文献类型：期刊文献

英文题名：Phase boundary and defect dependent high cycle fatigue behavior in AlCoCrFeNi2.1 eutectic high-entropy alloy

作者：Yang, Xiaochuan Li, Tianxin Yang, Jiang Wan, Mingpan Zhang, Zhong Huang, Chaowen

第一作者：Yang, Xiaochuan

通信作者：Huang, CW[1]

机构：[1]Guizhou Univ, Coll Mat & Met, Guiyang 550025, Peoples R China;[2]Guizhou Univ, Natl & Local Joint Engn Lab High Performance Met S, Guiyang 550025, Peoples R China;[3]Guizhou Inst Technol, Sch Mat & Energy Engn, Guiyang 550003, Peoples R China;[4]Nanyang Technol Univ, Sch Mech & Aerosp Engn, Singapore 639798, Singapore;[5]Guizhou Univ, Guizhou Prov Key Lab Adv Met Mat & Wires, Guiyang 550025, Peoples R China

第一机构：Guizhou Univ, Coll Mat & Met, Guiyang 550025, Peoples R China

通信机构：corresponding author), Guizhou Univ, Guiyang 550025, Peoples R China.

年份：2026

卷号：206

外文期刊名：INTERNATIONAL JOURNAL OF FATIGUE

收录：;EI(收录号：20260119852611);WOS:【SCI-EXPANDED(收录号:WOS:001658344100001)】；

基金：This work was supported by the National Natural Science Foundation of China (Nos. 52261025 and 52474402) , the Science and Technology Programs of Guizhou Province (Nos. Qiankehe Rencai XKBF [2025] 008, YQK [2023] 009, and CXTD [2023] 009) , and the China Scholarship Council (CSC Selection [2024] 42-202406670003) . The SEM technical support from Shaanxi Qingyan Youce Technology Co., Ltd is acknowledged.

语种：英文

外文关键词：Ni21 Eutectic high-entropy alloy; Microstructure; High cycle fatigue; Fatigue crack initiation; Fatigue crack propagation

摘要：The AlCoCrFeNi2.1 (Ni21) eutectic high-entropy alloy (EHEA) exhibits a dual-phase heterogeneous microstructure that contributes to its high strength and ductility. However, its high cycle fatigue (HCF) damage mechanisms remain insufficiently understood and restrict its practical application. In this study, the HCF behavior of the as-cast Ni21 alloy was systematically investigated. The alloy exhibits a fatigue strength of approximately 297 MPa (6-1 (107)), corresponding to a fatigue ratio (6-1 (107)/YS) of 0.512. Under cyclic loading, dislocations are preferentially activated in the face-centered cubic (FCC) phase and accumulate at phase boundaries (PBs), where they induce stress concentration and trigger fatigue microcrack initiation. Meanwhile, nano-precipitates within the ordered body-centered cubic (B2) phase effectively hinder dislocations transmission across PBs, thereby enhancing resistance to fatigue crack initiation. The combined contribution of the dual-phase microstructure and nano-precipitates plays a critical role in extending fatigue life. Furthermore, fatigue crack propagation is most effectively suppressed when the crack growth direction intersects PBs at angles between 40 degrees and 70 degrees. Considerable scatter in the HCF data is observed, primarily resulting from casting defects such as blowholes. Overall, these findings highlight that further improvements in the HCF performance of Ni21 alloy will require improved casting quality or appropriate thermo-mechanical treatments.