Effects of annealing on microstructure and mechanical properties of powder metallurgy hot rolled CoCrFeNiC0.05 high-entropy alloy sheet
ZHANG Yangfan1, ZHOU Rui2, TAO Hui1, LI Huizhong1,3, LIANG Xiaopeng1,3
1. School of Materials Science and Engineering, Central South University, Changsha 410083, China; 2. Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong 999077, China; 3. Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083, China
Abstract：The pre-alloyed powder was prepared by gas atomization method with Cr, Co, Fe, Ni simple substance and Cr3C2 as raw materials. CoCrFeNiC0.05 high-entropy alloy was prepared by hot isostatic pressing, and the alloy was hot rolled and annealed. The effects of annealing on the microstructure and mechanical properties of powder metallurgy hot rolled CoCrFeNiC0.05 high-entropy alloy sheet were systematically studied by X-ray diffraction, optical microscope, scanning electron microscope, transmission electron microscope, electron backscatter diffraction, Vickers hardness, and tensile testing. The results show that the grains are equiaxed in hot isotactic pressed alloy but transform to elongated morphology after hot rolling. The hot rolled sheet exhibits a strong F-type texture, and twins and submicron Cr23C6 typed carbide are observed. After annealing treatment at 800 ℃, the alloy undergoes complete recrystallization. Hot rolling combining with moderate temperature annealing (500 ℃) is an effective approach to achieving good comprehensive mechanical properties for CoCrFeNiC0.05 high-entropy alloy, with yield strength of 961 MPa, tensile strength of 1 023 MPa, and elongation of 13.6%.
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2023, Vol. 28 
