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Spray Freeze Granulation of Submicrometre α-Alumina Using Ultrasonication
S. Ghanizadeh1, P. Ramanujam1, B. Vaidhyanathan1, J. Binner1,2
1 Department of Materials, Loughborough University, Loughborough, LE11 3TU, UK
2 School of Metallurgy and Materials, College of Engineering and Physical Sciences, University of Birmingham, Edgbaston, Birmingham, B12 2TT, UK.
received August 25, 2016, received in revised form November 12, 2016, accepted November 22, 2016
Vol. 7, No. 4, Pages 455-462 DOI: 10.4416/JCST2016-00078
Abstract
Granulation is a key factor towards improvement of the flowability of fine ceramic powders to make them suitable for industrial dry pressing. Controlled granulation of fine alumina particles with a primary particle size of ∼ 150 nm was carried out using spray-freeze drying, which led to the production of flowable granules with high crushability. The fracture surface of uniaxially die-pressed green bodies made from granules with density values of ≥ 50 % of theoretical showed a uniform microstructure. Sintering experiments were performed using conventional single- and two-stage radiant heating methods followed by density and grain size measurement and characterisation of the final dense compacts to study the efficiency of two-stage sintering in grain growth elimination. The results have been compared with those of alumina bodies prepared using similar suspension by the slip-casting route.
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Keywords
Keywords: Alumina, granulation, spray-freeze drying, two-stage sintering
References
1 Krell, A., Blank, P.: The influence of shaping method on the grain size dependence of strength in dense submicrometre alumina, J. Eur. Ceram. Soc., 16, [11], 1189 – 1200, (1996).
2 Ghanizadeh, S., Bao, X., Vaidhyanathan, B., Binner, J.: Synthesis of nano α-alumina powders using hydrothermal and precipitation routes: A comparative study, Ceram. Int., 40, [1], 1311 – 1319, (2013).
3 Krell, A., Klimke, J., Hutzler, T.: Transparent compact ceramics: inherent physical issues, Opt. Mater., 31, [8], 1144 – 1150, (2009).
4 Krell, A.: Improved hardness and hierarchic influences on wear in submicron sintered alumina, Mater. Sci. Eng. A, 209, [1], 156 – 163, (1996).
5 Mayo, M.: Processing of nanocrystalline ceramics from ultrafine particles, Int. Mater. Rev., 41, [3], 85 – 115, (1996).
6 Binner, J., Vaidhyanathan, B.: Processing of bulk nanostructured ceramics, J. Eur. Ceram. Soc., 28, [7], 1329 – 1339, (2008).
7 Song, J.H., Evans, J.R.G.: A die pressing test for the estimation of agglomerate strength, J. Am. Ceram. Soc., 77, [3], 806 – 814, (1994).
8 Lukasiewicz, S.J.: Spray-Drying ceramic powders, J. Am. Ceram. Soc., 72, [4], 617 – 624, (1989).
9 Raghupathy, B.P.C., Binner, J.G.P.: Spray granulation of nanometric zirconia particles, J. Am. Ceram. Soc., 94, [1], 42 – 48, (2011).
10 Balasubramanian, S., Shanefield, D.J., Niesz, D.E.: Effect of externally applied plasticizer on compaction behavior of spray-dried powders, J. Am. Ceram. Soc., 85, [4], 749 – 754, (2002).
11 Moritz, T., Nagy, A.: Preparation of super soft granules from nanosized ceramic powders by spray freezing, J. Nanopart. Res., 4, [5], 439 – 448, (2002).
12 Binner, J., Vaidhyanathan, B., Paul, A., Annaporani, K., Raghupathy, B.: Compositional effects in nanostructured yttria partially stabilized zirconia, Int. J. Appl. Ceram. Tec., 8, [4], 766 – 782, (2011).
13 Binner, J., Annapoorani, K., Vaidhyanathan, B.: Spray freeze granulation of nano powders for die pressing, Adv. Sci. Tech., 63, 1 – 6, (2011).
14 Lin, F.J.T., Jonghe, L.C., Rahaman, M.N.: Microstructure refinement of sintered alumina by a two-step sintering technique, J. Am. Ceram. Soc., 80, [9], 2269 – 2277, (1997).
15 Chen, I.W., Wang, X.H.: Sintering dense nanocrystalline ceramics without final-stage grain growth, Nature, 404, [6774], 168 – 171, (2000).
16 Wang, X., Chen, P., Chen, I.: Two-step sintering of ceramics with constant grain-size, I. Y2O3, J. Am. Ceram. Soc., 89, [2], 431 – 437, (2006).
17 Richerson, D.: Modern ceramic engineering: properties, processing, and use in design. CRC 2005.
18 Shen, Z., Johnsson, M., Zhao, Z., Nygren, M.: Spark plasma sintering of alumina, J. Am. Ceram. Soc., 85, [8], 1921 – 1927, (2002).
19 Bodišová, K., Galusek, D., Švančárek, P., Pouchlý, V., Maca, K.: Grain growth suppression in alumina via doping and two-step sintering, Ceram. Int., 41, [9], 11975 – 11983, (2015).
20 Zhang, Y., Binner, J., Rielly, C., Vaidhyanathan, B.: Comparison of spray freeze dried nanozirconia granules using ultrasonication and twin-fluid atomisation, J. Eur. Ceram. Soc., 34, [4], 1001 – 1008, (2014).
21 Mendelson, M.I.: Average grain size in polycrystalline ceramics, J. Am. Ceram. Soc., 52, [8], 443 – 446, (1969).
22 Ramanujam, P., Vaidhyanathan, B., Binner, J., Ghanizadeh, S., Spacie, C.: Solvothermal nanoYAG synthesis: mechanism and particle growth kinetics, J. Supercrit. Fluids, 107, 433 – 440, (2016).
23 Hanaor, D., Michelazzi, M., Leonelli, C., Sorrell, C.C.: The effects of carboxylic acids on the aqueous dispersion and electrophoretic deposition of ZrO2, J. Eur. Ceram. Soc., 32, [1], 235 – 244, (2012).
24 Binner, J., Annapoorani, K., Paul, A., Santacruz, I., Vaidhyanathan, B.: Dense nanostructured zirconia by two stage conventional/hybrid microwave sintering, J. Eur. Ceram. Soc., 28, [5], 973 – 977, (2008).
25 Bodišová, K., Šajgalík, P., Galusek, D., Švančárek, P.: Two-stage sintering of alumina with submicrometer grain size, J. Am. Ceram. Soc., 90, [1], 330 – 332, (2007).
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