Novel Direct Coagulation Casting of Alumina Suspensions Using Y3+-Ion Releasing Substances as Coagulant

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Abstract:

Direct coagulation casting (DCC) is a relatively new ceramic near-net-shape forming process which can form homogeneous ceramic green body with complex shape and high density. Direct coagulation casting of aqueous alumina slurries by adding Y3+ ions, which have been frequently used as additive for the sintering of alumina ceramics, were studied. Two different kinds of Y3+-ion releasing substances, Y2O3 powder and Y(NO3)3, were used as coagulants and were introduced into stabilized alumina suspensions directly after dispersing. Compared with that of Y2O3 powder, both the coagulation time and the added amount required for a reasonable shaping were significantly reduced for using Y(NO3)3 as coagulant. The effects of the two coagulants on the properties of the consolidated green bodies and sintered ceramics were studied. The mechanisms of coagulation induced by the addition of Y3+-ions were discussed on the basis of interactions between Y3+ ions and the added polyelectrolyte dispersant.

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Key Engineering Materials (Volumes 602-603)

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164-169

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March 2014

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© 2014 Trans Tech Publications Ltd. All Rights Reserved

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[1] L.J. Gauckler, T.J. Graule, F.H. Baader, Ceramic Forming Using Enzyme Catalyzed Reactions, Mater. Chem. Phy. 61(1) (1999) 78-102.

DOI: 10.1016/s0254-0584(99)00117-0

Google Scholar

[2] P.B. LonG, S. Isabel, Rheological Characterization of Electrosterically Dispersed Alumina Suspensions During In Situ Cagulation, J. Am. Ceram. Soc. 89(3) (2000) 863-868.

Google Scholar

[3] T.J. Graule F.H. Baader, L.J. Gauckler, Casting Uniform Ceramics with Direct Coagulation, Chem. Tech. 25(6) (1995) 31-37.

Google Scholar

[4] F.H. Baader, T.J. Graule, L.J. Gauckler, Direct coagulation casting –A New Green Shaping Technique. Part I. Processing Principles, Ind. Ceram. 16(1) (1996) 31-36.

Google Scholar

[5] F.H. Baader, T.J. Graule, L.J. Gauckler, Direct coagulation casting –A New Green Shaping Technique. Part II. Application to Alumina, Ind. Ceram. 16(1) (1996) 36-40.

Google Scholar

[6] B. Blazer, M.K.M. Hruschka, L.J. Gauckler, Coagulation Kinetics and Mechanical Behavior of Wet Alumina Green Bodies Produced via DCC, J. Colloid Interf. Sci. 216(2) (1999) 379-386.

DOI: 10.1006/jcis.1999.6293

Google Scholar

[7] D. Hesselbarth, E. Tervoort, C. Urban, Mechanical properties of coagulated wet works with alkali swellable thickness , J. Am. Ceram. Soc. 84 (2001) 1689-1695.

DOI: 10.1111/j.1151-2916.2001.tb00900.x

Google Scholar

[8] T. Kosmac, N. Novak,P. Meier, Hydrolysis-Assisted Solidification (HAS): A New Setting Concept for Ceramic Net-shaping, J. Eur. Ceram. Soc. 17(2-3) (1997) 427-432.

DOI: 10.1016/s0955-2219(96)00175-6

Google Scholar

[9] P. Kuttan, S.K. Chandrashekhar, Effect of Concentration of Ammonium Poly(acrylae) Dispersant and MgO on Coagulation Characteristics of Aqueous Alumina Direct Coagulation Casting Slurries, J. Am. Ceram. Soc. 91(6) (2008) 1933-(1938).

DOI: 10.1111/j.1551-2916.2008.02395.x

Google Scholar

[10] P. Kuttan, R. Sooraj, M. Anand, Novel Coagulation Method for Direct Coagulation Casting of Aqueous Alumina Slurries Prepared Using a Poly(Acrylate) Dispersant, J. Am. Ceram. Soc. 91(2) (2008) 615-619.

DOI: 10.1111/j.1551-2916.2007.02122.x

Google Scholar

[11] K. Prabhakaran, K. Joseph, R. Sooraj, Magnesia Induced Coagulation of Aqueous PZT Powder Suspentions for Direct Coagulation Casting, J. Am. Ceram. Soc. 36 (2010) 2095-2101.

DOI: 10.1016/j.ceramint.2010.05.020

Google Scholar

[12] K. Prabhakaran, R. Sooraj, C.S. Kumbhar, HeterocoagulationMoulding of Alumina Ower Suspensions Prepared Using Citrate Dispersant , J. Am. Ceram. Soc. 36 (2010) 1-8.

DOI: 10.1016/j.ceramint.2009.04.030

Google Scholar

[13] J. Xu,N. Wen H.X. Li, Direct Coagulation Casting of Alumina Suspension by High Valence Counter Ions Using Ca (IO3)2 as Coagulating Agent, J. Am. Ceram. Soc. 95(8) (2012) 2525-2530.

DOI: 10.1111/j.1551-2916.2012.05239.x

Google Scholar

[14] J. Xu, N. Wen, F. Qi, Direct Coagulation Casting of Positively Charged Alumina Suspension by Controlled Release of High Valence Counter Ions from Calcium Phosphate, J. Am. Ceram. Soc. 95(7) (2012) 2155-2160.

DOI: 10.1111/j.1551-2916.2012.05182.x

Google Scholar

[15] J.L. Yang, J. Xu, N. Wen, Direct Coagulation Casting of Alumina Suspension via Controlled Release of High Valence Counterions from Thermo-sensitive Liposomes, J. Am. Ceram. Soc. 96(1) (2013) 62-67.

DOI: 10.1111/jace.12063

Google Scholar