Ceramic Particle‐Reinforced Medium‐Entropy Alloys With Outstanding Mechanical Properties Prepared by Novel Micro‐LPBF

ABSTRACT Additive manufacturing of multi‐principal element alloys is a promising approach for fabricating functional materials. A medium‐entropy alloy (MEA) composite was fabricated using micro‐scale laser powder bed fusion (µ‐LPBF) with nano‐ceramic particle doping, exhibiting a notable strength‐ductility synergy. The microstructural evolution, mechanical properties, and deformation mechanisms of the composite were systematically investigated. The unique µ‐LPBF process and subsequent aging treatment enabled the composite to exhibit good properties, including high hardness (557.5–789.1 HV), excellent tensile strength (1675 MPa), and uniform elongation (28%). Furthermore, the tensile strength was increased to 1817 M Pa via ceramic particle doping, without compromising the ductility at 18%. Ultra‐high temperature gradients and cooling rate in µ‐LPBF are conducive to grain refinement and the simultaneous activation of multiple strengthening mechanisms, thereby enhancing strain‐hardening and ductility. The enhanced performance of the MEA, including tensile strength, corrosion resistance, and wear resistance arise mainly from synergistic multi‐level microstructures, featuring segregation‐induced dislocation banding, ultrafine γ′ precipitates, Cr‐rich σ ‐phase precipitates with controlled fraction and morphology, dense 9R phase, high‐density dislocations, dense nanotwin/microband networks, Lomer‐Cottrell locks, and related crystallographic defects. The novel alloy design, combined with a streamlined, optimized processing strategy, plays a crucial role in developing multi‐component alloys and composites with outstanding mechanical properties.