Microstructure and Mechanical Properties of As-Cast and Laser Powder Bed Fused AlCoCrFeNi2.1 Eutectic High-Entropy Alloy

doi:10.11900/0412.1961.2023.00301

Acta Metall Sin

2024, Vol. 60

Issue (11): 1461-1470 DOI: 10.11900/0412.1961.2023.00301

Research paper

Current Issue | Archive | Adv Search

Microstructure and Mechanical Properties of As-Cast and Laser Powder Bed Fused AlCoCrFeNi_2.1 Eutectic High-Entropy Alloy

TANG Xu¹^,², ZHANG Hao¹(

), XUE Peng¹, WU Lihui¹, LIU Fengchao¹, ZHU Zhengwang¹, NI Dingrui¹(

), XIAO Bolv¹, MA Zongyi¹

1 Shi -changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
2 School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China

Cite this article:

TANG Xu, ZHANG Hao, XUE Peng, WU Lihui, LIU Fengchao, ZHU Zhengwang, NI Dingrui, XIAO Bolv, MA Zongyi. Microstructure and Mechanical Properties of As-Cast and Laser Powder Bed Fused AlCoCrFeNi_2.1 Eutectic High-Entropy Alloy. Acta Metall Sin, 2024, 60(11): 1461-1470.

Download:

HTML

PDF(4942KB)
Export: BibTeX | EndNote (RIS)

Abstract

Eutectic high-entropy alloys (EHEAs), as a typical kind of in situ composite, have become a potential alternative for conventional alloys because of their advantages in high-entropy alloys and eutectic alloys. Casting is the conventional preparation method of EHEAs, which is a well-established process with low production efficiency. Laser powder bed fusion (LPBF) is an economical and effective preparation technology that provides a novel way to directly form fine and complex EHEA components. In this study, considering the different application requirements and technical characteristics, AlCoCrFeNi_2.1 EHEA was prepared by vacuum induction melting and LPBF, respectively. The effect of the preparation process on the microstructure of the alloy was investigated. In addition, tensile properties of the samples at 20, 500, and 700°C were investigated. Results showed that as-cast and LPBF-formed AlCoCrFeNi_2.1 exhibited a eutectic structure composed of alternating fcc and bcc/B2 phases. The high heating and cooling rates during the LPBF process were conducive to the formation of ultrafine and uniform eutectic lamellae, which significantly reduced element segregation. During tensile deformation at room temperature, considering the strong phase boundary strengthening and dual-phase synergistic deformation, the ultimate tensile strength of the LPBF-formed sample was enhanced by about 28% compared with that of the as-cast sample, and a satisfactory elongation of 10% was obtained. At 500°C, the mechanical properties of the as-cast and LPBF-formed samples decreased probably because of the severe phase transformation in the alloy. When the testing temperature was increased to 700°C, the mechanical properties of the as-cast sample continued to decrease. The LPBF-formed samples showed a low tensile strength and superior elongation that should be attributed to the eutectic lamellae sliding along the phase boundaries at high temperatures. Meanwhile, the fracture mechanism of the LPBF-formed sample was dominated by ductile fracture. This work could provide a theoretical basis for the optimization of the microstructure and mechanical properties of EHEAs, thereby promoting their industrial application.

Key words: eutectic high-entropy alloy laser powder bed fusion microstructure mechanical property fracture mechanism

Received: 14 July 2023

ZTFLH:

TG132.32

Fund: National Natural Science Foundation of China(U21A2043);Youth Innovation Promotion Association, CAS(2022191);Bintech-IMR Research and Development Program(GYY-JSBU-2022-010)

Corresponding Authors: NI Dingrui, professor, Tel: (024)23971752, E-mail: drni@imr.ac.cn;

	Service

	E-mail this article
	Add to citation manager
	E-mail Alert
	RSS
	（）
	Articles by authors
	TANG Xu
	ZHANG Hao
	XUE Peng
	WU Lihui
	LIU Fengchao
	ZHU Zhengwang
	NI Dingrui
	XIAO Bolv
	MA Zongyi

URL:

https://www.ams.org.cn/EN/10.11900/0412.1961.2023.00301 OR https://www.ams.org.cn/EN/Y2024/V60/I11/1461

Fig.1 SEM image (a) and size distribution (b) of the AlCoCrFeNi_2.1 powders

Fig.2 Schematic illustration of the tensile specimens (unit: mm)

Fig.3 OM images of microstructures of as-cast sample (a), Y-Z plane (b), and X-Y plane (c) of laser powder bed fusion (LPBF)-formed AlCoCrFeNi_2.1 sample (X—horizontal direction, Y—scanning direction, Z—construction direction)

Fig.4 XRD spectra of as-cast and LPBF-formed AlCoCrFeNi_2.1 samples

Fig.5 SEM images of as-cast sample (a), Y-Z plane (b), and X-Y plane (c) of LPBF-formed sample

Fig.6 STEM dark field images, selected area electron diffraction patterns, and EDS maps of as-cast (a) and LPBF-formed (b) AlCoCrFeNi_2.1 samples

Fig.7 Tensile stress-strain curves of as-cast (a) and LPBF-formed (b) AlCoCrFeNi_2.1 samples at different temperatures, and variations of ultimate tensile strength (c) and elongation (d) with temperature

Fig.8 Phase diagram of AlCoCrFeNi_2.1 alloy (Thermo-Calc)

Fig.9 SEM images of fracture surfaces of as-cast (a-c) and LPBF-formed (d-f) AlCoCrFeNi_2.1 samples after tensile fracture at 20℃ (a, d), 500℃ (b, e), and 700℃ (c, f)

Fig.10 SEM images of fracture longtudinal sections of as-cast (a, c, e) and LPBF-formed (b, d, f) AlCoCrFeNi_2.1 samples after tensile fracture at 20^oC (a, b), 500^oC (c, d), and 700^oC (e, f)

1	Leong Z, Ramamurty U, Tan T L. Microstructural and compositional design principles for Mo-V-Nb-Ti-Zr multi-principal element alloys: A high-throughput first-principles study [J]. Acta Mater., 2021, 213: 116958
2	Kies F, Wu X X, Hallstedt B, et al. Enhanced precipitation strengthening of multi-principal element alloys by κ- and B2-phases [J]. Mater. Des., 2021, 198: 109315
3	Chen Y J, Chen D K, An X H, et al. Unraveling dual phase transformations in a CrCoNi medium-entropy alloy [J]. Acta Mater., 2021, 215: 117112
4	Kautz E J, Schreiber D K, Devaraj A, et al. Mechanistic insights into selective oxidation and corrosion of multi-principal element alloys from high resolution and in situ microscopy [J]. Materialia, 2021, 18: 101148
5	Ding J L, Xu H J, Li X, et al. The similarity of elements in multi-principle element alloys based on a new criterion for phase constitution [J]. Mater. Des., 2021, 207: 109849
6	Vikram R J, Murty B S, Fabijanic D, et al. Insights into micro-mechanical response and texture of the additively manufactured eutectic high entropy alloy AlCoCrFeNi_2.1 [J]. J. Alloys Compd., 2020, 827: 154034
7	Das S, Robi P S. Processing and characterization of W₂₃Mo₂₃V₁₇Cr₈-Ta₇Fe₂₂ and WMoVCrTa refractory high entropy alloys [J]. Int. J. Refract. Met. Hard Mater., 2021, 100: 105656
8	Dada M, Popoola P, Mathe N, et al. The comparative study of the microstructural and corrosion behaviour of laser-deposited high entropy alloys [J]. J. Alloys Compd., 2021, 866: 158777
9	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
10	Rogal Ł. Semi-solid processing of the CoCrCuFeNi high entropy alloy [J]. Mater. Des., 2017, 119: 406
11	Tang Z, Senkov O N, Parish C M, et al. Tensile ductility of an AlCoCrFeNi multi-phase high-entropy alloy through hot isostatic pressing (HIP) and homogenization [J]. Mater. Sci. Eng., 2015, A647: 229
12	Wang M L, Cui H Z, Zhao Y Q, et al. A simple strategy for fabrication of an FCC-based complex concentrated alloy coating with hierarchical nanoprecipitates and enhanced mechanical properties [J]. Mater. Des., 2019, 180: 107893
13	Huang H L, Wu Y, He J Y, et al. Phase-transformation ductilization of brittle high-entropy alloys via metastability engineering [J]. Adv. Mater., 2017, 29: 1701678
14	Li R D, Niu P D, Yuan T C, et al. Selective laser melting of an equiatomic CoCrFeMnNi high-entropy alloy: Processability, non-equilibrium microstructure and mechanical property [J]. J. Alloys Compd., 2018, 746: 125
15	Wang Q, Ma Y, Jiang B B, et al. A cuboidal B2 nanoprecipitation-enhanced body-centered-cubic alloy Al_0.7CoCrFe₂Ni with prominent tensile properties [J]. Scr. Mater., 2016, 120: 85
16	Lu Y P, Dong Y, Guo S, et al. A promising new class of high-temperature alloys: Eutectic high-entropy alloys [J]. Sci. Rep., 2014, 4: 6200 doi: 10.1038/srep06200 pmid: 25160691
17	Lu Y P, Dong Y, Jiang H, et al. Promising properties and future trend of eutectic high entropy alloys [J]. Scr. Mater., 2020, 187: 202
18	Shi P J, Ren W L, Zheng T X, et al. Enhanced strength-ductility synergy in ultrafine-grained eutectic high-entropy alloys by inheriting microstructural lamellae [J]. Nat. Commun., 2019, 10: 489 doi: 10.1038/s41467-019-08460-2 pmid: 30700708
19	Nassar A, Mullis A, Cochrane R, et al. Rapid solidification of AlCoCrFeNi_2.1 high-entropy alloy [J]. J. Alloys Compd., 2022, 900: 163350
20	Wang J T, Long Z P, Jiang P F, et al. Microstructure, crystallographic orientation and mechanical property in AlCoCrFeNi_2.1 eutectic high-entropy alloy under magnetic field-assisted directional solidification [J]. Metall. Mater. Trans., 2020, 51A: 3504
21	Gao X Z, Lu Y P, Zhang B, et al. Microstructural origins of high strength and high ductility in an AlCoCrFeNi_2.1 eutectic high-entropy alloy [J]. Acta Mater., 2017, 141: 59
22	Shi P J, Zhong Y B, Li Y, et al. Multistage work hardening assisted by multi-type twinning in ultrafine-grained heterostructural eutectic high-entropy alloys [J]. Mater. Today, 2020, 41: 62
23	Xiong T, Zheng S J, Pang J Y, et al. High-strength and high-ductility AlCoCrFeNi_2.1 eutectic high-entropy alloy achieved via precipitation strengthening in a heterogeneous structure [J]. Scr. Mater., 2020, 186: 336
24	Wani I S, Bhattacharjee T, Sheikh S, et al. Tailoring nanostructures and mechanical properties of AlCoCrFeNi_2.1 eutectic high entropy alloy using thermo-mechanical processing [J]. Mater. Sci. Eng., 2016, A675: 99
25	Brif Y, Thomas M, Todd I. The use of high-entropy alloys in additive manufacturing [J]. Scr. Mater., 2015, 99: 93
26	Tang X, Zhang S, Zhang C H, et al. Optimization of laser energy density and scanning strategy on the forming quality of 24CrNiMo low alloy steel manufactured by SLM [J]. Mater. Charact., 2020, 170: 110718
27	Guo Y N, Su H J, Zhou H T, et al. Unique strength-ductility balance of AlCoCrFeNi_2.1 eutectic high entropy alloy with ultra-fine duplex microstructure prepared by selective laser melting [J]. J. Mater. Sci. Technol., 2022, 111: 298
28	He L, Wu S W, Dong A P, et al. Selective laser melting of dense and crack-free AlCoCrFeNi_2.1 eutectic high entropy alloy: Synergizing strength and ductility [J]. J. Mater. Sci. Technol., 2022, 117: 133
29	Ren J, Zhang Y, Zhao D X, et al. Strong yet ductile nanolamellar high-entropy alloys by additive manufacturing [J]. Nature, 2022, 608: 62
30	Chen X S, Kong J, Li J L, et al. High-strength AlCoCrFeNi_2.1 eutectic high entropy alloy with ultrafine lamella structure via additive manufacturing [J]. Mater. Sci. Eng., 2022, A854: 143816
31	Miao J W, Wang M L, Zhang A J, et al. Tribological properties and wear mechanism of AlCr_1.3TiNi₂ eutectic high-entropy alloy at elevated temperature [J]. Acta Metall. Sin., 2023, 59: 267
	苗军伟, 王明亮, 张爱军等. AlCr_1.3TiNi₂共晶高熵合金的高温摩擦学性能及磨损机理 [J]. 金属学报, 2023, 59: 267 doi: 10.11900/0412.1961.2021.00589
32	Tsai K Y, Tsai M H, Yeh J W. Sluggish diffusion in Co-Cr-Fe-Mn-Ni high-entropy alloys [J]. Acta Mater., 2013, 61: 4887
33	Tang X, Zhang H, Zhu Z W, et al. Dual-phase synergistic deformation characteristics and strengthening mechanism of AlCoCrFeNi_2.1 eutectic high entropy alloy fabricated by laser powder bed fusion [J]. J. Mater. Sci. Technol., 2023, 150: 75
34	Mullins W W, Sekerka R F. Stability of a planar interface during solidification of a dilute binary alloy [J]. J. Appl. Phys., 1964, 35: 444
35	Xiong M X, Liew J Y R. Mechanical properties of heat-treated high tensile structural steel at elevated temperatures [J]. Thin-Wall. Struct., 2016, 98: 169
36	Qiang X H, Bijlaard F, Kolstein H. Dependence of mechanical properties of high strength steel S690 on elevated temperatures [J]. Constr. Build. Mater., 2012, 30: 73
37	Jiang J, Bao W, Peng Z Y, et al. Experimental investigation on mechanical behaviours of TMCP high strength steel [J]. Constr. Build. Mater., 2019, 200: 664 doi: 10.1016/j.conbuildmat.2018.12.130
38	Shaheen M A, Presswood R, Afshan S. Application of machine learning to predict the mechanical properties of high strength steel at elevated temperatures based on the chemical composition [J]. Structures, 2023, 52: 17
39	Yakel H L. Atom distribution in sigma phases. Ⅰ. Fe and Cr atom distribution in a binary sigma phase equilibrated at 1063, 1013 and 923K [J]. Acta Cryst., 1983, 39B: 20
40	Chinese Society of Metals High Temperature Materials Branch. China Superalloys Handbook [M]. Beijing: Standards Press of China, 2012: 30
	中国金属学会高温材料分会. 中国高温合金手册 [M]. 北京: 中国标准出版社, 2012: 30

[1]	WANG Lin, WEI Chen, WANG Lei, WANG Jun, LI Jinshan. Simulation of Core-Shell Structure Evolution of Cu-Co Immiscible Alloys[J]. 金属学报, 2024, 60(9): 1239-1249.
[2]	GONG Weijia, LIANG Senmao, ZHANG Jingyi, LI Shilei, SUN Yong, LI Zhongkui, LI Jinshan. Effect of Cooling Rate on Hydride Precipitation in Zirconium Alloys[J]. 金属学报, 2024, 60(9): 1155-1164.
[3]	ZHANG Qiankun, HU Xiaofeng, JIANG Haichang, RONG Lijian. Effect of Si on Microstructure and Mechanical Properties of a 9Cr Ferritic/Martensitic Steel[J]. 金属学报, 2024, 60(9): 1200-1212.
[4]	ZHOU Mu, WANG Qian, WANG Yanxu, ZHAI Zirong, HE Lunhua, LI Bing, MA Yingjie, LEI Jiafeng, YANG Rui. Effect of Prewelding Pretreatment on Welding Residual Stress of Titanium Alloy Thick Plate[J]. 金属学报, 2024, 60(8): 1064-1078.
[5]	CHEN Cheng, YANG Guangyu, JIN Menghui, WANG Qiang, TANG Xin, CHENG Huimin, JIE Wanqi. Effect of the Mold Positive and Negative Rotation on the Microstructure and Room-Temperature Mechanical Properties of K4169 Superalloy[J]. 金属学报, 2024, 60(7): 926-936.
[6]	MENG Yujia, XI Tong, YANG Chunguang, ZHAO Jinlong, ZHANG Xinrui, YU Yingjie, YANG Ke. Effect of Gallium Addition on Mechanical and Antibacterial Properties of 304L Stainless Steel[J]. 金属学报, 2024, 60(7): 890-900.
[7]	WANG Lijia, HU Li, MIAO Tianhu, ZHOU Tao, HE Qubo, LIU Xiangguo. Effect of Pre-Deformation on Mechanical Behavior and Microstructure Evolution of AZ31 Mg Alloy Sheet with Bimodal Non-Basal Texture at Room Temperature[J]. 金属学报, 2024, 60(7): 881-889.
[8]	XU Renjie, TU Xin, HU Bin, LUO Haiwen. Microstructure and Mechanical Properties of Cu-V Dual Alloyed 3Mn Steel[J]. 金属学报, 2024, 60(6): 817-825.
[9]	LIU Jinlai, SUN Jingxia, MENG Jie, LI Jinguo. Microstructural Stability and Stress Rupture Properties of a Third-Generation Ni Base Single Crystal Supalloy[J]. 金属学报, 2024, 60(6): 770-776.
[10]	XIE Liwen, ZHANG Lilong, LIU Yanyan, ZHANG Mingyang, WANG Shaogang, JIAO Da, LIU Zengqian, ZHANG Zhefeng. Fabrication and Mechanical Properties of Bioinspired Mg-Based Composites Reinforced by Stainless Steel Fibers[J]. 金属学报, 2024, 60(6): 760-769.
[11]	ZHANG Jingwen, YU Liming, LIU Chenxi, DING Ran, LIU Yongchang. Synergistic Strengthening of High-Cr Martensitic Heat-Resistant Steel and Application of Thermo-Mechanical Treatments[J]. 金属学报, 2024, 60(6): 713-730.
[12]	WANG Feng, BAI Shengwei, WANG Zhi, DU Xudong, ZHOU Le, MAO Pingli, WEI Ziqi, LI Jinwei. Research Progress on Hot Tearing Behavior of Mg-Zn Series Alloys[J]. 金属学报, 2024, 60(6): 743-759.
[13]	WANG Zheng, WANG Zhenyu, WANG Aiying, YANG Wei, KE Peiling. Influence of Micro-Arc Oxidation Time on Structure and Properties of MAO/Cr Composite Coatings[J]. 金属学报, 2024, 60(5): 691-698.
[14]	LI Kangjie, SUN Zeyu, HE Bei, TIAN Xiangjun. Microstructure and Hardness of Al-Cu-Li Alloy Fabricated by Arc Additive Manufacturing Based on In Situ Metallurgy of Molten Pool[J]. 金属学报, 2024, 60(5): 661-669.
[15]	LIU Zhongwu, ZHOU Bang, LIAO Xuefeng, HE Jiayi. Research Status and Future Development of (Ce, La, Y)-Fe-B Permanent Magnets Based on Full High-Abundance Rare Earth Elements[J]. 金属学报, 2024, 60(5): 585-604.

No Suggested Reading articles found!

Viewed

Full text

Abstract

Cited

Shared

Discussed