Microstructures and hardness of as-cast {C, Ta or Ti or Hf of Zr}-containing Cr-rich Niobium-based alloys candidate for uses at elevated temperatures

Patrice Berthod, Mélissa Léglise, Ghouti Medjahdi

Article ID: 842
Vol 2, Issue 2, 2019

VIEWS - 545 (Abstract) 411 (PDF)

Abstract


Four alloys based on niobium and containing about 33wt.%Cr, 0.4wt.C and, in atomic content equivalent to the carbon one, Ta, Ti, Hf or Zr, were elaborated by classical foundry under inert atmosphere. Their as-cast microstructures were characterized by X-ray diffraction, electron microscopy, energy dispersion spectrometry and while their room temperature hardness was specified by Vickers indentation. The microstructures are in the four cases composed of a dendritic Nb-based solid solution and of an interdendritic NbCr2 Laves phase. Despite the MC-former behavior of Ta, Ti, Hf and Zr usually observed in nickel or cobalt-based alloys, none of the four alloys contain MC carbides. Carbon is essentially visible as graphite flakes. These alloys are brittle at room temperature and hard to machine. Indentation shows that the Vickers hardness is very high, close to 1000HV10kg. Indentation lead to crack propagation through the niobium phase and the Laves areas. Obviously no niobium-based alloys microstructurally similar to high performance MC-strengthened nickel-based and cobalt-based can be expected. However the high temperature mechanical and chemical properties of these alloys remain to be investigated.

 


Keywords


Niobium-based Alloys; High Chromium Content; MC Carbide-former Elements; Microstructures; Hardne

Full Text:

PDF


References


1. Sims CT, Hagel WC(Eds.), The superalloys, John Wiley & Sons, Inc, New York, 1972.

2. Donachie MJ, Donachie SJ(Eds.), Superalloys: a technical guide (2nd edition), ASM International, Materials Park, 2002.

3. Nembach E, Neite G, Precipitation hardening of superalloys by ordered ’- particles, Progress in Materials Science 29 (1985) 177-319.

4. Klauke M, Mukherji D, Gorr B, et al, Oxidation behaviour of experimental Co-Re-base alloys in laboratory air at 1000 °C, International Journal of Materials Research (formerly Z. Metallkd.) 100(2009) 104-111.

5. Gorr B, Burk S, Depka T, et al, Effect of Si addition on the oxidation resistance of Co-Re-Cr-alloys: recent attainments in the development of novel alloys, International Journal of Materials Research (formerly Z. Metallkd.) 103 (2012) 24-30.

6. Cui C, Ping D, Gu Y, et al, A new Co-base superalloy strengthened by ’ phase, Materials Transactions 47 (2006) 2099-2102.

7. Mishra B, Ionescu M, Chandra T, Feasability of cast and wrought Co-Al-W-X gamma prime superalloys, Materials Science Forum 783-786 (2013) 1159-1164.

8. Gorr B, Azim M, Christ H-J, et al, Microstructure evolution in a new refractory high entropy alloy W-Mo-Cr-Ti-Al, Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science 47 (2016) 961-970.

9. Berthod P. High temperature properties of several chromium-containing Co-based alloys reinforced by different types of MC carbides (M = Ta, Nb, Hf and/or Zr), Journal of Alloys and Compounds, 481 (2009) 746-754.

10. Berthod P, Conrath E. As-cast microstructures and behavior at high temperature of chromium-rich cobalt-based alloys strengthened by hafnium carbides, Materials Chemistry and Physics, 143 (2014) 1139-1148.

11. Conrath E, Berthod P. Microstructure Evolution at High Temperature of Chromium-Rich Iron-based Alloys containing Hafnium Carbides, International Journal of Materials Research (formerly Z. Metallkd.), 105 (2014) 717-724.

12. Berthod P, Conrath E. Microstructure evolution in the bulk and surface states of chromium-rich nickel-based cast alloys reinforced by hafnium carbides after exposure to high temperature in air, Materials at High Temperature, 31 (2014) 266-273.

13. Berthod P, Conrath E. Creep and oxidation kinetics at 1100 °C of nickel-base alloys reinforced by hafnium carbides, Materials and Design, 104 (2016) 27-36.

14. Berthod P, Conrath E. Mechanical and Chemical Properties at High Temperature of {M-25Cr}-based Alloys Containing Hafnium Carbides (M=Co, Ni or Fe): Creep Behavior and Oxidation at 1200°C, Berthod P, Conrath E, Journal of Materials Science and Technology Research, 1 (2014) 7-14.

15. Berthod P. Looking for new polycrystalline MC-reinforced cobalt-based superalloys candidate to applications at 1200°C, Advances in Materials Science and Engineering, in press.

16. Berthod P. New polycrystalline MC-reinforced nickel-based superalloys for use at elevated temperatures (T > 1100°C), Advanced Materials Letters, submitted.

17. Shaffer PTB. High Temperature Materials. N°1 Materials Index, Plenum Press, New York, 1964.

18. Sims CT. Niobium in superalloys: a perspective, High Temperature Technology, 2 (1984) 185-201.

19. Dropmann MC, Stover D, Buchkremer HP, et al, Properties and processing of niobium superalloys by injection molding, Advances in Powder Metallurgy and Particulate Materials 8 (1992) 213-224.

20. Young D. High Temperature Oxidation and Corrosion of Metals, Elsevier, Amsterdam (2008).

21. Zhai Y, Lados DA, Brown EJ, et al, Fatigue crack growth behavior and microstructural mechanisms in Ti-6Al-4V manufactured by laser engineered net shaping, International Journal of Fatigue 93 (2016) 51-63.

22. Baldan A. Microstructural investigation of DS200 + hafnium superalloy, Zeitschrift für Metallkunde, 80 (1989) 635-642.

23. Kotval PS, Venables JD, Calder RW. Role of hafnium in modifying the microstructure of cast nickel-base superalloys, Metallurgical transactions, 3 (1972) 453-458.

24. Murata Y, Suga K, Yukawa N. Effect of transition elements on the properties of MC carbides in IN-100 nickel-based superalloy, Journal of Material Science 21 (1986) 3653-3660.

25. Opiekun Z. Influence of zirconium and heat treatment on the structure of heat-resistant cobalt casting alloys of MAR-M509 type, Journal of Material Science, 22 (1987) 1547-1556.

26. Tsai YL, Wang SF, Bor HY, et al, Effect of Zr addition of the microstructure and mechanical behavior of a fine-grained nickel-based superalloy at elevated temperature. Materials Science and Engineering A: Structural Materials: Properties, Microstructure and Processing, 607 (2014) 294-201.

27. Paul H, Darrieulat M, Vanderesse N, et al, Microstructyure of warm worked Zircalloy-4, Archives of Metallurgy and Materials, 55 (2010) 1007-1019.

28. https://www.webelements.com/niobium/physics.html

29. Zhu JH, Liu CT, Liaw PK. Phase stability and mechanical behavior of NbCr2-based Laves phases. Intermetallics, 7 (1999) 1011-1016.




DOI: https://doi.org/10.24294/tse.v2i2.842

Refbacks

  • There are currently no refbacks.


Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

Creative Commons License

This site is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.