Skip to main content

Advertisement

SpringerLink
Log in

Densification of thoria through flash sintering

  • Research Letter
  • Published:
MRS Communications Aims and scope Submit manuscript

Abstract

Thorium dioxide (thoria, ThO2) is used in refractory applications and as nuclear fuel. Its melting temperature, the highest of any binary oxide, makes it a difficult system to process. Here we report on the effects of flash sintering on the densification of thoria. We found 95% of theoretical density is obtained at ~950 °C (~30% of the melting temperature) with an electric field of 800 V/cm. Variation in power density had a minimal effect on the densification. Scanning electron microscopy images show the effects of flash sintering on grain size as a function of electric field.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6

Similar content being viewed by others

References

  1. C. Ronchi and J.P. Hiernaut: Experimental measurement of pre-melting and melting of thorium dioxide. J. Alloys Compd. 240, 179–;185 (1996).

    Article  CAS  Google Scholar 

  2. S. Peterson, R.E. Adams, and D.A. Douglas: Properties of thorium, its alloys, and its compounds. In Utilization of Thorium in Power Reactors, International Atomic Energy Agency (IAEA) Technical reports series No. 52 (IAEA, Vien.a. Austria, 1966), pp. 292–;312.

    Google Scholar 

  3. L.B. Amgaonkar, M.V. Rathod, A.P. Pardey, and S.P. Khandait: Thorium as a nuclear fuel. Int. J. Eng. Appl. Technol. AGNIPANKH-15, 48 (2015).

    Google Scholar 

  4. J.M. Pope and K.C. Radford: Physical properties of some thoria powders and their influence on sinterability. J. Nucl. Mater. 52, 241–;254 (1974).

    Article  CAS  Google Scholar 

  5. A. Baena, T. Cardinaels, J. Vleugels, K. Binnemans, and M. Verwerft: Activated sintering of ThO2 with Al2O3 under reducing and oxidizin conditions. J. Nucl. Mater. 470, 34–;43 (2016).

    Article  CAS  Google Scholar 

  6. K. Ananthasivan, S. Balakrishnan, S. Anthonysamy, R. Divakar, E. Mohandas, and V. Ganesan: Synthesis and sintering of nanocrystalline thoria doped with CaO and MgO derived through oxalate-deagglomeration. J. Nucl. Mater. 434, 223–;229 (2013).

    Article  CAS  Google Scholar 

  7. V. Chandramouli, S. Anthonysamy, P.R. Vasudeva Rao, R. Divakar, and D. Sundararaman: PVA aided microwave synthesis: a novel route for the production of nanocrystalline thoria powder. J. Nucl. Mater. 231, 213–;220 (1996).

    Article  CAS  Google Scholar 

  8. P. Balakrishna, B.P. Varma, T.S. Krishnan, T.R.R. Mohan, and P. Ramakrishnan: Thorium-oxide—calcination, compaction and sintering. J. Nucl. Mater. 160, 88–;94 (1988).

    Article  CAS  Google Scholar 

  9. P. Balakrishna, B.P. Varma, T.S. Krishnan, T.R.R. Mohan, and P. Ramakrishnan: Low-temperature sintering of thoria. J. Mater. Sci. Lett. 7, 657–;660 (1988).

    Article  CAS  Google Scholar 

  10. K. Ananthasivan, S. Anthonysamy, C. Sudha, A.L.E. Terrance, and P.R.V. Rao: Thoria doped with cations of group VB-synthesis and sintering. J. Nucl. Mater. 300, 217–;229 (2002).

    Article  CAS  Google Scholar 

  11. H. Muta, Y. Murakami, M. Uno, K. Kurosaki, and S. Yamanaka: Thermophysical properties of Th1-xUxO2 pellets prepared by spark plasma sintering technique. J. Nucl. Sci. Technol. 50, 181–;187 (2013).

    Article  CAS  Google Scholar 

  12. V. Tyrpekl, M. Cologna, D. Robba, and J. Somers: Sintering behaviour of nanocrystalline ThO2 powder using spark plasma sintering. J. Eur. Ceram. Soc. 36, 767–;772 (2016).

    Article  CAS  Google Scholar 

  13. A.M. Raftery, J.G. Pereira da Silva, D.D. Byler, D.A. Andersson, B.P. Uberuaga, C.R. Stanek, and K.J. McClellan: Onset conditions for flash sintering of UO2. J. Nucl. Mater. 493, 264–;270 (2017).

    Article  CAS  Google Scholar 

  14. M. Cologna, B. Rashkova, and R. Raj: Flash sintering of nanograin zirconia in < 5 s at 850 °C. J. Am. Ceram. Soc. 93, 3556–;3559 (2010).

    Article  CAS  Google Scholar 

  15. J.S.C. Francis, M. Cologna, and R. Raj: Particle size effects in flash sintering. J. Eur. Ceram. Soc. 32, 3129–;3136 (2012).

    Article  CAS  Google Scholar 

  16. M. Cologna, J.S.C. Francis, and R. Raj: Field assisted and flash sintering of alumina and its relationship to conductivity and MgO-doping. J. Eur. Ceram. Soc. 31, 2827–;2837 (2011).

    Article  CAS  Google Scholar 

  17. S. Kim, S.L. Kang, and I. Chen: Electro-sintering of yttria-stabilized cubic zirconia. J. Am. Ceram. Soc. 96, 1398–;1406 (2013).

    Article  CAS  Google Scholar 

  18. W. Rheinheimer, M. Fülling, and M.J. Hoffmann: Grain growth in weak electric fields in strontium titanate: grain growth acceleration by defect redistribution. J. Eur. Ceram. Soc. 36, 2773–;2780 (2016).

    Article  CAS  Google Scholar 

  19. W. Qin, H. Majidi, J. Yun, and K. van Benthem: Electrode effects on microstructure formation during FLASH sintering of yttrium-stabilized zirconia. J. Am. Ceram. Soc. 99, 2253–;2259 (2016).

    Article  CAS  Google Scholar 

  20. J.G. Pereira da Silva, H.A. Al-Qureshi, F. Keil, and R. Janssen: A dynamic bifurcation criterion for thermal runaway during the flash sintering of ceramics. J. Eur. Ceram. Soc. 36, 1261–;1267 (2016).

    Article  Google Scholar 

  21. R.I. Todd, E. Zapata-Solvas, R.S. Bonilla, T. Sneddon, and P.R. Wilshaw: Electrical characteristics of flash sintering: thermal runaway of Joule heating. J. Eur. Ceram. Soc. 35, 1865–;1877 (2015).

    Article  CAS  Google Scholar 

  22. Y. Dong and I. Chen: Predicting the onset of flash sintering. J. Am. Ceram. Soc. 98, 2333–;2335 (2015).

    Article  CAS  Google Scholar 

  23. Y. Dong and I.W. Chen: Onset criterion for flash sintering. J. Am. Ceram. Soc. 98, 3624–;3627 (2015).

    Article  CAS  Google Scholar 

  24. S.K. Jha, J.M. Lebrun, and R. Raj: Phase transformation in the alumina-;titania system during flash sintering experiments. J. Eur. Ceram. Soc. 36, 733–;739 (2016).

    Article  CAS  Google Scholar 

  25. J.A. Downs and V.M. Sglavo: Electric field assisted sintering of cubic zirconia at 390 degrees C. J. Am. Ceram. Soc. 96, 1342–;1344 (2013).

    Article  CAS  Google Scholar 

  26. A.L.G. Prette, M. Cologna, V. Sglavo, and R. Raj: Flash-sintering of Co2MnO4 spinel for solid oxide fuel cell applications. J. Power Sources 196, 2061–;2065 (2011).

    Article  CAS  Google Scholar 

  27. R.W.G. Wyckoff: Crystal Structures (John Wiley, New York, 1963).

    Google Scholar 

  28. H.S. Maiti and E.C. Subbarao: Electrical-conduction in CaO-doped thoria electrolytes. J. Electrochem. Soc. 123, 1713–;1718 (1976).

    Article  CAS  Google Scholar 

  29. W.E. Danforth and F.H. Morgan: Electrical resistance of thoria. Phys. Rev. 79, 142–;144 (1950).

    Article  CAS  Google Scholar 

  30. M. Iqbal and E.H. Baker: Conductivity measurements on thoria and thoria—yttria solid solutions at high oxygen pressures. High Temp. Press. 5, 265–;271 (1973).

    CAS  Google Scholar 

  31. A. Hammou and C. Deportes: Electrical conductivity and defect structure in thorium-dioxide at high-temperature: study of ionic and electronic conductivities. J. Chime Phys. Phys.-Chim. Biol. 71, 1071–;1080 (1974).

    Article  CAS  Google Scholar 

  32. M. Aizenshtein, T.Y. Shvareva, and A. Navrotsky: Thermochemistry of lanthana- and yttria-dope thorial. J. Am. Ceram. Soc. 93, 4142–;4147 (2010).

    Article  CAS  Google Scholar 

  33. P.L. Chen and I.W. Chen: Role of defect interaction in boundary mobility and cation diffusivity of CeO2. J. Am. Ceram. Soc. 77, 2289–;2297 (1994).

    Article  CAS  Google Scholar 

  34. P.L. Chen and I.W. Chen: Grain boundary mobility in Y2O3: defect mechanism and dopant effects. J. Am. Ceram. Soc. 79, 1801–;1809 (1996).

    Article  CAS  Google Scholar 

  35. P.L. Chen and I.W. Chen: Grain growth in CeO2: dopant effects, defect mechanism, and solute drag. J. Am. Ceram. Soc. 79, 1793–;1800 (1996).

    Article  CAS  Google Scholar 

  36. Y. Dong, H. Wang, and I.W. Chen: Electrical and hydrogen reduction enhances kinetics in doped zirconia and ceria I. Grain growth study. J. Am. Ceram. Soc. 100, 876–;886 (2017).

    Article  CAS  Google Scholar 

  37. M. Biesuz and V.M. Sglavo: Flash sintering of alumina: effect of different operating conditions on densification. J. Eur. Ceram. Soc. 36, 2535–;2542 (2016).

    Article  CAS  Google Scholar 

Download references

Acknowledgments

The authors thank Roger Russell and Toby Tung for their help with the experimental setup, the Clemson University Electron Microscopy Laboratory for allowing us to utilize their SEMs, and Brian Powell for his assistance in acquiring the electron images. In addition, we acknowledge NSF support for the REU on Advanced Materials for Environmental Sustainability under grant EEC 1156762 which funded one ofthe authors (S. A.).

Author information

Authors and Affiliations

  1. Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27606, USA

    W. Straka, S. Amoah & J. Schwartz

  2. Department of Physics, Lenoir Rhyne University, Hickory, NC, 28601, USA

    S. Amoah

Authors
  1. W. Straka
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. S. Amoah
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. J. Schwartz
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to W. Straka.

Supplementary Materials

Supplementary Materials

The supplementary material for this article can be found at https://doi.org/10.1557/mrc.2017.70.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Straka, W., Amoah, S. & Schwartz, J. Densification of thoria through flash sintering. MRS Communications 7, 677–682 (2017). https://doi.org/10.1557/mrc.2017.70

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1557/mrc.2017.70

Search

Navigation