Light Metals 2012 pp 1385-1388 | Cite as
Effect of MnO2 Addition on Early-Stage Sintering Behavior and Properties of NiFe2O4 Ceramics
Abstract
The samples with small amounts of MnO2 (0, 0.5, 1.0, 2.5 wt%, respectively) were prepared via ball-milling process and two-step sintering process from commercial powders (i.e. Fe2O3, NiO and MnO2). Microstructure features, phase transformation, the early-stage sintering behavior and mechanical properties of Mn-doped NiFe2O4 samples have been investigated. Results indicate that the reduction of MnO2 into Mn2O3 and following the reduction of Mn2O3 into MnO existed in sintering process. No new phases are detected in the matrix, the crystalline structures of ceramic matrix are still NiFe2O4 spinel structure. MnO2 addition can promote the sintering process. The temperature for 1 wt% MnO2-doped samples to reach the maximum shrinkage rate is 59 °C lower than that of un-doped samples.
Keywords
NiFe2O4 Composite Ceramic MnO2 Addition Sintering Behavior Microstructure Mechanical PropertyPreview
Unable to display preview. Download preview PDF.
References
- 1.J.,Keniry, “The Economics of Inert Anodes and Wettable Cathodes for Aluminum Reduction Cells,” JOM, 5(53) (2001), 43–48.CrossRefGoogle Scholar
- 2.J. Ma et al., “Research on Preparation and Properties of 18MO-NiFe2O4 Composite Ceramic Inert Anodes,” Light Metals, 2010, 949–952.Google Scholar
- 3.L.J. Berchmans et al., “Evaluation of Mg2+-substituted NiFe2O4 as a Green Anode Material,” Mater. Lett, 58(2004), 1928–1933.CrossRefGoogle Scholar
- 4.J.H. Yang et al., “The Behavior and Improvement of SnO2-Based Inert Anodes in Aluminum Electrolysis,” Light Metals, 1993, 493–495.Google Scholar
- 5.S. P. Ray, R. A. Rapp, “Composition Suitable for Use as Inert Electrode Having Good Electrical Conductivity and Mechanical Properties,” US Patent: 4454015, 1984–02–08.Google Scholar
- 6.S.P. Ray, “Inert Anodes for Hall cells,” Light Metals, 1986, 287–298.Google Scholar
- 7.E. Olsen, and J. Thonstad, “Nickel Ferrite as Inert Anodes in Aluminum Electrolysis (part I): Material Fabrication and Preliminary Testing,” J. Appl. Electrochem., 29(1999), 293–299.CrossRefGoogle Scholar
- 8.J. Thonstad et al., Aluminium (3rd edition) MI. (Düsseldorf: Aluminium-Verlag, 2001), 328–338.Google Scholar
- 9.L.M. Zhang et al., Fundamentals of Materials Science (in Chinese), Wuhan University of Technology Press, 2008.Google Scholar
- 10.Z.G. Zhang et al., “Synthesis of NiFe2O4 Spinel Nanopowder via Low-Temperature Solid-State Reactions”, Journal of Northeastern University (Natural Science), 31(6) 2010, 868–871. (in Chinese)Google Scholar
- 11.J.H. Xi et al, “Effects of Addtive V2O5 on Sintering Mechanism and Properties of Nickel Ferrite,” Journal of the Chinese Ceramic Society, 33(6) 2005, 683–687. (in Chinese)Google Scholar
- 12.T.S. Zhang et al., “Sintering and Densification Behavior of Mn-doped CeO2,” Mat. Sci. Eng. B., 83 (2001), 235–241.CrossRefGoogle Scholar
- 13.J.A. Cerri et al., “Effect of Cobalt (II) Oxide and Manganese (IV) Oxide on Sintering of Tin(IV) Oxide,” J. Am. Ceram. Soc, 79(1996), 799–801.CrossRefGoogle Scholar
- 14.T.S. Zhang et al., “Sintering study on commercial CeO2 powder with small amount of MnO2 doping,” Mater. Lett, 57(2002), 507–512.CrossRefGoogle Scholar
- 15.H. Erkalfa, Z. Misirli, T. Baykara, “Densification of Alumina at 1250°C with MnO2 and TiO2 Additives,” Ceram. Int., 21(1995), 345–348.CrossRefGoogle Scholar