Jumaev Elyorjon, Park Hae-Jin, Abbas Muhammad Aoun, Yusupov Dilshodbek, Hong Sung-Hwan, Kim Ki-Buem
FIE UzLITI Engineering LLC, 28B Beshyogoch, Tashkent 100066, Uzbekistan.
Department of Nanotechnology and Advanced Materials Engineering, Sejong University, 209, Neungdong-ro, Gwangjin-gu, Seoul 05006, Republic of Korea.
Materials (Basel). 2024 Jul 22;17(14):3617. doi: 10.3390/ma17143617.
This study examines the microstructural evolution and mechanical properties of quaternary AlCoCrNi high-entropy alloys after heat treatment at 873 K for 72 and 192 h. The changes in nanostructure and phase transformation based on the heat treatment duration were as follows: B2 dendrite + BCC interdendrite and sigma phases after 72 h; B2 dendrite and interdendritic sigma phases + BCC after 192 h. After annealing, the morphology of the dendritic region shifted from spherical to needle-like, and the interdendritic region transformed from a spinodal-like to a plate-like morphology. Additionally, a phase transformation was observed in the dendritic regions of the annealed alloys at the nano-scale. The presence of the sigma phase in AlCoCrNi high-entropy alloys significantly improved the yield strength to around 1172 MPa; nevertheless, it decreased the compressive strain rapidly to 0.62%.
本研究考察了四元AlCoCrNi高熵合金在873 K下分别热处理72小时和192小时后的微观结构演变和力学性能。基于热处理时间的纳米结构和相变变化如下：72小时后为B2枝晶+BCC枝晶间和西格玛相；192小时后为B2枝晶和枝晶间西格玛相+BCC相。退火后，枝晶区域的形态从球形转变为针状，枝晶间区域从类调幅分解形态转变为板状形态。此外，在退火合金的枝晶区域纳米尺度上观察到了相变。AlCoCrNi高熵合金中西格玛相的存在显著提高了屈服强度至约1172 MPa；然而，它使压缩应变迅速降至0.62%。
