Rapid Solidification Behavior and Microstructure Regulation of Ni43.5Co19Cr10Fe10Al15Ti2Mo0.5 Eutectic High-Entropy Alloy
Received date: 2024-08-14
Revised date: 2024-10-31
Online published: 2024-11-25
Supported by
National Natural Science Foundation of China(52474425)
Eutectic high-entropy alloys (EHEAs) have exhibited excellent mechanical properties. However, their rapid solidification behaviors during additive manufacturing processes still require further investigation. In the present study, Ni43.5Co19Cr10Fe10Al15Ti2Mo0.5 EHEA via copper mold casting and selective laser melting (SLM) were produced to study the influence of solidification conditions, such as cooling rate, on the phase area fraction, phase composition, grain morphology, and mechanical properties of the alloy. SEM, EBSD, TEM, and tensile testing were used to systematically analyze the solidification behaviors and mechanical properties of this EHEA. The center of the as-cast specimen has the lowest cooling rate, a large amount of fcc primary phase appears and forms equiaxed crystals, with a B2 phase area fraction of 16.9%. As the cooling rate increases, the amount of fcc primary phase decreases, and the area fraction of the B2 phase increases to 23.0% on the surface of the as-cast specimen. Meanwhile, the concentration of Al in the B2 phase of each region in the as-cast specimen is 23.2% (atomic fraction, the same below). However, with the continuous increase in the cooling rate, the area fraction of B2 phase tends to reach its lowest value in the SLM specimen, with only 15.8% in edge-on orientation, and the concentration of Al in the B2 phase decreases to 16.5%. The decrease in the area fraction of the B2 phase in SLM samples is due to solute trapping caused by the high cooling rate, resulting in the formation of a supersaturated solid solution and a reduction in the amount of liquid phase available for forming eutecticphase. In addition, during the SLM process, a high scanning rate results in a large temperature gradient, which promotes the formation of columnar crystals. Reducing the scanning rate to 500 mm/s causes a columnar-to-equiaxed transition due to the decrease in temperature gradient. The mechanical properties of the SLM specimens are superior to those of the as-cast specimens, with a room-temperature ultimate tensile strength of (1320.5 ± 4.5) MPa and a fracture elongation of (25.8 ± 2.2)%.
LU Jianlin , REN Huayong , XIE An , WANG Jiantong , HE Feng . Rapid Solidification Behavior and Microstructure Regulation of Ni43.5Co19Cr10Fe10Al15Ti2Mo0.5 Eutectic High-Entropy Alloy[J]. Acta Metall Sin, 2025 , 61(1) : 191 -202 . DOI: 10.11900/0412.1961.2024.00271
| 1 | Cantor B, Chang I T H, Knight P, et al. Microstructural development in equiatomic multicomponent alloys[J]. Mater. Sci. Eng., 2004, A375-377: 213 |
| 2 | Miracle D B, Senkov O N. A critical review of high entropy alloys and related concepts[J]. Acta Mater., 2017, 122: 448 |
| 3 | Wu Q F, He F, Li J J, et al. Phase-selective recrystallization makes eutectic high-entropy alloys ultra-ductile[J]. Nat. Commun., 2022, 13: 4697 |
| 4 | 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 |
| 5 | 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 |
| 6 | Jia Y H, Wang Z J, Wu Q F, et al. Enhancing the yield strength of Ni-Co-Cr-Fe-Al as-cast hypoeutectic high-entropy alloys by introducing γ′ precipitation[J]. Mater. Sci. Eng., 2022, A858: 144190 |
| 7 | Wu Q F, Wang Z J, Zheng T. A casting eutectic high entropy alloy with superior strength-ductility combination[J]. Mater. Lett., 2019, 253: 268 |
| 8 | Lu Y P, Gao X Z, Jiang L, et al. Directly cast bulk eutectic and near-eutectic high entropy alloys with balanced strength and ductility in a wide temperature range[J]. Acta Mater., 2017, 124: 143 |
| 9 | John R, Karati A, Joseph J, et al. Microstructure and mechanical properties of a high entropy alloy with a eutectic composition (AlCoCrFeNi2.1) synthesized by mechanical alloying and spark plasma sintering[J]. J. Alloys Compd., 2020, 835: 155424 |
| 10 | DebRoy T, Wei H L, Zuback J S, et al. Additive manufacturing of metallic components—Process, structure and properties[J]. Prog. Mater. Sci., 2018, 92: 112 |
| 11 | Herzog D, Seyda V, Wycisk E, et al. Additive manufacturing of metals[J]. Acta Mater., 2016, 117: 371 |
| 12 | Gorsse S, Hutchinson C, Gouné M, et al. Additive manufacturing of metals: A brief review of the characteristic microstructures and properties of steels, Ti-6Al-4V and high-entropy alloys[J]. Sci. Technol. Adv. Mater., 2017, 18: 584 |
| 13 | Sistla H R, Newkirk J W, Frank Liou F. Effect of Al/Ni ratio, heat treatment on phase transformations and microstructure of Al x FeCoCrNi2 - x (x = 0.3, 1) high entropy alloys[J]. Mater. Des., 2015, 81: 113 |
| 14 | Chai Z S, Zhou K X, Wu Q F, et al. Deformation behaviors of an additive-manufactured Ni32Co30Cr10Fe10Al18 eutectic high entropy alloy at ambient and elevated temperatures[J]. Acta Metall. Sin. (Engl. Lett.), 2022, 35: 1607 |
| 15 | Zhou K X, Li J J, Wu Q F, et al. Remelting induced fully-equiaxed microstructures with anomalous eutectics in the additive manufactured Ni32Co30Cr10Fe10Al18 eutectic high-entropy alloy[J]. Scr. Mater., 2021, 201: 113952 |
| 16 | Alamoudi M T, Wiezorek J M K. Probing effects of solute trapping on the mechanical properties of α-Al in rapidly solidified hypoeutectic Al-10at.%Cu after surface laser melting[J]. Mater. Sci. Eng., 2024, A890: 145934 |
| 17 | Wang Y M, Voisin T, McKeown J T, et al. Additively manufactured hierarchical stainless steels with high strength and ductility[J]. Nat. Mater., 2018, 17: 63 |
| 18 | Zhang K Q, Chen C Y, Xu S Z, et al. On the microstructure evolution and strengthening mechanism of GH4099 Ni-based superalloy fabricated by laser powder bed fusion[J]. Mater. Today Commun., 2024, 40: 109734 |
| 19 | Kim J G, Seol J B, Park J M, et al. Effects of cell network structure on the strength of additively manufactured stainless steels[J]. Met. Mater. Int., 2021, 27: 2614 |
| 20 | Li S H, Zhao Y K, Ramamurty U. Role of the solidification cells on the yield strength of the Al-Si-Mg alloy manufactured using laser powder bed fusion: A micropillar compression study[J]. Scr. Mater., 2023, 234: 115566 |
| 21 | Geng Z W, Chen C, Song M, et al. High strength Al0.7CoCrFeNi2.4 hypereutectic high entropy alloy fabricated by laser powder bed fusion via triple-nanoprecipitation[J]. J. Mater. Sci. Technol., 2024, 187: 141 |
| 22 | Kumar P, Huang S, Cook D H, et al. A strong fracture-resistant high-entropy alloy with nano-bridged honeycomb microstructure intrinsically toughened by 3D-printing[J]. Nat. Commun., 2024, 15: 841 |
| 23 | Trivedi R, Magnin P, Kurz W. Theory of eutectic growth under rapid solidification conditions[J]. Acta Metall., 1987, 35: 971 |
| 24 | Zimmermann M, Carrard M, Kurz W. Rapid solidification of Al-Cu eutectic alloy by laser remelting[J]. Acta Metall., 1989, 37: 3305 |
| 25 | Schempp P, Rethmeier M. Understanding grain refinement in aluminium welding: Henry Granjon Prize 2015 winner category B: Materials behaviour and weldability[J]. Weld. World, 2015, 59: 767 |
| 26 | Qi X, Takata N, Suzuki A, et al. Laser powder bed fusion of a near-eutectic Al-Fe binary alloy: Processing and microstructure[J]. Addit. Manuf., 2020, 35: 101308 |
| 27 | Kozie? T. Estimation of cooling rates in suction casting and copper-mould casting processes[J]. Arch. Metall. Mater., 2015, 60: 767 |
| 28 | Wang W L, Liu W Q, Yang X, et al. Multi-scale simulation of columnar-to-equiaxed transition during laser selective melting of rare earth magnesium alloy[J]. J. Mater. Sci. Technol., 2022, 119: 11 |
| 29 | Li Y L, Gu D D. Parametric analysis of thermal behavior during selective laser melting additive manufacturing of aluminum alloy powder[J]. Mater. Des., 2014, 63: 856 |
| 30 | Hornung J, Zikin A, Pichelbauer K, et al. Influence of cooling speed on the microstructure and wear behaviour of hypereutectic Fe-Cr-C hardfacings[J]. Mater. Sci. Eng., 2013, A576: 243 |
| 31 | Behera S K, Van Hoogstraten J, Rane K K, et al. The effect of cooling rate on the microstructure and physical properties of hypereutectic Al-Ce alloys[J]. Int. J. Met., 2024, 18: 6 |
| 32 | Ao X H, Xia H X, Liu J H, et al. Simulations of microstructure coupling with moving molten pool by selective laser melting using a cellular automaton[J]. Mater. Des., 2020, 185: 108230 |
| 33 | Antillon E A, Hareland C A, Voorhees P W. Solute trapping and solute drag during non-equilibrium solidification of Fe-Cr alloys[J]. Acta Mater., 2023, 248: 118769 |
| 34 | G?umann M, Henry S, Cléton F, et al. Epitaxial laser metal forming: Analysis of microstructure formation[J]. Mater. Sci. Eng., 1999, A271: 232 |
| 35 | Yang K V, Shi Y J, Palm F, et al. Columnar to equiaxed transition in Al-Mg(-Sc)-Zr alloys produced by selective laser melting[J]. Scr. Mater., 2018, 145: 113 |
| 36 | Li H G, Huang Y J, Jiang S S, et al. Columnar to equiaxed transition in additively manufactured CoCrFeMnNi high entropy alloy[J]. Mater. Des., 2021, 197: 109262 |
| 37 | Bermingham M J, StJohn D H, Krynen J, et al. Promoting the columnar to equiaxed transition and grain refinement of titanium alloys during additive manufacturing[J]. Acta Mater., 2019, 168: 261 |
| 38 | Kurz W, Bezen?on C, G?umann M. Columnar to equiaxed transition in solidification processing[J]. Sci. Technol. Adv. Mater., 2001, 2: 185 |
| 39 | Zhang G H, Lu X F, Li J Q, et al. In-situ grain structure control in directed energy deposition of Ti6Al4V[J]. Addit. Manuf., 2022, 55: 102865 |
| 40 | Tan X P, Kok Y, Tan Y J, et al. Graded microstructure and mechanical properties of additive manufactured Ti-6Al-4V via electron beam melting[J]. Acta Mater., 2015, 97: 1 |
| 41 | Liu Z Y, Zhao D D, Wang P, et al. Additive manufacturing of metals: Microstructure evolution and multistage control[J]. J. Mater. Sci. Technol., 2022, 100: 224 |
| 42 | Huang Y Z, Fleming T G, Clark S J, et al. Keyhole fluctuation and pore formation mechanisms during laser powder bed fusion additive manufacturing[J]. Nat. Commun., 2022, 13: 1170 |
| 43 | Wang L, Zhang Y M, Chia H Y, et al. Mechanism of keyhole pore formation in metal additive manufacturing[J]. npj Comput. Mater., 2022, 8: 22 |
| 44 | Liu J G, Wen P. Metal vaporization and its influence during laser powder bed fusion process[J]. Mater. Des., 2022, 215: 110505 |
| 45 | Guo L P, Wang H Z, Liu H J, et al. Understanding keyhole induced-porosities in laser powder bed fusion of aluminum and elimination strategy[J]. Int. J. Mach. Tools Manuf., 2023, 184: 103977 |
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