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Acta Metall Sin  2020, Vol. 56 Issue (9): 1185-1194    DOI: 10.11900/0412.1961.2020.00026
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Microstructure Evolution of K4169 Alloy During Cyclic Loading
WU Yun1, LIU Yahui1, KANG Maodong1,2(), GAO Haiyan1,2, WANG Jun1,2, SUN Baode1,2
1 School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
2 Shanghai Key Laboratory of Advanced High-Temperature Materials and Precision Forming, Shanghai Jiao Tong University, Shanghai 200240, China
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Abstract  

K4169 nickel-based superalloy has been widely used to fabricate high-strength components in aircraft engine. When in service, especially affected by vibration and start-stop process, this alloy is inevitably affected by the external cyclic stress. Therefore, it is of great significance for researchers to understand the microstructure evolution in K4169 while cyclic loading. In the present study, the microstructure evolution of K4169 during cyclic loading has been examined and discussed in detail by using investment casting, cyclic loading and microstructure characterization methods. The cyclic loading test with stress amplitude of 380 MPa was carried out on a pull-push type fatigue machine at room temperature. The dependence of cycle times or fatigue life of specimens with different casting conditions on microporosity content has been discussed. Special emphases have been put on investigating the deformation and fracture characteristics of Laves and δ-Ni3Nb phases under the influence of microporosity. The results show that the cyclic life was mainly dominated by the content of microporosity. The crack initiation occurred mainly near the microporosity of the specimen surface. The specimen with high microporosity content exhibits the characteristic of complete brittle fracture, while the specimen with low microporosity content exhibits obvious transgranular fracture characteristics. In addition, the fracture of Laves phase was not apparently affected by cycle number. At the beginning of cyclic loading, the long-striped Laves phase near the microporosity was easy to crack, which became the sensitive area of crack growth, and extending in the manner of parallel secondary cracks. The δ-Ni3Nb plates near microporosity exhibited two obvious cyclic deformation and fracture characteristics depending on their arrangement (or growth orientation) relative to external loading axis: cracking along length direction (or denoted as branch cracking); and exhibiting slip lines and cracks on the surface of δ-Ni3Nb plates. At the initial stage of cyclic loading, δ-Ni3Nb plates were prone to crack along the length direction, while the surfaces of the δ-Ni3Nb plates far from microporosity appear the characteristics of slipping, bending and fracture in turn with the decrease of microporosity content or increase of cyclic cycles. Edge dislocations have been found within δ-Ni3Nb plates, indicating the transition from screw dislocations to edge dislocations under cyclic loading. Additionally, the twinning deformation of γ-Ni matrix during cyclic loading has been scrutinized through TEM and TKD analyses. The results have been linked to the evolutions of Laves and δ-Ni3Nb phases, i.e., the evolutions were influenced by the increase of strain localization around Laves and δ-Ni3Nb phases.

Key words:  K4169 superalloy      cyclic stress      microstructure evolution      Laves phase      δ-Ni3Nb phase     
Received:  17 January 2020     
ZTFLH:  TG132.3  
Fund: National Natural Science Foundation of China(51971142);National Science and Technology Major Project of China(2017-Ⅵ-0013-0085);Aeronautical Science Foundation of China(2018ZE57012);Startup Fund for Youngman Research at SJTU(18X100040027)
Corresponding Authors:  KANG Maodong     E-mail:  kangmd518@sjtu.edu.cn

Cite this article: 

WU Yun, LIU Yahui, KANG Maodong, GAO Haiyan, WANG Jun, SUN Baode. Microstructure Evolution of K4169 Alloy During Cyclic Loading. Acta Metall Sin, 2020, 56(9): 1185-1194.

URL: 

https://www.ams.org.cn/EN/10.11900/0412.1961.2020.00026     OR     https://www.ams.org.cn/EN/Y2020/V56/I9/1185

Fig.1  Dimension of the cyclic loading specimen (unit: mm)
Fig.2  Typical OM images containing microporosity of casted K4169 bars with hot spot diameters of 41.8 mm (a), 35.8 mm (b), 21.7 mm (c), 19.6 mm (d), 18.1 mm (e), 16.5 mm (f) and 11.8 mm (g) named specimens 1#~7#, respectively
Fig.3  Microstructure characteristics of K4169 alloy in standard heat treatment state
Fig.4  Distributions of Feret diameter of Laves phase in different specimens
Fig.5  Relationship between fatigue cycle (Nf) and volume fraction of microporosity (fv)
Fig.6  SEM images showing the fracture surfaces of low-cycle (394 cyc) (a~c) and high-cycle (5457 cyc) (d~f) specimens (PSBs—persistent slip bands)
Fig.7  SEM images of cyclic fractured Laves particle near the fracture surface in longitudinal section (a) and cyclic fractured Laves particle in fracture surface (b), and EDS results of the spot 1 in Fig.7a (c) and spot 2 in Fig.7b (d) (Inset in Fig.7a shows the secondary cracks)
Fig.8  SEM images of δ-Ni3Nb plates characterized by branch cracking and bending (a) and fractured δ-Ni3Nb plates induced by slip (b)
Fig.9  EBSD analyses of band contrast image of cyclic fractured Laves particle (a), inverse pole figure (IPF) image and 3D crystal orientation (insets) of the Laves particle (b) and local misorientation angle distribution within Ni-matrix nearby the Laves particle (c)
Fig.10  Deformation and fracture analyses of δ-Ni3Nb phase by SEM and TEM
Fig.11  TEM image (a) and TKD band contrast image (inset shows Kikuchi pattern of γ-Ni matrix) (b) showing twin related deformation characteristic of γ-Ni matrix after cyclic loading
[1] Mahadevan S, Nalawade S, Singh J B, et al. Evolution of δ phase microstructure in alloy 718 [A]. 7th International Symposium on Superalloy 718 and Derivatives [C]. Pittsburgh: The Minerals, Metals & Materials Society, 2010: 737
[2] Niang A, Viguier B, Lacaze J. Some features of anisothermal solid-state transformations in alloy 718 [J]. Mater. Charact., 2010, 61: 525
[3] Texier D, Gómez A C, Pierret S, et al. Microstructural features controlling the variability in low-cycle fatigue properties of alloy Inconel 718DA at intermediate temperature [J]. Metall. Mater. Trans., 2016, 47A: 1096
[4] Liu J H, Vanderesse N, Stinville J C, et al. In-plane and out-of-plane deformation at the sub-grain scale in polycrystalline materials assessed by confocal microscopy [J]. Acta Mater., 2019, 169: 260
doi: 10.1016/j.actamat.2019.03.001
[5] Xie X S, Dong J X, Fu S H, et al. Research and development of γ′′ and γ′ strengthened Ni-Fe base superalloy GH4169 [J]. Acta Metall. Sin., 2010, 46: 1289
doi: DOI: 10.3724/SP.J.1037.2010.00436
(谢锡善, 董建新, 付书红等. γ′′和γ′相强化的Ni-Fe基高温合金GH4169的研究与发展 [J]. 金属学报, 2010, 46: 1289)
doi: DOI: 10.3724/SP.J.1037.2010.00436
[6] Paulonis D F, Schirra J J. Alloy 718 at Pratt & Whitney-Historical perspective and future challenges [A]. 5th International Symposium on Superalloys 718, 625, 706, and Derivatives [C]. Pittsburgh: The Minerals, Metals & Materials Society, 2001: 13
[7] Schafrik R E, Ward D D, Groh J R. Application of alloy 718 in GE aircraft engines: Past, present and next five years [A]. 5th International Symposium on Superalloys 718, 625, 706, and Derivatives [C]. Pittsburgh: The Minerals, Metals & Materials Society, 2001: 1
[8] Trosch T, Strößner J, Völkl R, et al. Microstructure and mechanical properties of selective laser melted Inconel 718 compared to forging and casting [J]. Mater. Lett., 2016, 164: 428
[9] Praveen K V U, Singh V. Effect of heat treatment on Coffin-Manson relationship in LCF of superalloy IN718 [J]. Mater. Sci. Eng., 2008, A485: 352
[10] Xu J H, Huang Z W, Jiang L. Effect of heat treatment on low cycle fatigue of IN718 superalloy at the elevated temperatures [J]. Mater. Sci. Eng., 2017, A690: 137
[11] Slama C, Abdellaoui M. Structural characterization of the aged Inconel 718 [J]. J. Alloys Compd., 2000, 306: 277
doi: 10.1016/S0925-8388(00)00789-1
[12] Rao G A, Kumar M, Srinivas M, et al. Effect of standard heat treatment on the microstructure and mechanical properties of hot isostatically pressed superalloy Inconel 718 [J]. Mater. Sci. Eng., 2003, A355: 114
[13] Jeong D H, Choi M J, Goto M, et al. Effect of service exposure on fatigue crack propagation of Inconel 718 turbine disc material at elevated temperatures [J]. Mater. Charact., 2014, 95: 232
[14] Yeratapally S R, Glavicic M G, Hardy M, et al. Microstructure based fatigue life prediction framework for polycrystalline nickel-base superalloys with emphasis on the role played by twin boundaries in crack initiation [J]. Acta Mater., 2016, 107: 152
[15] Krueger D D, Antolovich S D, van Stone R H. Effects of grain size and precipitate size on the fatigue crack growth behavior of alloy 718 at 427 ℃ [J]. Metall. Trans., 1987, 18A: 1431
[16] Xiao L, Chen D L, Chaturvedi M C. Effect of boron on fatigue crack growth behavior in superalloy IN 718 at RT and 650 ℃ [J]. Mater. Sci. Eng., 2006, A428: 1
[17] Niang A, Huez J, Lacaze J, et al. Characterizing precipitation defects in nickel based 718 alloy [J]. Mater. Sci. Forum, 2010, 636-637: 517
[18] Dehmas M, Lacaze J, Niang A, et al. TEM study of high-temperature precipitation of delta phase in Inconel 718 alloy [J]. Adv. Mater. Sci. Eng., 2011, 2011: 940634
[19] Jiang H, Dong J X, Zhang M C, et al. Stress relaxation mechanism for typical nickel-based superalloys under service condition [J]. Acta Metall. Sin., 2019, 55: 1211
(江 河, 董建新, 张麦仓等. 服役条件下镍基高温合金应力松弛微观机制 [J]. 金属学报, 2019, 55: 1211)
[20] Liu Y H, Kang M D, Wu Y, et al. Effects of microporosity and precipitates on the cracking behavior in polycrystalline superalloy Inconel 718 [J]. Mater. Charact., 2017, 132: 175
[21] Sui S, Chen J, Fan E X, et al. The influence of Laves phases on the high-cycle fatigue behavior of laser additive manufactured Inconel 718 [J]. Mater. Sci. Eng., 2017, A695: 6
[22] Cao G X, Zhang M C, Dong J X, et al. Effects of Nb content variations on precipitates evolution of GH4169 ingots during their solidification and homogenization processes [J]. Rare Met. Mater. Eng., 2014, 43: 103
(曹国鑫, 张麦仓, 董建新等. Nb含量对GH4169合金钢锭凝固及均匀化过程相演化规律的影响 [J]. 稀有金属材料与工程, 2014, 43: 103)
[23] Pattnaik S, Karunakar D B, Jha P K. Developments in investment casting process—A review [J]. J. Mater. Process. Technol., 2012, 212: 2332
[24] Sigl K M, Hardin R A, Stephens R I, et al. Fatigue of 8630 cast steel in the presence of porosity [J]. Int. J. Cast Met. Res., 2004, 17: 130
[25] Overfelt R A, Sahai V, Ko Y K, et al. Porosity in cast equiaxed alloy 718 [A]. Superalloys 718, 625, 706, and Various Derivatives [C]. Warrendale: The Minerals, Metals & Materials Society, 1994: 189
[26] Flemings M C. Solidification Processing [M]. Weinheim: Wiley, 2006: 19
[27] Wu Y, Li S M, Kang M D, et al. Slip and fracture behavior of δ-Ni3Nb plates in a polycrystalline nickel-based superalloy during fatigue [J]. Scr. Mater., 2019, 171: 36
[28] Hidalgo R, Esnaola J A, Llavori I, et al. Fatigue life estimation of cast aluminium alloys considering the effect of porosity on initiation and propagation phases [J]. Int. J. Fatigue, 2019, 125: 468
[29] Lamm M, Singer R F. The effect of casting conditions on the high-cycle fatigue properties of the single-crystal nickel-base superalloy PWA 1483 [J]. Metall. Mater. Trans., 2007, 38A: 1177
[30] Boehlert C J, Li H, Wang L, et al. Slip system characterization of Inconel 718: Using in-situ scanning electron microscopy [J]. Adv. Mater. Process., 2010, 168(11): 41
[31] Sui S, Chen J, Ming X L, et al. The failure mechanism of 50% laser additive manufactured Inconel 718 and the deformation behavior of Laves phases during a tensile process [J]. Int. J. Adv. Manuf. Technol., 2017, 91: 2733
doi: 10.1007/s00170-016-9901-9
[32] Liu Y H, Wu Y, Kang M D, et al. Fracture mechanisms induced by microporosity and precipitates in isothermal fatigue of polycrystalline nickel based superalloy [J]. Mater. Sci. Eng., 2018, A736: 438
[33] Umakoshi Y, Hagihara K, Nakano T. Operative slip systems and anomalous strengthening in Ni3Nb single crystals with the D0astructure [J]. Intermetallics, 2001, 9: 955
[34] Kelly P M, Ren H P, Qiu D, et al. Identifying close-packed planes in complex crystal structures [J]. Acta Mater., 2010, 58: 3091
[35] Zhang H Y, Zhang S H, Cheng M, et al. Deformation characteristics of δ phase in the delta-processed Inconel 718 alloy [J]. Mater. Charact., 2010, 61: 49
[36] Sugimura H, Kaneno Y, Takasugi T. Alloying behavior of Ni3M-type compounds with D0a structure [J]. Mater. Trans., 2011, 52: 663
[37] Hagihara K, Nakano T, Umakoshi Y. Plastic deformation behaviour and operative slip systems in Ni3Nb single crystals [J]. Acta Mater., 2000, 48: 1469
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