Investment casting and high temperature alloys

The chair uses two investment casting plants of different sizes (casting weights max. 10 kg or max 0,6 kg), in which innovative cooling technologies can be realized.Based on experience with the LMC (Liquid Metal Cooling) process, our research is focused on the investigation of the newly developed FCBC (Fluidized Carbon Bed Cooling) process for the single crystalline solidification of superalloys. In comparison with commercially available investment casting processes it could be shown that FCBC benefits from a higher cooling potential. In combination with a dynamic baffle a higher axial temperature gradient will evolve. Objective is the improvement of the process understanding as well as the process optimization, carried out on a 10 kg prototype plant. A further point of interest is the exploitation of the increased microstructural homogeneity for alloy development. The material development is carried out in close cooperation with the group High Performance Alloys of the chair.
These activitis are embedded in the collaborative research centre DFG TR 103 “From Atom to Turbine Blade” (http://www.sfb-transregio103.de/).

• Schulze H., Zenk C., Körner C.:
  Improving Microstructural Homogeneity of Investment-Cast Single-Crystalline Ni-Base Superalloys by Using Fluidized Carbon Bed Cooling
  In: Advanced Engineering Materials (2024)
  ISSN: 1438-1656
  DOI: 10.1002/adem.202302123
• Git P., Hofmeister M., Singer R., Körner C.:
  Fluidization behavior of graphitized glassy particles in a fluidized carbon bed cooling process for investment casting
  In: Particuology 65 (2022), p. 32-38
  ISSN: 1674-2001
  DOI: 10.1016/j.partic.2021.07.001
• Wahlmann B., Bandorf J., Volz N., Förner A., Pröbstle J., Multerer K., Göken M., Markl M., Neumeier S., Körner C.:
  Numerical Design of CoNi-Base Superalloys With Improved Casting Structure
  In: Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science (2022)
  ISSN: 1073-5623
  DOI: 10.1007/s11661-022-06870-4
• Gaag T., Ritter N., Peters A., Volz N., Gruber D., Neumeier S., Zenk C., Körner C.:
  Improving the Effectiveness of the Solid-Solution-Strengthening Elements Mo, Re, Ru and W in Single-Crystalline Nickel-Based Superalloys
  In: Metals 11 (2021), Article No.: 1707
  ISSN: 2075-4701
  DOI: 10.3390/met11111707
• Ritter N.:
  Bedeutung der Mischkristallhärter für die Kriechbeständigkeit Re-freier Nickelbasis-Einkristall-Legierungen (Dissertation, 2021)
• Horst OM., Adler D., Git P., Wang H., Streitberger J., Holtkamp M., Jöns N., Singer R., Körner C., Eggeler G.:
  Exploring the fundamentals of Ni-based superalloy single crystal (SX) alloy design: Chemical composition vs. microstructure
  In: Materials & Design 195 (2020), Article No.: 108976
  ISSN: 0264-1275
  DOI: 10.1016/j.matdes.2020.108976
• Zenk C., Volz N., Zenk C., Felfer P., Neumeier S.:
  Impact of the Co/Ni-Ratio on Microstructure, Thermophysical Properties and Creep Performance of Multi-Component γ′-Strengthened Superalloys
  In: Crystals 10 (2020), p. 1058
  ISSN: 2073-4352
  DOI: 10.3390/cryst10111058
• Horst OM., Ibrahimkhel S., Streitberger J., Wochmjakow N., Git P., Scholz F., Thome P., Singer R., Körner C., Frenzel J.,  Eggeler G.:
  On the Influence of Alloy Composition on Creep Behavior of Ni-Based Single-Crystal Superalloys (SXs)
  14th International Symposium on Superalloys, Superalloys 2021 (Seven Springs, PA, 12. September 2021 - 16. September 2021)
  In: Sammy Tin, Mark Hardy, Justin Clews, Jonathan Cormier, Qiang Feng, John Marcin, Chris O'Brien, Akane Suzuki (ed.): Minerals, Metals and Materials Series 2020
  DOI: 10.1007/978-3-030-51834-9_6
• Zenk C., Volz N., Bezold A., Huber LK., Eggeler Y., Spiecker E., Göken M., Neumeier S.:
  The Effect of Alloying on the Thermophysical and Mechanical Properties of Co–Ti–Cr-Based Superalloys
  DOI: 10.1007/978-3-030-51834-9_89
• Volz N., Zenk C., Halvaci T., Matuszewska K., Neumeier S., Göken M.:
  Castability and Recrystallization Behavior of γ′-Strengthened Co-Base Superalloys
  DOI: 10.1007/978-3-030-51834-9_88
• Hofmeister M.:
  Entwicklung eines wirbelbettbasierten Feingussverfahrens zur Verbesserung der Erstarrungsmikrostruktur von gerichtet erstarrten Superlegierungsbauteilen (Dissertation, 2020)
• Ritter N., Sowa R., Schauer JC., Gruber D., Göhler T., Rettig R., Körner C., Singer R.:
  Effects of Solid Solution Strengthening Elements Mo, Re, Ru, and W on Transition Temperatures in Nickel-Based Superalloys with High γ′-Volume Fraction: Comparison of Experiment and CALPHAD Calculations
  In: Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science (2018)
  ISSN: 1073-5623
  DOI: 10.1007/s11661-018-4730-0
• Hofmeister M., Franke M., Körner C., Singer R.:
  Single Crystal Casting with Fluidized Carbon Bed Cooling: A Process Innovation for Quality Improvement and Cost Reduction
  In: Metallurgical and Materials Transactions B-Process Metallurgy and Materials Processing Science 48 (2017), p. 3132-3142
  ISSN: 1073-5615
  DOI: 10.1007/s11663-017-1110-x
• Ritter N., Schesler E., Müller A., Rettig R., Körner C., Singer R.:
  On the Influence of Ta and Ti on Heat-Treatability and γ/γ'-Partitioning of High W Containing Re-Free Nickel-Based Superalloys
  In: Advanced Engineering Materials (2017)
  ISSN: 1438-1656
  DOI: 10.1002/adem.201700150
• Pröbstle M., Neumeier S., Feldner P., Rettig R., Helmer H., Singer R., Göken M.:
  Improved creep strength of nickel-base superalloys by optimized γ/γ′ partitioning behavior of solid solution strengthening elements
  In: Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing 676 (2016), p. 411-420
  ISSN: 0921-5093
  DOI: 10.1016/j.msea.2016.08.121
• Goehler T., Schwalbe C., Svoboda J., Affeldt E., Singer R.:
  Discussing the effect of gamma prime coarsening on high temperature low stress creep deformation with respect to the role of refractory elements
  13th International Symposium on Superalloys, SUPERALLOYS 2016 (Seven Springs, 11. September 2016 - 15. September 2016)
  In: M. Hardy, E. Huron, U. Glatzel, B. Griffin, B. Lewis, C. Rae, V. Seetharaman, S. Tin (ed.): Superalloys 2016: Proceedings of the 13th Intenational Symposium of Superalloys 2016
  DOI: 10.1002/9781119075646.ch70
• Rettig R., Matuszewski K., Müller A., Helmer H., Ritter N., Singer R.:
  Development of a low-density rhenium-free single crystal nickel-based superalloy by application of numerical multi-criteria optimization using thermodynamic calculations
  13th International Symposium on Superalloys, SUPERALLOYS 2016 (Seven Springs, 11. September 2016 - 15. September 2016)
  In: M. Hardy, E. Huron, U. Glatzel, B. Griffin, B. Lewis, C. Rae, V. Seetharaman, S. Tin (ed.): Superalloys 2016: Proceedings of the 13th Intenational Symposium of Superalloys 2016
  DOI: 10.1002/9781119075646.ch4
• Matuszewski K.:
  Precepetation of Topologically Close Packed Phases in Ni-base Superalloys - the Effect of Re and Ru (Dissertation, 2016)
• Göhler T.:
  Designkriterien für rheniumreduzierte Nickelbasis-Einkristalllegierungen: Identifikation und rechnergestützte Umsetzung (Dissertation, 2016)
• Matuszewski K., Rettig R., Matysiak H., Peng Z., Povstugar I., Choi P., Müller J., Raabe D., Spiecker E., Kurzydlowski KJ., Singer R.:
  Effect of ruthenium on the precipitation of topologically close packed phases in Ni-based superalloys of 3rd and 4th generation
  In: Acta Materialia 95 (2015), p. 274-283
  ISSN: 1359-6454
  DOI: 10.1016/j.actamat.2015.05.033
• Hofmeister M., Klein L., Miran H., Rettig R., Virtanen S., Singer R.:
  Corrosion behaviour of stainless steels and a single crystal superalloy in a ternary LiCl-KCl-CsCl molten salt
  In: Corrosion Science 90 (2015), p. 46-53
  ISSN: 0010-938X
  DOI: 10.1016/j.corsci.2014.09.009
• Matuszewski K., Müller A., Ritter N., Rettig R., Kurzydłowski K., Singer R.:
  On the Thermodynamics and Kinetics of TCP Phase Precipitation in Re- and Ru- Containing Ni-base Superalloys
  In: Advanced Engineering Materials 17 (2015), p. 1127-1133
  ISSN: 1438-1656
  DOI: 10.1002/adem.201500173
• Rettig R., Ritter N., Müller F., Franke M., Singer R.:
  Optimization of the Homogenization Heat Treatment of Nickel-Based Superalloys Based on Phase-Field Simulations: Numerical Methods and Experimental Validation
  In: Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science 46 (2015), p. 5842-5855
  ISSN: 1073-5623
  DOI: 10.1007/s11661-015-3130-y
• Matuszewski K., Rettig R., Rasiński M., Kurzydlowski KJ., Singer R.:
  The Three-dimensional morphology of topologically close packed phases in a high rhenium containing nickel based superalloy
  In: Advanced Engineering Materials 16 (2014), p. 171-175
  ISSN: 1438-1656
  DOI: 10.1002/adem.201300198
• Rettig R., Singer R.:
  Fast interpolation algorithm for the calculation of thermodynamic property maps of microstructures
  In: Modelling and Simulation in Materials Science and Engineering 22 (2014), p. 1-19
  ISSN: 1361-651X
  DOI: 10.1088/0965-0393/22/8/085002
• Matuszewski K., Rettig R., Singer R.:
  The effect of Ru on precipitation of topologically close packed phases in Re-containing Ni base superalloys: Quantitative FIB-SEM investigation and 3D image modeling
  2nd European Symposium on Superalloys and Their Applications, EUROSUPERALLOYS 2014 (Giens)
  DOI: 10.1051/matecconf/20141409001
• Franke M., Hilbinger RM., Lohmüller A., Singer R.:
  The effect of liquid metal cooling on thermal gradients in directional solidification of superalloys: Thermal analysis
  In: Journal of Materials Processing Technology 213 (2013), p. 2081-2088
  ISSN: 0924-0136
  DOI: 10.1016/j.jmatprotec.2013.06.001
• Franke M.:
  Auswirkungen der Legierungszusammensetzung auf die Morphologie und die Festigkeit des Dendritennetzwerkes bei der gerichteten Erstarrung von Nickelbasis-Superlegierungen (Dissertation, 2013)
• Heckl A., Cenanovic S., Göken M., Singer R.:
  Discontinuous precipitation and phase stability in Re- and Ru-containing nickel-base superalloys
  In: Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science 43 (2012), p. 10-19
  ISSN: 1073-5623
  DOI: 10.1007/s11661-011-0833-6
• Rettig R., Singer R.:
  Influence of Ruthenium on topologically closed packed phase precipitation in single-crystal Ni-based superalloys: numerical experiments and validation
  112th International Symposium on Superalloys, SUPERALLOYS 2012 (Seven Springs, 9. September 2012 - 13. September 2012)
  In: E. S. Huron, R. C. Reed, M. C. Hardy, M. J. Mills, R. E. Montero, P. Dolabella Portella, J. Telesman (ed.): Superalloys 2012: Proceedings of the 12th Intenational Symposium of Superalloys 2012
• Rettig R., Singer R.:
  Numerical modelling of precipitation of topologically close-packed phases in nickel-base superalloys
  In: Acta Materialia 59 (2011), p. 317-327
  ISSN: 1359-6454
  DOI: 10.1016/j.actamat.2010.09.035
• Heckl A., Neumeier S., Cenanovic S., Göken M., Singer R.:
  Reasons for the enhanced phase stability of Ru-containing nickel-based superalloys
  In: Acta Materialia 59 (2011), p. 6563-6573
  ISSN: 1359-6454
  DOI: 10.1016/j.actamat.2011.07.002
• Franke M., Hilbinger RM., Konrad C., Glatzel U., Singer R.:
  Numerical determination of secondary dendrite arm spacing for IN738LC investment castings
  In: Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science 42 (2011), p. 1847-1853
  ISSN: 1073-5623
  DOI: 10.1007/s11661-010-0585-8
• Rettig R., Heckl A., Singer R.:
  Modeling of precipitation kinetics of TCP-phases in single crystal nickel-base superalloys
  In: Advanced Materials Research 278 (2011), p. 180-185
  ISSN: 1022-6680
  DOI: 10.4028/www.scientific.net/AMR.278.180
• Franke M., Hilbinger RM., Heckl A., Singer R.:
  Effect of thermophysical properties and processing conditions on primary dendrite arm spacing of nickel-base superalloys - Numerical approach
  In: Gießereiforschung 278 (2011), p. 156-161
  ISSN: 0046-5933
  DOI: 10.4028/www.scientific.net/AMR.278.156
• Rettig R., Ritter N., Helmer H., Neumeier S., Singer R.:
  Single-crystal nickel-based superalloys developed by numerical multi-criteria optimization techniques: Design based on thermodynamic calculations and experimental validation
  In: Modelling and Simulation in Materials Science and Engineering 23 (2015), Article No.: 035004
  ISSN: 1361-651X
  DOI: 10.1088/0965-0393/23/3/035004
• Peng Z., Povstugar I., Matuszewski K., Rettig R., Singer R., Kostka A., Choi PP., Raabe D.:
  Effects of Ru on elemental partitioning and precipitation of topologically close-packed phases in Ni-based superalloys
  In: Scripta Materialia 101 (2015), p. 44-47
  ISSN: 1359-6462
  DOI: 10.1016/j.scriptamat.2015.01.014
• Heckl A., Rettig R., Singer R.:
  Creep rupture strength of Re and Ru containing experimental nickel-base superalloys
  In: Advanced Materials Research 278 (2011), p. 339-344
  ISSN: 1022-6680
  DOI: 10.4028/www.scientific.net/AMR.278.339
• Heckl A., Neumeier S., Göken M., Singer R.:
  The effect of Re and Ru on γ/γ′ microstructure, γ-solid solution strengthening and creep strength in nickel-base superalloys
  In: Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing 528 (2011), p. 3435-3444
  ISSN: 0921-5093
  DOI: 10.1016/j.msea.2011.01.023
• Heckl A.:
  Auswirkungen von Rhenium und Ruthenium auf die Mikrostruktur und Hochtemperaturfestigkeit von Nickel-Basis Superlegierungen unter Berücksichtigung der Phasenstabilität (Dissertation, 2011)
• Heckl A., Rettig R., Singer R.:
  Solidification Characteristics and Segregation Behavior of Nickel-Base Superalloys in Dependence on Different Rhenium and Ruthenium Contents
  In: Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science 41A (2010), p. 202-211
  ISSN: 1073-5623
  DOI: 10.1007/s11661-009-0076-y
• Heckl A., Rettig R., Cenanovic S., Göken M., Singer R.:
  Investigation of the final stages of solidification and eutectic phase formation in Re and Ru containing nickel-base superalloys
  In: Journal of Crystal Growth 312 (2010), p. 2137-2144
  ISSN: 0022-0248
  DOI: 10.1016/j.jcrysgro.2010.03.041
• Rettig R.:
  Mathematische Modellierung der Ausscheidung von Sprödphasen in komplexen rutheniumhaltigen Nickelbasis-Superlegierungen (Dissertation, 2010)
• Rettig R., Heckl A., Neumeier S., Pyczak F., Göken M., Singer R.:
  Verification of a commercial CALPHAD database for Re and Ru containing nickel-base superalloys
  In: Defect and Diffusion Forum 289-292 (2009), p. 101-108
  ISSN: 1012-0386
  DOI: 10.4028/www.scientific.net/DDF.289-292.101
• Singer R., Lamm M.:
  The effect of casting conditions on the high-cycle fatigue properties of the single-crystal nickel-base superalloy PWA 1483
  In: Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science 38A (2007), p. 1177-1183
  ISSN: 1073-5623
  DOI: 10.1007/s11661-007-9188-4
• Lamm M.:
  Einfluss der Erstarrungsbedingungen auf die mechanischen Eigenschaften von einkristallinen Superlegierungewn bei großen Wandstärken (Dissertation, 2007)
• Volek A., Singer R., Bürgel R., Grossmann J., Wang Y.:
  Influence of topologically closed packed phase formation on creep rupture life of directionally solidified nickel-base superalloys
  In: Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science 37 (2006), p. 405-410
  ISSN: 1073-5623
  DOI: 10.1007/s11661-006-0011-4
• Hördler M.:
  Phasengrenzreaktion im Fest-Flüssig-System Nickel/Zinn (Dissertation, 2006)
• Volek A., Pyczak F., Singer R., Mughrabi H.:
  Partitioning of Re between γ and γ′ phase in nickel-base superalloys
  In: Scripta Materialia 52 (2005), p. 141-145
  ISSN: 1359-6462
  DOI: 10.1016/j.scriptamat.2004.09.013
• Bürgel R., Grossmann J., Lüsebrink O., Mughrabi H., Pyczak F., Singer R., Volek A.:
  Development of a new alloy for directional solidification of large industrial gas turbine blades
  SUPERALLOYS 2004 - Tenth International Symposium on Superalloys (Champion, PA)
• Volek A., Singer R.:
  Influence of solidification conditions on TCP phase formation, casting porosity and high temperature mechanical properties in a Re-containing nickel-base superalloy with columnar grain structure
  10th International Symposium on Superalloys, SUPERALLOYS 2004 (Seven Springs, 19. September 2004 - 23. September 2004)
  In: K. Green, H. Harada, T.E. Howson, T.M. Pollock, R.C. Reed, J.J. Schirra, S. Walston (ed.): Superalloys 2004: Proceedings of the 10th Intenational Symposium of Superalloys 2004
  DOI: 10.7449/2004/Superalloys_2004_713_718
• Lohmüller A.:
  Gerichtete Erstarrung mittels Flüssigmetallkühlung - Verfahrensoptimierung und Parametereinflüsse (Dissertation, 2002)
• Volek A.:
  Erstarrungsmikrostruktur und Hochtemperatureigenschaften rheniumhaltiger, stängelkristalliner Nickel-Basis-Superlegierungen (Dissertation, 2002)
• Pfennig A.:
  Mikrostruktur und Eigenschaften keramischer Formmassen im Feinguss (Dissertation, 2001)
• Pyczak F., Biermann H., Mughrabi H., Volek A., Singer R.:
  CBED-Measurement of Residual Internal Strains in the Neighbourhood of TCP-Phases in Ni-Base Superalloys
  9th International Symposium on Superalloys, SUPERALLOYS 2000 (Seven Springs, 17. September 2000 - 21. September 2000)
  In: K. Green, T. M. Pollock, R. Kissinger, R.R. Bowman, K.A. Green, M. McLean, S. Olson, J.J. Schirra (ed.): Superalloys 2000: Proceedings of the 9th Intenational Symposium of Superalloys 2000
• Lohmüller A., Eßer W., Großmann J., Hördler M., Preuhs J., Singer R.:
  Improved Quality and Economics of Investment Castings by Liquid Metal Cooling Media - The Selection of Cooling Media
  9th International Symposium on Superalloys, SUPERALLOYS 2000 (Seven Springs, 17. September 2000 - 21. September 2000)
  In: K. Green, T. M. Pollock, R. Kissinger, R.R. Bowman, K.A. Green, M. McLean, S. Olson, J.J. Schirra (ed.): Superalloys 2000: Proceedings of the 9th Intenational Symposium of Superalloys, Warrendale: 2000
  DOI: 10.7449/2000/Superalloys_2000_181_188
• Grossmann J., Preuhs J., Eßer W., Singer R.:
  Investment Casting of High Performance Turbine Blades by Liquid Metal Cooling - A Step Forward Towards Industrial Scale Manufacturing
  International Symposium on Liquid Metal Processing and Castings (Santa Fe)
• Krug P.:
  Einfluss einer Flüssigkeitskühlung auf die Mikrostruktur gerichtet erstarrter Superlegierungen (Dissertation, 1998)
• Fitzgerald T., Singer R.:
  An analytical model for optimal directional solidification using liquid metal cooling
  In: Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science 28 (1997), p. 1377-1383
  ISSN: 1073-5623
  URL: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0031164995&origin=inward
• Singer R.:
  Möglichkeiten der Effizienzsteigerung von Gasturbinen durch innovative Werkstofftechnik
  In: VDI-Berichte (1995), p. 389-396
  ISSN: 0083-5560
• Fitzgerald T., Singer R.:
  Modeling of the Directional Solidification of Turbine Blades via Liquid Metal Cooling
  2nd Pacific Rim Int. Conf. on Modeling of Casting and Solidification (Hitachi, 25. January 1995 - 27. January 1995)
  In: E. Niyama, H. Kodama (ed.): Conf. Proc., 2nd Pacific Rim Int. Conf. on Modeling of Casting and Solidification 1995
• Hugo F., Mayer H., Singer R.:
  Directional and Single Crystal Solidification using Liquid Metal Cooling
  42nd Annual Technical Meeting and Tabletop Exhibition, Investment Casting Institute (Atlanta)
  In: Conference Proceedings, 42nd Annual Technical Meeting and Tabletop Exhibition, Investment Casting Institute, Atlanta, Georgia 1994
• Singer R.:
  Advanced Materials and Processes for Land-Based Gas Turbines
  Materials for Advanced Power Engineering (Liege, 3. October 1994 - 6. October 1994)
  In: D. Coutsouradis et al. (ed.): Materials for Advanced Power Engineering 1994