AlCoCrFeNi系高熵合金的强化方法研究

High-entropy alloys (HEAs) is also called multi-principal element alloys. Compared with traditional alloys with one or two elements as the principal constituents, the multiple constituent elements design concept of HEAs grants them the unique constituent, phase structure and a series of excellent mechanical properties. Especially in recent years, there are a lot of HEAs with high strength and ductility, which is of great significance to their engineering application. The excellent mechanical performance is closely related to the strengthening mechanism of the alloys, such as grain-boundary strengthening, coherent second phase strengthening and heterogeneous structure strengthening mechanism, which all promote the improvement of the performance of HEAs in various degrees. Therefore, it is crucial to understand the strengthening mechanism of the HEAs in order to improve the mechanical properties of the HEAs and explore new high-strength and high-ductility HEAs. AlCoCrFeNi HEAs is currently one of the most studied HEAs, which can produce different structure through composition adjustment and different thermo-mechanical treatment process, thus inducing different strengthening mechanism. The mechanical properties of AlCoCrFeNi HEAs can be adjusted in a wide range, making it an ideal material to study the strengthening mechanism of HEAs. Based on this, this article focuses on the subject of the strengthening mechanism of AlCoCrFeNi HEAs. In this article, the strengthening mechanism of HEAs in recent years are reviewed, including grain-boundary strengthening, coherent second phase strengthening, incoherent second phase strengthening and heterogeneous structure strengthening. The composition and structure control for HEAs strengthening mechanism and mechanical properties is further expounded. In addition, this paper proposes that the single strengthening mechanism cannot greatly improve the strength of the alloy. By summarizing the multiple strengthening mechanism, it is proposed that the higher strength can be achieved by combining multiple strengthening mechanisms. At last, the future perspective of strengthening mechanism in HEAs is also discussed.