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Acta Metall Sin  2018, Vol. 54 Issue (4): 566-574    DOI: 10.11900/0412.1961.2017.00240
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Oxidation and Microstructure Evolution of CoAl Coating on Directionally Solidified Ni-Based Superalloys DZ466
Weipeng REN1(), Qing LI1, Qiang HUANG1, Chengbo XIAO1, Limin HE2
1 Science and Technology on Advanced High Temperature Structural Materials Laboratory, Beijing Institute of Aeronautical Materials, Beijing 100095, China
2 Aviation Key Laboratory of Science and Technology on Advanced Corrosion and Protection for Aviation Materials, Beijing Institute of Aeronautical Materials, Beijing 100095, China
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Aluminide coatings are widely employed to protect internal cooling channels of high grades blades and buckets in gas turbines have always been in severe conditions including high temperature oxidation and hot corrosion. There is a major concern for the application of aluminide coatings that refer to the inter-diffusion between aluminide coating and superalloy substrate at high temperatures. Diffusion of Al from the coating to the underlying substrate usually leads to depletion of Al in the coating, resulting in inferior oxidation resistance of the coating. Accordingly, Ni declines to diffuse counter currently from the substrate into the coating, as well as other refractory elements, such as Cr, Mo and W etc.. The inter-diffusion between aluminide coating and superalloy substrate results in degradation or various evolution behaviors of aluminide coatings, in other words, substrate composition significantly affects the properties of aluminide coatings. CoAl coating was prepared on directionally solidified superalloy DZ466 by low pressure chemical vapour deposition (LP-CVD). Oxidation behavior and microstructure evolution of CoAl coating was investigated during long term (about 5000 h) exposure at 900 ℃. Results suggested that, high concentration of aluminum did help to form Al2O3 on the surface of coating, improving oxidation resistance of DZ466 at 900 ℃. Evolution of matrix phase and precipitates in the CoAl coating during exposure was displayed, β-NiAl/CoAl phase in the coating transformed gradually to γ'-Ni3Al phase, higher transformation rate for the γ' phase closed to the substrate due to the diffusion between the coating and the sub strate superalloy. During exposure, α-Cr phase precipitated in the middle layer, which inclined to form close to carbides and grow by consuming them. Needle like TCP phase (μ phase) grew in the inner layer that arranged in order, which was due to the cubic microstructure of γ/γ'. Heredity-effect was in company with the precipitates evolution.

Key words:  Ni-based superalloy      DZ466      CoAl      coating      oxidation     
Received:  16 June 2017     
ZTFLH:  TG174.4  
Fund: Supported by National Science and Technology Major Project of China (No.2012ZX04007-021-03)

Cite this article: 

Weipeng REN, Qing LI, Qiang HUANG, Chengbo XIAO, Limin HE. Oxidation and Microstructure Evolution of CoAl Coating on Directionally Solidified Ni-Based Superalloys DZ466. Acta Metall Sin, 2018, 54(4): 566-574.

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Fig.1  Oxidation kinetics curves of DZ466 and DZ466-CoAl for exposure at 900 ℃

(a) mass gain vs time t

(b) curves of mass gain per aera Δm/A by t1/2 (c) mass change vs t

Fig.2  Surface morphologies of DZ466-CoAl as-deposited (a) and exposure at 900 ℃ for 500 h (b), 1000 h (c) and 5029 h (d)
Fig.3  XRD spectra of DZ466-CoAl as-deposited (a) and exposure at 900 ℃ for 500 h (b)
Fig.4  Surface SEM images of DZ466-CoAl as-deposited (a), and exposured at 900 ℃ for 500 h (b~d) and 5029 h (e), and EDS of the square aera in Fig.4d (f) (Figs.4c and d show the enlarged view of zones I and II in Fig.4b, respecticvely)
Fig.5  Cross-sectional SEM images of DZ466-CoAl as-deposited (a) and exposure at 900 ℃ for 5029 h (b) (Inset is the high magnification of the corresponding area tied up by the rectangle)
Phase Al Co Ni Ti Cr Mo W Hf Ta
β-NiAl/CoAl 27.39 7.98 61.69 0.56 0.78 - - - -
β 19.21 7.56 63.26 0.88 5.99 - - - -
MC - 2.80 5.37 2.93 1.09 - - 48.99 37.26
M6C - 7.55 10.27 0.68 13.56 7.80 46.37 - 12.88
M23C6 2.69 12.56 23.46 3.78 32.91 6.99 16.34 - -
μ 1.57 6.99 25.37 0.87 10.35 8.21 35.25 - 10.17
Table 1  Composition of phases in Fig.5(mass fraction / %)
Fig.6  Kinetics curve of γ' in the aluminide coating at 900 ℃
Fig.7  Schematic for evolution of CoAl coating[18]

(a) as deposited (b) exposure for short term (c) exposure for long term

[1] Liu L, Yang F, Wu Y.Preparation of Si-modified aluminide coating by CVD process[J]. Heat Treat. Met., 2016, 41(7): 79(刘磊, 杨甫, 吴勇. 硅改性铝化物涂层的CVD制备工艺[J]. 金属热处理, 2016, 41(7): 79)
[2] Dai J W, Yi J, Wang Z K, et al.High temperature oxidation behavior of Pt modified aluminide coating on single crystal superalloy[J]. J. Aeronaut. Mater., 2015, 35(5): 32(戴建伟, 易军, 王占考等. 单晶高温合金铂改性铝化物涂层的高温氧化行为[J]. 航空材料学报, 2015, 35(5): 32)
[3] Song P, Lu J S, Lv J G, et al.Influence factors of high temperature oxidation for Pt-modified-aluminide bond coatings[J]. Rare Met. Mater. Eng., 2010, 39: 304(宋鹏, 陆建生, 吕建国等. 铂铝涂层高温氧化的影响因素研究[J]. 稀有金属材料与工程, 2010, 39: 304)
[4] Xu Z H, Dai J W, Niu J, et al.Influence of deposition temperature on the phase structure and morphology of aluminide coatings[J]. Corros. Prot., 2013, 34: 991(许振华, 戴建伟, 牛静等. 沉积温度对铝化物涂层相结构与微观形貌的影响[J]. 腐蚀与防护, 2013, 34: 991)
[5] Mahesh R A, Jayaganthan R, Prakash S, et al.High temperature cyclic oxidation behavior of magnetron sputtered Ni-Al thin films on Ni- and Fe-based superalloys[J]. Mater. Chem. Phys., 2009, 114: 629
[6] Li H X, Qiao M, Zhou C G.Formation and cyclic oxidation resistance of Hf-Co-modified aluminide coatings on nickel base super-alloys[J]. Mater. Chem. Phys., 2014, 143: 915
[7] Liu Z J, Zhao X S, Guo H M, et al.Cyclic oxidation resistance of Ce/Co modified aluminide coatings on nickel base superalloys[J]. Corros. Sci., 2015, 94: 135
[8] Qiao M, Zhou C G.Hot corrosion behavior of Co modified NiAl coating on nickel base superalloys[J]. Corros. Sci., 2012, 63: 239
[9] Pei Y W, Zhou C G.Improved hot corrosion resistance of Dy-Co-modified aluminide coating by pack cementation process on nickel base superalloy[J]. Corros. Sci., 2016, 112: 710
[10] Liu Z J, Zhao X S, Zhou C G.Improved hot corrosion resistance of Y-Ce-Co-modified aluminide coating on nickel base superalloys by pack cementation process[J]. Corros. Sci., 2015, 92: 148
[11] Wu D L, Zhang H Y, Wei H, et al.Hot corrosion behavior of four modified aluminide coatings on DZ38G alloy[J]. J. Chin. Soc. Corros. Prot., 2014, 34: 502(吴多利, 张洪宇, 韦华等. 4种改性的铝化物涂层对DZ38G合金热腐蚀性能的影响[J]. 中国腐蚀与防护学报, 2014, 34: 502)
[12] Chen J H, Little J A.Degradation of the platinum aluminide coating on CMSX4 at 1100 ℃[J]. Surf. Coat. Technol., 1997, 92: 69
[13] Pint B A, Zhang Y.Performance of Al-rich oxidation resistant coatings for Fe-base alloys[J]. Mater. Corros., 2015, 62: 549
[14] Shen M L, Zhu S L.Advancement of technologies for preparing high-performance aluminide coatings[J]. Aeronaut. Manuf. Technol., 2016, 21: 105(沈明礼, 朱圣龙. 先进铝化物涂层制备技术进展[J]. 航空制造技术, 2016, 21: 105)
[15] Li W Y, Jiang R R, Huang C J, et al.Effect of cold sprayed Al coating on mechanical property and corrosion behavior of friction stir welded AA2024-T351 joint[J]. Mater. Des., 2015, 65: 757
[16] Mohammadi I, Afshar A.Modification of nanostructured anodized aluminum coatings by pulse current mode[J]. Surf. Coat. Technol., 2015, 278: 48
[17] Huang L, Sun X F, Guan H R, et al.Degradation behavior of aluminide coating on directionally solidified nickel base superalloy M951[J]. Corros. Sci. Prot. Technol., 2005, 17: 34(黄粮, 孙晓峰, 管恒荣等. 定向凝固高温合金M951低压渗铝涂层的高温氧化及相变过程[J]. 腐蚀科学与防护技术, 2005, 17: 34)
[18] Ren W P, Xiao C B, Li Q, et al.Microstructure evolution of cobalt aluminide coating on nickel-based superalloys during exposure at 1050 ℃[J]. Vacuum, 2014, 106: 39
[19] Ren W P, Li Q, Song J X, et al. Oxidation and microstructure evolution of cobalt aluminide coatings on directionally solidified superalloys during long term exposure at 1000 ℃[J]. Mater. Res. Innovat., 2014, 18(S4): S4-945-S4-951
[20] Rabiei A, Evans A G.Failure mechanisms associated with the thermally grown oxide in plasma sprayed thermal barrier coatings[J]. Acta Mater., 2000, 48: 3963
[21] Puetz P, Huang X A, Lima R S, et al.Characterization of transient oxide formation on CoNiCrAlY after heat treatment in vacuum and air[J]. Surf. Coat. Technol., 2010, 205: 647
[22] Felten E J, Pettit F S.Development, growth, and adhesion of Al2O3 on platinum-aluminum alloys[J]. Oxid. Met., 1976, 10: 189
[23] Wada K, Yamaguchi N, Matsubara H.Effect of substrate rotation on texture evolution in ZrO2-4 mol. % Y2O3 layers fabricated by EB-PVD[J]. Surf. Coat. Technol., 2005, 191: 367
[24] Bourban S, Karapatis N, Hofmann H, et al.Solidification microstructure of laser remelted Al2O3-ZrO2 eutectic[J]. Acta Mater., 1997, 45: 5069
[25] Angenete J, Stiller K.Oxidation of simple and Pt-modified aluminide diffusion coatings on Ni-base superalloys—II. Oxide scale failure[J]. Oxid. Met., 2003, 60: 83
[26] Liu G M, Li M S, Ma J H, et al.Transient oxidation behavior of nanocrystalline CoCrAlY coating at 1050 ℃[J]. Trans. Nonferrous Met. Soc. China, 2007, 17: 595
[27] Grabke H J, Bramm M W, Wagemann B.The oxidation of NiAl[J]. Mater. Corros., 1996, 47: 675
[28] Brumm M W, Grabke H J.The oxidation behaviour of NiAl—I. Phase transformations in the alumina scale during oxidation of NiAl and NiAl-Cr alloys[J]. Corros. Sci., 1992, 33: 1677
[29] Pint B A, Martin J R, Hobbs L W.The oxidation mechanism of θ-Al2O3 scales[J]. Solid State Ionics, 1995, 78: 99
[30] Balmain J, Loudjani M K, Huntz A M.Microstructural and diffusional aspects of the growth of Alumina scales on β-NiAl[J]. Mater. Sci. Eng., 1997, A224: 87
[31] Manap A, Nakano A, Ogawa K.The protectiveness of thermally grown oxides on cold sprayed CoNiCrAlY bond coat in thermal barrier coating[J]. J. Therm. Spray Technol., 2012, 21: 586
[32] Guo H B, Cui Y J, Peng H, et al.Improved cyclic oxidation resistance of electron beam physical vapor deposited nano-oxide dispersed beta-NiAl coatings for Hf-containing superalloy[J]. Corros. Sci., 2010, 52: 1440
[33] Zhang L C, Heuer A H.Microstructural evolution of the nickel platinum-aluminide bond coat on electron-beam physical-vapor deposition thermal-barrier coatings during high-temperature service[J]. Metall. Mater. Trans., 2005, 36A: 43
[34] Gale W F, King J E. Microstructural development in aluminide diffusion coatings on nickel-base superalloy single crystals [J]. Surf. Coat. Technol., 1992, 54-55: 8
[35] Basuki E, Crosky A, Gleeson B.Interdiffusion behaviour in aluminide-coated René 80H at 1150 ℃[J]. Mater. Sci. Eng., 1997, A224: 27
[36] Holmes J W, McClintock F A. The chemical and mechanical processes of thermal fatigue degradation of an aluminide coating[J]. Metall. Trans., 1990, 21A: 1209
[37] Zhang Y H, Knowles D M, Withers P J.Microstructural development in Pt-aluminide coating on CMSX-4 superalloy during TMF[J]. Surf. Coat. Technol., 1998, 107: 76
[38] González M A, Martínez D I, Saucedo C T, et al.Microstructural evolution of Pt-aluminide coating influencedby cycle oxidation service conditions[J]. Eng. Fail. Anal., 2013, 29: 122
[39] Ross E W, Sims C T. Superalloys II, Nickel-Base Alloys[M]. New York: Wiley, 1987: 98
[40] Guo J T.Materials Science and Engineering for Superalloys [M]. Beijing: Science Press, 2008: 92(郭建亭. 高温合金材料学 [M]. 上册. 北京: 科学出版社, 2008: 92)
[41] Kong Y H, Chen Q Z.Effect of minor additions on the formation of TCP phases in modified RR2086 SX superalloys[J]. Mater. Sci. Eng., 2004, A366: 135
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