Please wait a minute...
Acta Metall Sin  2020, Vol. 56 Issue (5): 769-775    DOI: 10.11900/0412.1961.2019.00330
Current Issue | Archive | Adv Search |
Precipitation σ Phase Evoluation and Mechanical Properties of (CoCrFeMnNi)97.02Mo2.98 High Entropy Alloy
YAO Xiaofei(), WEI Jingpeng, LV Yukun, LI Tianye
School of Materials Science and Chemical Engineering, Xi′an Technologcal University, Xi′an 710021, China
Download:  HTML  PDF(2496KB) 
Export:  BibTeX | EndNote (RIS)      

Mo in the form of solid solution atom or compound phase is distributed in CoCrFeMnNi high entropy alloy, which has the effect of solution strengthening or second phase strengthening. The method of annealing was used to heat treated (CoCrFeMnNi)97.02Mo2.98 high entropy alloy to investigate effects of σ phase on mechanical properties of (CoCrFeMnNi)97.02Mo2.98 high entropy alloy. SEM, EDS and XRD were used to analyze effects of annealing temperature on precipitation σ phase (CrMo phase) in (CoCrFeMnNi)97.02Mo2.98 high entropy alloy. The mechanical properties were tested by microhardness and tensile test, and the influencing mechanism of σ phase on the mechanical properties was investigated. The results show that with increase of the annealing temperature, the quantity of precipitation σ phase increases in (CoCrFeMnNi)97.02Mo2.98 high entropy alloy, and the σ phase is first precipitated at the grain boundary, and is after precipitated in intracrystalline. The morphologies of σ phase at the grain boundary are changed gradually from tiny strips of discontinuous distribution to thick strip of continuous distribution. With the annealing temperature increases further, the morphologies of σ phase are changed from strip of continuous distribution to granular of continuous distribution. The precipitation σ phases in (CoCrFeMnNi)97.02Mo2.98 high entropy alloy by annealing have the effect of second phase reinforcement, with the annealing temperature increase, the numbers of precipitation σ phase increase, and the hardness and strength both increase, which is obviously at temperature higher than 900 ℃. The σ phase precipitation in intracrystalline, and its refinement, can improve the strength and plasticity of (CoCrFeMnNi)97.02Mo2.98 high entropy alloy synchronously.

Key words:  CoCrFeMnNi high entropy alloy      Mo      annealing      σ phase (CrMo phase)      mechanical property     
Received:  29 September 2019     
ZTFLH:  TG156.1  
Fund: National Natural Science Foundation of China(51901167);Shaanxi Provincial Education Department(2018JK0396);Natural Science Basic Research Program of Shaanxi(2017JM5057)
Corresponding Authors:  YAO Xiaofei     E-mail:

Cite this article: 

YAO Xiaofei, WEI Jingpeng, LV Yukun, LI Tianye. Precipitation σ Phase Evoluation and Mechanical Properties of (CoCrFeMnNi)97.02Mo2.98 High Entropy Alloy. Acta Metall Sin, 2020, 56(5): 769-775.

URL:     OR

Fig.1  SEM images of (CoCrFeMnNi)97.02Mo2.98 high entropy alloys after annealing at 700 ℃ (a), 800 ℃ (b), 900 ℃ (c) and 1000 ℃ (d)
Annealing temperaturePositionAtomic fraction / %
Table 1  EDS results of (CoCrFeMnNi)97.02Mo2.98 high entropy alloys after annealing at different temperatures
Fig.2  XRD spectra of (CoCrFeMnNi)97.02Mo2.98 high entropy alloys after annealing at different temperatures
Fig.3  Microhardness of (CoCrFeMnNi)97.02Mo2.98 high entropy alloys after annealing at different temperatures
Fig.4  The stress-strain curves of (CoCrFeMnNi)97.02-Mo2.98 high entropy alloys after annealing at different temperatures
Temperature / ℃σs / MPaσb / MPaδ / %
Table 2  Tensile properties of (CoCrFeMnNi)97.02Mo2.98 high entropy alloys after annealing at different temperatures
Fig.5  The tensile fracture morphologies of (CoCrFeMnNi)97.02Mo2.98 high entropy alloys after annealing at 700 ℃ (a), 800 ℃ (b), 900 ℃ (c) and 1000 ℃ (d)
1 Cantor B, Chang I T H, Knight P, et al. Microstructural development in equiatomic multicomponent alloys [J]. Mater Sci. Eng., 2004, A375: 213
2 Senkov O N, Woodward C, Miracle D B. Microstructure and properties of aluminum-containing refractory high-entropy alloys [J]. JOM, 2014, 66: 2030
doi: 10.1007/s11837-014-1066-0
3 Stepanov N D, Yurchenko N Y, Skibin D V, et al. Structure and mechanical properties of the AlCrxNbTiV (x=0, 0.5, 1, 1.5) high entropy alloys [J]. J. Alloys Compd., 2015, 652: 266
doi: 10.1016/j.jallcom.2015.08.224
4 Gludovatz B, Hohenwarter A, Catoor D, et al. A fracture-resistant high-entropy alloy for cryogenic applications [J]. Science, 2014, 345: 1153
doi: 10.1126/science.1254581 pmid: 25190791
5 Otto F, Dlouhy A, Somsen C, et al. The influences of temperature and microstructure on the tensile properties of a CoCrFeMnNi high-entropy alloy [J]. Acta Mater., 2013, 61: 5743
doi: 10.1016/j.actamat.2013.06.018
6 Gludovatz B, Hohenwarter A, Thurston K V S, et al. Exceptional damage-tolerance of a medium-entropy alloy CrCoNi at cryogenic temperatures [J]. Nat. Commun., 2016, 7: 10602
doi: 10.1038/ncomms10602 pmid: 26830651
7 Coury F G, Butler T, Chaput K, et al. Phase equilibria, mechanical properties and design of quaternary refractory high entropy alloys [J]. Mater. Des., 2018, 155: 244
doi: 10.1016/j.matdes.2018.06.003
8 Daoud H M, Manzoni A M, Wanderka N, et al. High-temperature tensile strength of Al10Co25Cr8Fe15Ni36Ti6 compositionally complex alloy (high-entropy alloy) [J]. JOM, 2015, 67: 2271
doi: 10.1007/s11837-015-1484-7
9 Chuang M H, Tsai M H, Wang W R, et al. Microstructure and wear behavior of AlxCo1.5CrFeNi1.5Tiy high-entropy alloys [J]. Acta Mater., 2011, 59: 6308
doi: 10.1016/j.actamat.2011.06.041
10 Yeh J W, Chen S K, Lin S J, et al. Nanostructured high-entropy alloys with multiple principal elements: novel alloy design concepts and outcomes [J]. Adv. Eng. Mater., 2004, 6: 299
11 Shahmir H, He J Y, Lu Z P, et al. Effect of annealing on mechanical properties of a nanocrystalline CoCrFeNiMn high-entropy alloy processed by high-pressure torsion [J]. Mater. Sci. Eng., 2016, A676: 294
12 Lu Z P, Lei Z F, Huang H D, et al. Deformation behavior and toughening of high-entropy alloys [J]. Acta Metall. Sin., 2018, 54: 1553
吕昭平, 雷智锋, 黄海龙等. 高熵合金的变形行为及强韧化 [J], 金属学报, 2018, 54: 1553
13 Rogal L, Kalita D, Tarasek A, et al. Effect of SiC nano-particles on microstructure and mechanical properties of the CoCrFeMnNi high entropy alloy [J]. J. Alloys Compd., 2017, 708: 344
14 Rogal L, Kalita D, Litynska-Dobrzynska L. CoCrFeMnNi high entropy alloy matrix nanocomposite with addition of Al2O3 [J]. Intermetallics, 2017, 86: 104
15 He J Y, Wang H, Huang H L, et al. A precipitation-hardened high-entropy alloy with outstanding tensile properties [J]. Acta Mater., 2016, 102: 187
16 Chen S T, Tang WY, Kuo Y F, et al. Microstructure and properties of age-hardenable AlxCrFe1.5MnNi0.5 alloys [J]. Mater. Sci. Eng., 2010, A527: 5818
17 Zhu J M, Zhang H F, Fu H M, et al. Microstructures and compressive properties of multicomponent AlCoCrCuFeNiMox alloys [J]. Mater. Sci. Eng., 2010, A527: 6975
18 Dong Y, Lu Y P, Kong J R, et al. Microstructure and mechanical properties of multi-component AlCrFeNiMox high-entropy alloys [J]. J. Alloys Compd., 2013, 573: 96
19 Stepanov N D, Shaysultanov D G, Ozerov M S, et al. Second phase formation in the CoCrFeNiMn high entropy alloy after recrystallization annealing [J]. Mater. Lett., 2016, 185: 1
20 Ming K S, Bi X F, Wang J. Precipitation strengthening of ductile Cr15Fe20Co35Ni20Mo10 alloys [J]. Scr. Mater., 2017, 137: 88
21 Liu W H, Lu Z P, He J Y, et al. Ductile CoCrFeNiMox high entropy alloys strengthened by hard intermetallic phases [J]. Acta Mater., 2016, 116: 332
22 Yao X F, Wei J P, Li T Y. Effects of Mo element on microstructure and mechanical properties of CoCrFeMnNi high entropy alloys [J]. IOP Conf. Series: Mater. Sci. Eng., 2019, 585: 012019
23 Li T Y, Yao X F, Lv Y K, et al. Effect of heat treatment on microstructure and properties of CoCrFeMnNi-5%Mo high entropy alloy [J]. J. Xi'an Technol. Univ., 2019, 39: 80
李田野, 姚小飞, 吕煜坤等. 热处理对CoCrFeMnNi-5%Mo高熵合金组织及性能的影响 [J]. 西安工业大学学报, 2019, 39: 80
24 Firstov S A, Rogul' T G, Krapivka N A, et al. Structural features and solid-solution hardening of high-entropy CrMnFeCoNi alloy [J]. Powder Metall. Met. Ceram., 2016, 55: 225
25 Qin G, Chen R R, Zheng H T, et al. Strengthening FCC-CoCrFeMnNi high entropy alloys by Mo addition [J]. J. Mater Sci. Technol., 2019, 35: 578
26 Fu J X, Cao C M, Tong W, et al. Effect of thermomechanical processing on microstructure and mechanical properties of CoCrFeNiMn high entropy alloy [J]. Trans. Nonferrous Met. Soc. China, 2018, 28: 931
27 Thurston K V S, Gludovatz B, Yu Q, et al. Temperature and load-ratio dependent fatigue-crack growth in the CrMnFeCoNi high-entropy alloy [J]. J. Alloys Compd., 2019, 794: 525
[1] LIU Jinlai, YE Lihua, ZHOU Yizhou, LI Jinguo, SUN Xiaofeng. Anisotropy of Elasticity of a Ni Base Single Crystal Superalloy[J]. 金属学报, 2020, 56(6): 855-862.
[2] HUANG Yuan, DU Jinlong, WANG Zumin. Progress in Research on the Alloying of Binary Immiscible Metals[J]. 金属学报, 2020, 56(6): 801-820.
[3] YU Jiaying, WANG Hua, ZHENG Weisen, HE Yanlin, WU Yurui, LI Lin. Effect of the Interface Microstructure of Hot-Dip Galvanizing High-Strength Automobile Steel on Its Tensile Fracture Behaviors[J]. 金属学报, 2020, 56(6): 863-873.
[4] GENG Yaoxiang, FAN Shimin, JIAN Jianglin, XU Shu, ZHANG Zhijie, JU Hongbo, YU Lihua, XU Junhua. Mechanical Properties of AlSiMg Alloy Specifically Designed for Selective Laser Melting[J]. 金属学报, 2020, 56(6): 821-830.
[5] HUANG Huogen, ZHANG Pengguo, ZHANG Pei, WANG Qinguo. Comparison of Glass Forming Ability Between U-Co and U-Fe Base Systems[J]. 金属学报, 2020, 56(6): 849-854.
[6] CHEN Wenxiong, HU Baojia, JIA Chunni, ZHENG Chengwu, LI Dianzhong. Post-Dynamic Softening of Austenite in a Ni-30%Fe Model Alloy After Hot Deformation[J]. 金属学报, 2020, 56(6): 874-884.
[7] LI Yuancai, JIANG Wugui, ZHOU Yu. Effect of Nanopores on Tensile Properties of Single Crystal/Polycrystalline Nickel Composites[J]. 金属学报, 2020, 56(5): 776-784.
[8] LIU Zhenpeng, YAN Zhiqiao, CHEN Feng, WANG Shuncheng, LONG Ying, WU Yixiong. Fabrication and Performance Characterization of Cu-10Sn-xNi Alloy for Diamond Tools[J]. 金属学报, 2020, 56(5): 760-768.
[9] WANG Xia, WANG Wei, YANG Guang, WANG Chao, REN Yuhang. Dimensional Effect on Thermo-Mechanical Evolution of Laser Depositing Thin-Walled Structure[J]. 金属学报, 2020, 56(5): 745-752.
[10] ZHAO Yanchun, MAO Xuejing, LI Wensheng, SUN Hao, LI Chunling, ZHAO Pengbiao, KOU Shengzhong, Liaw Peter K.. Microstructure and Corrosion Behavior of Fe-15Mn-5Si-14Cr-0.2C Amorphous Steel[J]. 金属学报, 2020, 56(5): 715-722.
[11] LIU Jizhao, HUANG Hefei, ZHU Zhenbo, LIU Awen, LI Yan. Numerical Simulation of Nanohardness in Hastelloy N Alloy After Xenon Ion Irradiation[J]. 金属学报, 2020, 56(5): 753-759.
[12] LIANG Mengchao, CHEN Liang, ZHAO Guoqun. Effects of Artificial Ageing on Mechanical Properties and Precipitation of 2A12 Al Sheet[J]. 金属学报, 2020, 56(5): 736-744.
[13] LI Meilin, LI Saiyi. Motion Characteristics of <c+a> Edge Dislocation on the Second-Order Pyramidal Plane in Magnesium Simulated by Molecular Dynamics[J]. 金属学报, 2020, 56(5): 795-800.
[14] LI Yuancai, JIANG Wugui, ZHOU Yu. Effect of Temperature on Mechanical Propertiesof Carbon Nanotubes-Reinforced Nickel Nano-Honeycombs[J]. 金属学报, 2020, 56(5): 785-794.
[15] LI Yizhuang,HUANG Mingxin. A Method to Calculate the Dislocation Density of a TWIP Steel Based on Neutron Diffraction and Synchrotron X-Ray Diffraction[J]. 金属学报, 2020, 56(4): 487-493.
No Suggested Reading articles found!