Frontiers in high entropy alloys and high entropy functional materials

Owing to their exceptional properties, high-entropy alloys (HEAs) and high-entropy materials have emerged as promising research areas and shown diverse applications. Here, the recent advances in the field are comprehensively reviewed, organized into five sections. The first section introduces the background of HEAs, covering their definition, significance, application prospects, basic properties, design principles, and microstructure. The subsequent section focuses on cutting-edge high-entropy structural materials, highlighting developments such as nanostructured alloys, grain boundary engineering, eutectic systems, cryogenic alloys, thin films, micro-nano-lattice structures, additive manufacturing, high entropy metallic glasses, nano-precipitate strengthened alloys, composition modulation, alloy fibers, and refractory systems. In the following section, the emphasis shifts to functional materials, exploring HEAs as catalysts, magneto-caloric materials, corrosion-resistant alloys, radiation-resistant alloys, hydrogen storage systems, and materials for biomedicine. Additionally, the review encompasses functional high-entropy materials outside the realm of alloys, including thermoelectric, quantum dots, nanooxide catalysts, energy storage materials, negative thermal expansion ceramics, and high-entropy wave absorption materials. The paper concludes with an outlook, discussing future directions and potential growth areas in the field. Through this comprehensive review, researchers, engineers, and scientists may gain valuable insights into the recent progress and opportunities for further exploration in the exciting domains of high-entropy alloys and functional materials. Graphic abstract: (Figure presented.)