Recent progress in high-entropy alloys for laser powder bed fusion: Design, processing, microstructure, and performance

Laser powder bed fusion (LPBF), as the most commercialized metal additive manufacturing technique, is tantalizing the metallurgical community owing to its capabilities of directly producing highly intricate parts with complex geometries and achieving superior properties compared to those of conventionally manufactured alloys. High-entropy alloys (HEAs) represent a class of novel materials consisting of multiple principal elements in near-equiatomic ratios, revolutionizing the alloy design concept. LPBF has been employed to fabricate HEAs in numerous attempts to improve their outstanding mechanical, physical, and chemical properties. This review systematically compares seven unique classes of LPBF-produced HEAs—the 3d transition metal HEAs, eutectic HEAs, precipitation-strengthened HEAs, refractory HEAs, metastable HEAs, interstitial HEAs, and high-entropy matrix composites—pertaining to their feedstock preparation, printability, microstructure, strengthening mechanisms, material properties, and potential applications. Additionally, the computational modeling of HEAs for LPBF is extensively discussed. This work aims to guide relevant research in the field by systematically reviewing the advancements in the design strategies employed for the successful fabrication of HEAs by LPBF.