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Spray freeze drying of YSZ nanopowder

  • Bala P. C. Raghupathy
  • J. G. P. Binner
Research Paper

Abstract

Spray freeze drying of yttria stabilised zirconia nanopowders with a primary particle size of ~16 nm has been undertaken using different solids content starting suspensions, with the effect of the latter on the flowability and crushability of the granules being investigated. The flowability and fill density of the granules increased with an increase in the solid content of the starting suspension, whilst the crushability decreased. The powder flowability, measured using a Hall flowmeter and model shoe-die filling tests, showed that the flowability of otherwise poorly flowable nanopowders can be improved to match that of the commercial spray dried submicron powder. The 5.5 vol.% solid content based suspension yielded soft agglomerates whilst a 28 vol.% solid content suspension formed hard agglomerates on spray freeze drying; the granule relics were visible in the fracture surface of the die pressed green compact in the latter case. The increase in granule strength is explained by the reduction in inter-particle distance based on the theories developed by Rumpf and Kendall. The flaw sizes computed using the Kendall model are comparable with those seen in the micrographs of the granule. With an optimum solid content, it is possible to have a granulated nanopowder with reasonable flowability and compactability resulting in homogeneous green bodies with ~54 % of theoretical density.

Keywords

YSZ Spray freeze drying Agglomerate strength Powder flowability Die pressing Nitrogen adsorption isotherms Nanostructured ceramics 

Notes

Acknowledgments

The authors would like to thank EPSRC/PowdermatriX for financial support, Prof. Alan Cocks, Oxford University, UK, and Dr. Farhad Motazedian, Leicester University, UK, for the model shoe-die filing experiments and Mr. Nikolaos Vlachos and Prof. Issac Chang, Birmingham University, UK, for use of their Hall flowmeter. Single granule strength tests were done by Ms. Susannah Eckhard and Ms. Jing (Sherry) Liu at the Fraunhofer Institut Keramische Technologien und Systeme in Dresden, Germany, and their time and access to the equipment is gratefully acknowledged.

Supplementary material

Supplementary material 1 (WMV 3951 kb)

References

  1. Adi S, Adi H, Chan H, Finlay WH, Tong Z, Yang RYuA (2011) Agglomerate strength and dispersion of pharmaceutical powders. J Aerosol Sci 42:285–294CrossRefGoogle Scholar
  2. Amato I, Baudrocco F, Martorana D (1976) Evaluation of freeze drying and spray drying processes for preparing transparent alumina. Mater Sci Eng 26:73–78CrossRefGoogle Scholar
  3. Antonyuk S, Tomas J, Heinrich S, Mörl L (2005) Breakage behaviour of spherical granulates by compression. Chem Eng Sci 60:4031–4044CrossRefGoogle Scholar
  4. Barekar NS, Tzamtzis S, Hari Babu N, Fan Z, Dhindaw BK (2009) Processing of ultrafine-size particulate metal matrix composites by advanced shear technology. Metall Mater Trans A 40A:691–701CrossRefGoogle Scholar
  5. Barrett EP, Joyner LG, Halenda PP (1951) The determination of pore volume and area distributions in porous substances. I. Computations from nitrogen isotherms. J Am Chem Soc 73:373–380CrossRefGoogle Scholar
  6. Bertrand G, Roy P, Filiatre C, Coddet C (2005) Spray-dried ceramic powders: a quantitative correlation between slurry characteristics and shapes of the granules. Chem Eng Sci 60:95–102CrossRefGoogle Scholar
  7. Binner JGP, Annapoorani K, Santacruz I (2006) Patent No. WO 2006/136780 A2, 28 Dec 2006Google Scholar
  8. Boulch F, Schouler MC, Donnadieu P, Chaix JM, Djurado E (2001) Domain size distribution of Y-TZP nano-particles using XRD and HRTEM. Image Anal Stereol 20:157–161CrossRefGoogle Scholar
  9. Cellard A, Zenati R, Garnier V, Fantozzi G, Baret G (2007) Optimization of chromium oxide nanopowders dispersion for spray-drying. J Eur Ceram Soc 27:1017–1021CrossRefGoogle Scholar
  10. Chen G, Wang W (2007) Role of freeze drying in nanotechnology. Dry Technol 25:29–35CrossRefGoogle Scholar
  11. Coury JR, Aguiar ML (1995) Rupture of dry agglomerates. Powder Technol 85:37–43CrossRefGoogle Scholar
  12. Ewais E, Zaman AA, Sigmund W (2002) Temperature induced forming of zirconia from aqueous slurries: mechanism and rheology. J Eur Ceram Soc 22:2805–2812CrossRefGoogle Scholar
  13. Fengqiu T, Xiaoxian H, Yufeng Z, Jingkun G (2000) Effect of dispersants on the surface chemical properties of nano-zirconia suspensions. Ceram Int 26:93–97CrossRefGoogle Scholar
  14. Garvie RC, Hannink RH, Pascoe RT (1975) Ceramic steel? Nature 258:703–704CrossRefGoogle Scholar
  15. Gregg SJ, Sing KSW (1982) Adsorption, surface area and porosity, 2nd edn. Academic Press, London, pp 173–194Google Scholar
  16. Kendall K (1988) Agglomerate strength. Powder Metall 31:28–31Google Scholar
  17. Kendall K, Weihs TP (1992) Adhesion of nanoparticles within spray-dried agglomerates. J Phys D 25:A3–A8CrossRefGoogle Scholar
  18. Li C, Akinc M (2005) Role of bound water on the viscosity of nanometric alumina suspensions. J Am Ceram Soc 88:1448–1454CrossRefGoogle Scholar
  19. Lukasiewicz SJ (1989) Spray-drying ceramic powders. J Am Ceram Soc 72:617–624CrossRefGoogle Scholar
  20. Mahdjoub H, Roy P, Filiatre C, Betrand C, Coddet G (2003) The effect of the slurry formulation upon the morphology of spray-dried yttria stabilised zirconia particles. J Eur Ceram Soc 23:1637–1648CrossRefGoogle Scholar
  21. Marinho B, Ghislandi M, Tkalya E, Koning CE, With G (2012) Electrical conductivity of compacts of graphene, multi-wall carbon nanotubes, carbon black, and graphite powder. Powder Technol 221:351–358CrossRefGoogle Scholar
  22. Moritz T, Nagy A (2002) Preparation of super soft granules from nanosized ceramic powders by spray freezing. J Nanoparticle Res 4:439–448CrossRefGoogle Scholar
  23. Moritz T, Nagy A (2004) Spray freeze granulates—from lab scale to pilot production presented at 7th international conference on nanostructured materials, WiesbadenGoogle Scholar
  24. Njiwa ABK, Aulbach E, Rodel J (2006) Mechanical properties of dry-pressed powder compacts: case study on alumina nanoparticles. J Am Ceram Soc 89:2641–2644CrossRefGoogle Scholar
  25. Park BD, Smith DM, Thoma SG (1993) Determination of agglomerate strength distributions, part 4. Analysis of multimodal particle size distributions. Powder Technol 76:125–133CrossRefGoogle Scholar
  26. Pyda W, Gani MSJ (1995) Microstructural and mechanical properties of spherical zirconia-yttria granules. J Mater Sci 30:2121–2129CrossRefGoogle Scholar
  27. Raghupathy BPC, Binner JGP (2011) Spray granulation of nanometric zirconia particles. J Am Ceram Soc 94:139–145CrossRefGoogle Scholar
  28. Rumpf H (1962) Strength of granules and agglomerates. In: Knepper WA (ed) Agglomeration. Wiley-Interscience, New York, pp 379–418Google Scholar
  29. Santacruz MI, Annapoorani K, Binner JGP (2008) Preparation of high solids content nano zirconia suspensions. J Am Ceram Soc 91:398–405CrossRefGoogle Scholar
  30. Schneider LCR, Cocks ACF, Apostolopoulos A (2005) Comparison of filling behaviour of metallic, ceramic, hardmetal and magnetic powders. Powder Metall 48:77–84CrossRefGoogle Scholar
  31. Song J, Evans JRG (1994) A die pressing test for the estimation of agglomerate strength. J Am Ceram Soc 77:806–814CrossRefGoogle Scholar
  32. Tallón C, Moreno R, Nieto MI (2006) Synthesis of γ-Al2O3 nanopowders by freeze-drying. Mater Res Bull 41:1520–1529CrossRefGoogle Scholar
  33. Tan O (2004) Spray drying dielectric ceramics. Am Ceram Soc Bull 83:12–14CrossRefGoogle Scholar
  34. Tsetsekou A, Agrafiotis C, Leon A, Milias I (2001) Optimisation of the rheological properties of alumina slurries for ceramic processing applications, part II: spray drying. J Eur Ceram Soc 21:493–506CrossRefGoogle Scholar
  35. Uchida N, Hiranami T, Tanaka S, Uematsu K (2002) Spray freeze dried granules for ceramics fabrication. Am Ceram Soc Bull 81:57–60Google Scholar
  36. Walker JS Jr, Reed WJ (1999) Influence of slurry parameters on the characteristics of spray dried granules. J Am Ceram Soc 82:1711–1719CrossRefGoogle Scholar
  37. Wu CY, Dihoru L, Cocks ACF (2003) The flow of powders into simple and stepped dies. Powder Technol 134:24–39CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2012

Authors and Affiliations

  1. 1.Center for Nanotechnology ResearchVIT UniversityVelloreIndia
  2. 2.Department of MaterialsLoughborough UniversityLoughboroughUK

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