performance across high-impact industries.