Abstract
This paper presents a brief review of the current casting techniques for single-crystal (SC) blades, as well as an analysis of the solidification process in complex turbine blades. A series of novel casting methods based on the Bridgman process were presented to illustrate the development in the production of SC blades from superalloys. The grain continuator and the heat conductor techniques were developed to remove geometry-related grain defects. In these techniques, the heat barrier that hinders lateral SC growth from the blade airfoil into the extremities of the platform is minimized. The parallel heating and cooling system was developed to achieve symmetric thermal conditions for SC solidification in blade clusters, thus considerably decreasing the negative shadow effect and its related defects in the current Bridgman process. The dipping and heaving technique, in which thinshell molds are utilized, was developed to enable the establishment of a high temperature gradient for SC growth and the freckle-free solidification of superalloy castings. Moreover, by applying the targeted cooling and heating technique, a novel concept for the three-dimensional and precise control of SC growth, a proper thermal arrangement may be dynamically established for the microscopic control of SC growth in the critical areas of large industrial gas turbine blades.
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References
Versnyder F L, Shank M E. The development of columnar grain and single crystal high temperature materials through directional solidification. Materials Science and Engineering, 1970, 6(4): 213–247
Pratt D C. Industrial casting of superalloys. Materials Science and Technology, 1986, 2(5): 426–435
Quested P N, Osgerby S. Mechanical properties of conventionally cast, directionally solidified and single-crystal superalloys. Materials Science and Technology, 1986, 2(5): 461–475
Gebhardt A. Rapid Prototyping. Munich: Carl Hanser Verlag, 2006
Feriera J C, Santos E, Madureira H, et al. Integration of VP/RP/RT/ RE/RM for rapid product and process development. Rapid Prototyping Journal, 2006, 12(1): 18–28
Budzik G, Markowski T, Sobolak M. Hybrid foundry patterns of bevel gears. Archives of Foundry Engineering, 2007, 7(1): 131–134
Pattnaik S, Jha P K, Karunakar D B. A review of rapid prototyping integrated investment casting processes. Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials Design and Applications, 2014, 228(4): 249–277
Bridgman P W. US Patent, 1793672, 1931-02-24
Erickson J S, Owczarski W A, Curran P W. Process speeds up directional solidification. Metal Progress, 1971, 99: 58–60
Pratt D C. Industrial casting of superalloys. Materials Science and Technology, 1986, 2(5): 426–435
Elliott A J, Pollock T M, Tin S, et al. Directional solidification of large superalloy castings with radiation and liquid-metal cooling: A comparative assessment. Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science, 2004, 35(10): 3221–3231
Tschinkel J G, Giamei A F, Kearn B H. US Patent, 3763926, 1973-10-09
Giamei A F, Tschinkel J G. Liquid metal cooling: A new solidification technique. Metallurgical Transactions and Materials Transactions A: Physical Metallurgy and Materials Science, 1976, 7 (9): 1427–1434
Elliott A J. Directional solidification of large cross-section Ni-base superalloy castings via liquid-metal cooling. Dissertation for the Doctoral Degree. Ann Arbor: The University of Michigan, 2005
Liu L, Huang T, Qu M, et al. High thermal gradient directional solidification and its application in the processing of nickel-based superalloys. Journal of Materials Processing Technology, 2010, 210 (1): 159–165
Zhang J, Luo L. Directional solidification assisted by liquid metal cooling. Journal of Materials Science and Technology, 2007, 23: 289–300
Lohmüller A, Eβer W, Groβmann J, et al. Improved quality and economics of investment castings by liquid metal cooling—The selection of cooling media. In: Proceedings of International Symposium on Superalloys. 2000, 181–188
Konter M, Kats E, Hofmann N. A novel casting process for single crystal gas turbine components. In: Proceedings of International Symposium on Superalloys. 2000, 189–200
Wagner A, Shollock B A, McLean M. Grain structure development in directional solidification of nickel-base superalloys. Materials Science and Engineering A, 2004, 374(1-2): 270–279
Meyer ter Vehn M, Dedecke D, Paul U, et al. Undercooling related casting defects in SC turbine blades. In: Proceedings of International Symposium on Superalloys. 1996, 471–479
Zhou Y. Formation of stray grains during directional solidification of a nickel-based superalloy. Scripta Materialia, 2011, 65(4): 281–284
Tschinkel J G, Giamei A F, Kearn B H. US Patent, 3763926, 1973-10-09
Yang X L, Dong H B,Wang W, et al. Microscale simulation of stray grain formation in investment cast turbine blades. Materials Science and Engineering: A, 2004, 386(1-2): 129–139
Xuan W, Ren Z, Liu H, et al. Formation of stray grains in directionally solidified Ni-based superalloys with cross-section change regions. Materials Science Forum, 2013, 747–748: 535–539
Xuan W, Ren Z, Li C, et al. Formation of stray grain in cross section area for Ni-based superalloy during directional solidification. IOP Conference Series: Materials Science and Engineering, 2011, 27: 012035
Zhang J, Huang T, Liu L, et al. Advances in solidification characteristics and typical casting defects in nickel-based single crystal superalloys. Acta Metallurgica Sinica, 2015, 51(10): 1163–1178 (in Chinese)
Xuan W, Ren Z, Li C. Experimental evidence of the effect of a high magnetic field on the stray grains formation in cross-section change region for Ni-based superalloy during directional solidification. Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, 2015, 46(4): 1461–1466
Ma D, Wu Q, Bührig-Polaczek A. Undercoolability of superalloys and solidification defects in single crystal components. Advanced Materials Research, 2011, 278: 417–422
Ma D, Bührig-Polaczek A. Application of heat-conductor technique to production of SC turbine blade. Metallurgical and Materials Transactions. B, Process Metallurgy and Materials Processing Science, 2009, 40(5): 738–748
Ma D. Development of single crystal solidification technology for production of superalloy turbine blades. Acta Metallurgica Sinica, 2015, 51(10): 1179–1190 (in Chinese)
Ma D, Bührig-Polaczek A. Avoiding grain defects in single crystal components by application of a heat conductor technique. International Journal of Materials Research, 2009, 100(8): 1145–1151
Ma D, Bührig-Polaczek A. Development of heat conductor technique for single crystal components of superalloys. International Journal of Cast Metals Research, 2009, 22(6): 422–429
Yu J, Xu Q, Cui K, et al. Numerical simulation of solidification process on single crystal Ni-based superalloy investment castings. Journal of Materials Science and Technology, 2007, 23(1): 47–54
Napolitano R E, Schaefer R J. The convergence-fault mechanism for low-angle boundary formation in single-crystal castings. Journal of Materials Science, 2000, 35(7): 1641–1659
Ma D, Wu Q, Bührig-Polaczek A. Investigation on the asymmetry of thermal condition and grain defect formation in customary directional solidification process. IOP Conference Series: Materials Science and Engineering, 2011, 27: 012037
Ma D, Wu Q, Bührig-Polaczek A. Some new observations on freckle formation in directionally solidified superalloy components. Metallurgical and Materials Transactions. B, Process Metallurgy and Materials Processing Science, 2012, 43(2): 344–353
Ma D, Bührig-Polaczek A. The influence of surface roughness on freckle formation in directionally solidified superalloy samples. Metallurgical and Materials Transactions. B, Process Metallurgy and Materials Processing Science, 2012, 43(4): 671–677
Ma D, Bührig-Polaczek A. The geometry effect of freckle formation in the directionally solidified superalloy CMSX-4. Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, 2014, 45(3): 1435–1444
Ma D, Wang F, Wu Q, et al. Innovation of casting techniques for single crystal turbine blades of superalloys. In: Proceedings of International Symposium on Superalloys. 2016, 237–246
Ma D, Lu H, Bührig-Polaczek A. Experimental trials of the thin shell casting (TSC) technology for directional solidification. IOP Conference Series: Materials Science and Engineering, 2011, 27: 012036
Wang F, Ma D, Zhang J, et al. A high thermal gradient directional solidification method for growing superalloy single crystals. Journal of Materials Processing Technology, 2014, 214(12): 3112–3121
Wang F, Ma D, Bogner S, et al. Comparative investigation of the downward and upward directionally solidified single-crystal blades of superalloy CMSX-4. Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, 2016, 47(5): 2376–2386
Ma D, Grafe U. Dendrite growth and microsegregation during directional solidification: An analytical model and experimental studies on the superalloys CMSX-4. International Journal of Cast Metals Research, 2000, 13(2): 85–92
Ma D, Grafe U. Microsegregation in directionally solidified dendritic-cellular structure of superalloy CMSX-4. Materials Science and Engineering A, 1999, 270(2): 339–342
Feng Q, Carroll L J, Pollock T M. Solidification segregation in Ruthenium-containing nickel-base superalloys. Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, 2006, 37(6): 1949–1962
Caldwell E C, Fela F J, Fuchs G E. Segregation of elements in high refractory content single crystal nickel based superalloys. In: Proceedings of International Symposium on Superalloys. 2004. 811–818
Caldwell E C, Fela F J, Fuchs G E. The segregation of elements in high-refractory-content single-crystal nickel-based superalloys. Journal of Minerals, Metals and Materials, 2004, 56(9): 44–48
Heckl A, Rettig R, Singer R F. Solidification characteristics and segregation behavior of nickel-base superalloys in dependence on different rhenium and ruthenium contents. Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, 2010, 41(1): 202–211
Wang F, Ma D, Zhang J, et al. Investigation of segregation and density profiles in the mushy zone of CMSX-4 superalloy solidified during downward and upward directional solidification processes. Journal of Alloys and Compounds, 2015, 620: 24–30
Wang F, Ma D, Bogner S, et al. Comparative study of the segregation behavior and crystallographic orientation in a nickelbased single-crystal superalloy. Journal of Alloys and Compounds, 2015, 647: 528–532
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This work was funded by the Science and Technology Innovation Commission of Shenzhen Municipality (Grant No. JSGG20141016141652366) and the Economy, Trade and Information Commission of Shenzhen Municipality (Grant No. 2016-122).
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Ma, D. Novel casting processes for single-crystal turbine blades of superalloys. Front. Mech. Eng. 13, 3–16 (2018). https://doi.org/10.1007/s11465-018-0475-0
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DOI: https://doi.org/10.1007/s11465-018-0475-0