Effect of heat treatment on microstructure and properties of dual FCC-phase CoCrFeNiCu high entropy alloy

doi:10.13251/j.issn.0254-6051.2021.02.028

Abstract

Abstract: CoCrFeNiCu high entropy alloy was prepared by vacuum induction melting, and the effects of different annealing temperatures on microstructure and mechanical properties were studied. The results show that the as-cast CoCrFeNiCu alloy has a dual FCC-phase crystal structure, which are copper-rich phase and copper-dilute phase, respectively. The phase separation is gradually obvious as the heat treatment temperature increases. The microstructure of the as-cast alloy is a typical dendritic structure, and as the heat treatment temperature increases, the copper-rich phase increases, and the interdendritic region becomes wider, in which a large number of nanoparticles are precipitated. After heat treatment at 600 ℃, the yield and fracture strength of CoCrFeNiCu alloy are significantly improved, the yield strength reaches 233 MPa, and the fracture strength is close to 3 times of the as-cast alloy, however, the elongation of the alloy is basically unchanged.

Key words: high entropy alloy, heat treatment, dual FCC-phase, microstructure, mechanical properties

CLC Number:

TG142.1

Zhang Xiao, Liu Liang, Shang Jian, Zhao Zuofu, Zhang Yue, Qi Jingang, Wang Bing. Effect of heat treatment on microstructure and properties of dual FCC-phase CoCrFeNiCu high entropy alloy[J]. Heat Treatment of Metals, 2021, 46(2): 157-160.

References

[1] Cantor B,Chang I T H,Knight P,et al.Microstructural development in equiatomic multicomponent alloys[J].Materials Science &Engineering A,2004,375-377:213-218.
[2] 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].Advanced Engineering Materials,2004,6(5):299-303.
[3] Miracle D B,Senkov O N.A critical review of high entropy alloys (HEAs) and related concepts[J].Acta Materialia,2017,122:448-511.
[4] 刘亮,张越,赵作福,等.热处理对CoCrFeNiMo高熵合金组织与硬度的影响[J].金属热处理,2016,41(8):29-32.
Liu Liang,Zhang Yue,Zhao Zuofu,et al.Effect of heat treatment on microstructure and hardness of CoCrFeNiMo high entropy alloy[J].Heat Treatment of Metals,2016,41(8):29-32.
[5] 翟逸玥,寇生中,杨慧妮.Al_xCrFeNiMn高熵合金的组织和性能[J].金属热处理,2019,44(7):144-149.
Zhai Yiyue,Kou Shengzhong,Yang Huini.Microstructure and properties of Al_xCrFeNiMn high entropy alloys[J].Heat Treatment of Metals,2019,44(7):144-149.
[6] 王志新,周家臣,马明星,等.退火对AlCoCrFeMnTi高熵合金相组成与显微形貌的影响[J].金属热处理,2020,45(4):144-148.
Wang Zhixin,Zhou Jiachen,Ma Mingxing,et al.Effect of annealing on phase composition and morphology of AlCoCrFeMnTi high entropy alloy[J].Heat Treatment of Metals,2020,45(4):144-148.
[7] Gludovatz B,Hohenwarter A,Catoor D,et al.A fracture-resistant high-entropy alloy for cryogenic applications[J].Science,2014,345:1153-1158.
[8] Lin C M,Tsai H L.Effect of annealing treatment on microstructure and properties of high-entropy FeCoNiCrCu_0.5 alloy[J].Materials Chemistry and Physics,2011,128(1/2):50-56.
[9] Senkov O N,Wilks G B,Scott J M,et al.Mechanical properties of NbMoTaW and VNbMoTaW refractory high entropy alloys[J].Intermetallics,2011,19(5):698-706.
[10] Yang T,Xia S,Liu S,et al.Precipitation behavior of Al_xCoCrFeNi high entropy alloys under ion irradiation[J].Scientific Reports,2016(6):32146.
[11] Huang P K,Yeh J W,Shun T T,et al.Multi-principal-element alloys with improved oxidation and wear resistance for thermal spray coating[J].Advanced Engineering Materials,2004,6(1/2):74-78.
[12] Zhao Y,Wang X,Cao T,et al.Effect of grain size on the strain rate sensitivity of CoCrFeNi high-entropy alloy[J].Materials Science and Engineering A,2020,782:139281.
[13] Senkov O N,Wilks G B,Miracle D B,et al.Refractory high-entropy alloys[J].Intermetallics,2010,18(9):1758-1765.
[14] Nagase T,Anada S,Rack P D,et al.MeV electron-irradiation-induced structural change in the bcc phase of Zr-Hf-Nb alloy with an approximately equiatomic ratio[J].Intermetallics,2013,38:70-79.
[15] Bloomfield M E,Christofidou K A,Jones N G.Effect of Co on the phase stability of CrMnFeCo_xNi high entropy alloys following long-duration exposures at intermediate temperatures[J].Intermetallics,2019,114:106582.
[16] Deep Choudhuri,Shivakant Shukla,Philip A Jannotti,et al.Characterization of as-cast microstructural heterogeneities and damage mechanisms in eutectic AlCoCrFeNi_2.1 high entropy alloy[J].Materials Characterization,2019,158:109955.
[17] Yang T,Xia S,Liu S,et al.Effects of Al addition on microstructure and mechanical properties of Al_xCoCrFeNi high-entropy alloy[J].Materials Science and Engineering A,2015,648:15-22.
[18] 卢金斌,彭竹琴,马明星,等.Q235钢等离子熔覆CoCrCuFeMnNi高熵合金涂层[J].金属热处理,2016,41(4):51-54.
Lu Jinbin,Peng Zhuqin,Ma Mingxing,et al.CoCrCuFeMnNi high-entropy alloy coating prepared by plasma cladding on Q235 steel[J].Heat Treatment of Metals,2016,41(4):51-54.
[19] Park N,Watanabe I,Terada D,et al.Recrystallization behavior of CoCrCuFeNi high-entropy alloy[J].Metallurgical and Materials Transactions A,2015,46(4):1481-1487.
[20] Otto F,Yang Y,Bei H,et al.Relative effects of enthalpy and entropy on the phase stability of equiatomic high-entropy alloys[J].Acta Materialia,2013,61(7):2628-2638.
[21] Sang Hun Shim,Seung Min Oh,Lee Jeongkuk,et al.Nanoscale modulated structures by balanced distribution of atoms and mechanical/structural stabilities in CoCuFeMnNi high entropy alloys[J].Materials Science and Engineering A,2019,762:138120.
[22] 张越,刘亮,商剑.退火温度对CoCrFeNiAl高熵合金组织与性能的影响[J].金属热处理,2017,42(9):36-39.
Zhang Yue,Liu Liang,Shang Jian.Effect of annealing temperature on microstructure and properties of CoCrFeNiAl high entropy alloy[J].Heat Treatment of Metals,2017,42(9):36-39.
[23] Wani I S,Bhattacharjee T,Sheikh S,et al.Cold-rolling and recrystallization textures of a nano-lamellar AlCoCrFeNi_2.1 eutectic high entropy alloy[J].Intermetallics,2017,84:42-51.