High-entropy alloys (HEAs) have received considerable interest over the past decade due to their intriguing structural, chemical, and physical properties. Additive manufacturing (AM), also termed three-dimensional (3D) printing, generates parts with complex geometries and internal features layer-upon-layer from a computer-aided design (CAD) 3D file. In recent years, explosive research on AM of HEAs has been inspired. This paper performs a comprehensive and critical review on the recent progress in additively manufactured (AM-ed) HEAs, with a special focus placed on the similarities and differences in the microstructure and mechanical behavior between the AM-ed HEAs and the as-cast or thermo-mechanically processed (TMP-ed) counterparts. To gain a better understanding of the formation of the AM microstructure, the working principles, rapid solidification effects, and subsequent thermal cycling effects of various metal AM techniques, e.g., directed energy deposition (DED), selective laser melting (SLM), and electron beam melting (EBM), are also introduced. In the end, several future research directions are suggested towards the design of advanced HEAs with the superior strength-ductility synergy via 3D printing.

高熵合金 (HEA) 由于其有趣的结构、化学和物理特性，在过去十年中受到了极大的关注。增材制造 (AM)，也称为三维 (3D) 打印，可根据计算机辅助设计 (CAD) 3D 文件逐层生成具有复杂几何形状和内部特征的零件。近年来，HEAs 的 AM 研究受到了启发。本文对增材制造 (AM-ed) HEA 的最新进展进行了全面而批判性的回顾，特别关注了增材制造 (AM-ed) HEA 与铸态或热机械加工 (TMP-ed) 对应物。为了更好地了解增材制造微结构的形成、工作原理，还介绍了各种金属 AM 技术的快速凝固效应和随后的热循环效应，例如定向能量沉积 (DED)、选择性激光熔化 (SLM) 和电子束熔化 (EBM)。最后，提出了几个未来的研究方向，旨在通过 3D 打印设计具有优异强度-延展性协同作用的先进 HEA。