Effect of Cr/Mo/W on the Thermal Stability ofγ/γ′Coherent Microstructure in Ni-Based Superalloys
FAN Lihua, LI Jinlin, SUN Jiudong, LV Mengtian, WANG Qing(), DONG Chuang
Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China
Cite this article:
FAN Lihua, LI Jinlin, SUN Jiudong, LV Mengtian, WANG Qing, DONG Chuang. Effect of Cr/Mo/W on the Thermal Stability ofγ/γ′Coherent Microstructure in Ni-Based Superalloys. Acta Metall Sin, 2024, 60(4): 453-463.
In general, Ni-based superalloys exhibit high strength, good oxidation and corrosion resistance, and good creep-resistant properties at high temperatures (HTs) because of the coherent precipitation of cuboidal γ′ nanoparticles into a fcc-γ matrix induced by co-alloying of multiple elements. The present work designed a series of Ni-based superalloys based on the cluster composition formula [Al-Ni12](Al1(Ti, Nb, Ta)0.5(Cr, Mo, W)1.5), with S1-CM (Cr1.0Mo0.5), S2-CW (Cr1.0W0.5), and S3-CMW (Cr0.7Mo0.4W0.4), in which the amounts of Cr, Mo, and W were changed, whereas the contents of other elements were maintained. In addition, the effect of Cr, Mo, and W variation on the thermal stability of γ /γ′ coherent microstructure at HT in these superalloys was investigated. Alloy ingots were prepared by arc melting under an argon atmosphere, solid solutionized at 1300°C for 15 h, and then aged at 900°C for up to 500 h. Microstructural characterization and mechanical properties of these alloys in different aged states were studied by XRD, SEM, EPMA, TEM, Vickers hardness testing, and compressive testing.Result showed that all these three alloys have a high volume fraction (f > 70%) of γ′ particles uniformly distributed in the fcc-γ matrix. In particular, the γ′ particle shape is ellipsoidal in S1-CM and S2-CW alloys, whereas it is cuboidal in the S3-CMW alloy primarily because the latter has a more negative γ /γ′ lattice misfit (δ = -0.47%) than the former (δ = -0.25% to -0.33%). After aging for 500 h, the morphology of γ′ particles in each alloy has no evident change, and all of the particles have a slow coarsening rate (K = 10-18 nm3/s), in which the S3-CMW alloy exhibits the highest γ /γ′ microstructural stability (the coarsening rate of γ′ particles being K = 10.02 nm3/s). Moreover, the amount of second-phase precipitation near the grain boundaries in the S3-CMW alloy is less than that in the former two alloys. The microhardness test results showed that the microhardness of each alloy remains almost constant with aging time, thereby indicating the thermal stability of the coherent structure. In particular, the microhardness of the S3-CMW alloy is 397-418 HV, and the room-temperature compression yield strength is 818 MPa in the 200-h-aged state.
Fund: National Natural Science Foundation of China(91860108);Key Discipline and Major Project of Dalian Science and Technology Innovation Foundation(2020JJ25CY004)
Corresponding Authors:
WANG Qing, professor, Tel: (0411)84708615, E-mail: wangq@dlut.edu.cn
Table 1 Related data of the designed series of alloys, including cluster formula, alloy composition, γ′ particle size (r), γ′ volume fraction (f), microhardness (H) after aging at 900oC for 500 h, and lattice constant (aγ, aγ'), lattice misfit (δ) between γ and γ′ phase after aging at 900oC for 50 h
Fig.1 Equilibrium phase diagrams of the designed alloys calculated by Pandat software (Inset shows the typical peak-separation fitting of (200) plane in S1-CM alloy) (a) S1-CM (b) S2-CW (c) S3-CMW
Fig.2 OM image of the S3-CMW alloy after aging at 900oC for 50 h
Fig.3 XRD spectra of designed series of alloys after aging at 900oC for 50 h (Inset shows the corresponding local plots)
Fig.4 SEM images of designed alloys of S1-CM (a1, b1), S2-CW (a2, b2), and S3-CMW (a3, b3) after solid-solutionized at 1300oC for 15 h (a1-a3) and aged at 900oC for 50 h (b1-b3)
Fig.5 TEM dark-field images and selected area electron diffraction (SAED) patterns (insets) of 50 h-aged S1-CM (a) and S3-CMW (b) alloys
Fig.6 Microstructure evolutions of the alloys S1-CM (a1-c1), S2-CW (a2-c2), and S3-CMW (a3-c3) aged at 900oC for 100 h (a1-a3), 200 h (b1-b3), and 500 h (c1-c3)
Fig.7 Variations of particle size (a) and volume fraction (b) of γ′ precipitates with the aging time at 900oC in the designed alloys
Fig.8 SEM images of microstructures on the grain boundaries in 500 h-aged alloys at 900oC (a) S1-CM (b) S2-CW (c) S3-CMW
Fig.9 TEM bright-field images and the corresponding SAED patterns (insets) of precipitated phases on grain boundaries in 500 h-aged S3-CMW alloy at 900oC (a) μ phase (b) fcc phase
Fig.10 Back scattered electrons image (BEI) and corresponding elemental distribution maps on grain boundaries in 500 h-aged S3-CMW alloy at 900oC
Fig.11 Variations of microhardness of the 900oC-aged alloys with the aging time (a) and compressive true stress-strain curves of 200 h-aged alloys measured at room temperature (b)
Fig.12 Variations of the average particle size r3 with the aging time at 900oC in the series of alloys (K—coarsening rate constant, R2—coefficient of determination)
1
Phillips P J, Unocic R R, Mills M J. Low cycle fatigue of a polycrystalline Ni-based superalloy: Deformation substructure analysis[J]. Int. J. Fatigue, 2013, 57: 50
doi: 10.1016/j.ijfatigue.2012.11.008
2
Du B N, Yang J X, Cui C Y, et al. Effects of grain size on the high-cycle fatigue behavior of IN792 superalloy[J]. Mater. Des., 2015, 65: 57
doi: 10.1016/j.matdes.2014.08.059
3
Chiou M S, Jian S R, Yeh A C, et al. High temperature creep properties of directionally solidified CM-247LC Ni-based superalloy[J]. Mater. Sci. Eng., 2016, A655: 237
4
Jin T, Zhou Y Z, Wang X G, et al. Research process on microstructural stability and mechanical behavior of advanced Ni-based single crystal superalloys[J]. Acta Metall. Sin., 2015, 51: 1153
doi: 10.11900/0412.1961.2015.00429
Wang B, Zhang J, Pan X J, et al. Effects of W on microstructural stability of the third generation Ni-based single crystal superalloys[J]. Acta Metall. Sin., 2017, 53: 298
doi: 10.11900/0412.1961.2016.00379
Van Sluytman J S, Pollock T M. Optimal precipitate shapes in nickel-base γ-γ ′ alloys[J]. Acta Mater., 2012, 60: 1771
doi: 10.1016/j.actamat.2011.12.008
7
Xia W S, Zhao X B, Yue L, et al. A review of composition evolution in Ni-based single crystal superalloys[J]. J. Mater. Sci. Technol., 2020, 44: 76
doi: 10.1016/j.jmst.2020.01.026
8
Reed R C. The Superalloys: Fundamentals and Applications[M]. Cambridge: Cambridge University Press, 2006: 19
9
Yuan Y, Kawagishi K, Koizumi Y, et al. Creep deformation of a sixth generation Ni-base single crystal superalloy at 800oC[J]. Mater. Sci. Eng., 2014, A608: 95
10
Jácome L A, Nörtershäuser P, Heyer J K, et al. High-temperature and low-stress creep anisotropy of single-crystal superalloys[J]. Acta Mater., 2013, 61: 2926
doi: 10.1016/j.actamat.2013.01.052
11
Zhang Y, Wang Q, Dong H G, et al. Nickel-based single-crystal superalloys (Ni, Co)-Al-(Ta, Ti)-(Cr, Mo, W) designed by cluster-plus-glue-atom model and their 1000 h long-term ageing behavior at 900oC[J]. Acta Metall. Sin., 2018, 54: 591
Epishin A, Brückner U, Portella P D, et al. Influence of small rhenium additions on the lattice spacing of nickel solid solution[J]. Scr. Mater., 2003, 48: 455
doi: 10.1016/S1359-6462(02)00436-0
13
Heckl A, Neumeier S, Cenanovic S, et al. Reasons for the enhanced phase stability of Ru-containing nickel-based superalloys[J]. Acta Mater., 2011, 59: 6563
doi: 10.1016/j.actamat.2011.07.002
14
Tian S G, Wang M G, Yu H C, et al. Influence of element Re on lattice misfits and stress rupture properties of single crystal nickel-based superalloys[J]. Mater. Sci. Eng., 2010, A527: 4458
15
Kamara A B, Ardell A J, Wagner C N J. Lattice misfits in four binary Ni-Base γ /γ′ alloys at ambient and elevated temperatures[J]. Metall. Mater. Trans., 1996, 27A: 2888
16
MacKay R A, Nathal M V, Pearson D D. Influence of molybdenum on the creep properties of nickel-base superalloy single crystals[J]. Metall. Mater. Trans., 1990, 21A: 381
17
Nathal M V. Effect of initial gamma prime size on the elevated temperature creep properties of single crystal nickel base superalloys[J]. Metall. Mater. Trans., 1987, 18A: 1961
18
Pollock T M, Field R D. Dislocations and high-temperature plastic deformation of superalloy single crystals[J]. Dislocat. Solids, 2002, 11: 547
19
Liu X G, Wang L, Lou L H, et al. Effect of Mo addition on microstructural characteristics in a Re-containing single crystal superalloy[J]. J. Mater. Sci. Technol., 2015, 31: 143
doi: 10.1016/j.jmst.2013.12.019
20
Zhang J X, Wang J C, Harada H, et al. The effect of lattice misfit on the dislocation motion in superalloys during high-temperature low-stress creep[J]. Acta Mater., 2005, 53: 4623
doi: 10.1016/j.actamat.2005.06.013
21
Mughrabi H. The importance of sign and magnitude of γ/γ′ lattice misfit in superalloys—With special reference to the new γ′-hardened cobalt-base superalloys[J]. Acta Mater., 2014, 81: 21
doi: 10.1016/j.actamat.2014.08.005
22
Kawagishi K, Sato A, Harada H, et al. Oxidation resistant Ru containing Ni base single crystal superalloys[J]. Mater. Sci. Technol., 2009, 25: 271
doi: 10.1179/174328408X361517
23
Kawagishi K, Yeh A C, Yokokawa T, et al. Development of an oxidation-resistant high-strength sixth-generation single-crystal superalloy TMS-238[A]. Superalloys 2012[C]. Hoboken: Wiley, 2012: 189
24
Dubiel B, Indyka P, Kalemba-Rec I, et al. The influence of high temperature annealing and creep on the microstructure and chemical element distribution in the γ, γ ′ and TCP phases in single crystal Ni-base superalloy[J]. J. Alloys Compd., 2018, 731: 693
doi: 10.1016/j.jallcom.2017.10.076
25
Long H B, Mao S C, Liu Y N, et al. Structural evolution of topologically closed packed phase in a Ni-based single crystal superalloy[J]. Acta Mater., 2020, 185: 233
doi: 10.1016/j.actamat.2019.12.014
26
Liu G, Xiao X S, Véron M, et al. The nucleation and growth of η phase in nickel-based superalloy during long-term thermal exposure[J]. Acta Mater., 2020, 185: 493
doi: 10.1016/j.actamat.2019.12.038
27
Joubert J M. Crystal chemistry and Calphad modeling of the σ phase[J]. Prog. Mater. Sci., 2008, 53: 528
doi: 10.1016/j.pmatsci.2007.04.001
28
Matsugi K, Murata Y, Morinaga M, et al. An electronic approach to alloy design and its application to Ni-based single-crystal superalloys[J]. Mater. Sci. Eng., 1993, A172: 101
29
Morinaga M, Yukawa H. Recent progress in molecular orbital approach to alloy design[J]. Mater. Sci. Forum, 2004, 449-452: 37
doi: 10.4028/www.scientific.net/MSF.449-452
30
Morinaga M, Yukawa N, Adachi H, et al. New PHACOMP and its applications to alloy design[A]. Superalloys 1984[C]. Warrendale, PA: TMS, 1984: 523
31
Moniruzzaman M, Murata Y, Morinaga M, et al. Alloy design of Ni-based single crystal superalloys for the combination of strength and surface stability at elevated temperatures[J]. ISIJ Int., 2003, 43: 1244
doi: 10.2355/isijinternational.43.1244
32
Harada H, Murakami H. Design of Ni-base superalloys[A]. Computational Materials Design[M]. Berlin, Heidelberg: Springer, 1999: 39
33
Yamagata T, Harada H, Nakazawa S, et al. Alloy design for high strength nickel-base single crystal alloys[A]. Superalloys 1984[C]. Warrendale, PA: TMS, 1984: 157
34
Zhang, Y, Wang Q, Dong H G, et al. High-temperature structural stabilities of Ni-based single-crystal superalloys Ni-Co-Cr-Mo-W-Al-Ti-Ta with varying Co contents[J]. Acta Metall. Sin. (Eng. Lett.), 2018, 31: 127
35
Chen C, Wang Q, Dong C, et al. Composition rules of Ni-base single crystal superalloys and its influence on creep properties via a cluster formula approach[J]. Sci. Rep., 2020, 10: 21621
doi: 10.1038/s41598-020-78690-8
pmid: 33303877
36
Senkov O N, Miller J D, Miracle D B, et al. Accelerated exploration of multi-principal element alloys with solid solution phases[J]. Nat. Commun., 2015, 6: 6529
doi: 10.1038/ncomms7529
pmid: 25739749
37
Ye Y F, Wang Q, Lu J, et al. High-entropy alloy: Challenges and prospects[J]. Mater. Today, 2016, 19: 349
doi: 10.1016/j.mattod.2015.11.026
38
Miracle D B, Senkov O N. A critical review of high entropy alloys and related concepts[J]. Acta Mater., 2007, 122: 448
doi: 10.1016/j.actamat.2016.08.081
39
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
doi: 10.1002/adem.v6:5
40
Zhang Y, Zuo T T, Tang Z, et al. Microstructures and properties of high-entropy alloys[J]. Prog. Mater. Sci., 2014, 61: 1
doi: 10.1016/j.pmatsci.2013.10.001
41
Yang T, Zhao Y L, Tong Y, et al. Multicomponent intermetallic nanoparticles and superb mechanical behaviors of complex alloys[J]. Science, 2018, 362: 933
doi: 10.1126/science.aas8815
pmid: 30467166
42
Sun J D, Li J L, Yu H Y, et al. Microstructural stability of low-cost Ni-base superalloys with a high volume fraction of cuboidal γ' nanoprecipitates[J]. Mater. Sci. Eng., 2022, A833: 142550
43
Philippe T, Voorhees P W. Ostwald ripening in multicomponent alloys[J]. Acta Mater., 2013, 61: 4237
doi: 10.1016/j.actamat.2013.03.049
44
Orthacker A, Haberfehlner G, Taendl J, et al. Diffusion-defining atomic-scale spinodal decomposition within nanoprecipitates[J]. Nat. Mater., 2018, 17: 1101
doi: 10.1038/s41563-018-0209-z
pmid: 30420670
45
Zhuang X L, Lu S, Li L F, et al. Microstructures and properties of a novel γ ′-strengthened multi-component CoNi-based wrought superalloy designed by CALPHAD method[J]. Mater. Sci. Eng., 2020, A780: 139219
46
Gao Y H, Liu G, Sun J. Recent progress in high-temperature resistant aluminum-based alloys: Microstructural design and precipitation strategy[J]. Acta Metall. Sin., 2021, 57: 129
doi: 10.11900/0412.1961.2020.00347
Wang W Z, Jin T, Liu J L, et al. Role of Re and Co on microstructures and γ' coarsening in single crystal superalloys[J]. Mater. Sci. Eng., 2008, A479: 148
