Influence of Sintering Additives on the Porous Structure and Mechanical Properties of Porous Alumina
Main Article Content
Abstract
The aim of the present work is to investigate and to compare the influence of the two sintering additives $Cr_{2}O_{3}$ and $TiO_{2}$ on the porous structure and the mechanical properties of the sintered porous alumina. Alumina based porous ceramics were fabricated by sacrificial template technique via powder metallurgy route from alumina powder using ammonium bicarbonate $(NH_{4})HCO_{3}$ as the pore former. The results showed that the use of sintering additives led to a remarkble enhancement of the bonding between alumina particles hence the strength of the alumina based porous ceramics. Between the two sintering additives, $TiO_{2}$ was more effective in aiding sintering (densification) of alumina than $Cr_{2}O_{3}$. Consequently, the sintered porous alumina using $TiO_{2}$ as sintering additive has a smaller pore size, 190±30 µm compared to 220±40 µm of that with $Cr_{2}O_{3}$, and lower porosity. The porosity of the sintered samples increased with the concentration of the pore-forming agents and reaches the highest value of 79.3% and 82.6% corresponding to $TiO_{2}$ and $Cr_{2}O_{3}$ used. The mechanical strength of the porous alumina varied inversely with porosity.
Keywords
Porous alumina, Titanium dioxide, Chromium oxide, Sintering additive
Article Details
References
[1] E.C. Hammel, O.L.-R. Ighodaro, O.I. Okoli, Processing and properties of advanced porous ceramics: An application based review, Ceram. Int. 40 (2014) 15351-15370.
[2] I.Y. Guzman. Certain Principles of Formation of Porous Ceramic Structures. Properties and Applications (A Review), Glass Ceram. 60 (2003) 280-283.
[3] D. Li. M. Li, Porous Y2SiO5 Ceramic with Low Thermal Conductivity, J. Mater. Sci. Technol. 28 (2012) 799-802.
[4] A.R. Studart, U.T. Gonzenbach, E. Tervoort, L.J. Gauckler, Processing Routes to Macroporous Ceramics: A Review, J. Am. Ceram. Soc. 89 (2006) 1771-1789.
[5] E. Chevalier, D. Chulia, C. Pouget, M. Viana, Fabrication of porous substrates: a review of processes using pore forming agents in the biomaterial field, J. Pharm. Sci. 97 (2008) 1135-1154.
[6] T. Ohji, M. Fukushima, Macro-porous ceramics: processing and properties, Int. Mater. Rev. 57 (2012) 115-131.
[7] L.A. Xue, I.-W. Chen, Low-Temperature Sintering of Alumina with Liquid-Forming Additives, J. Am. Ceram. Soc. 74 (1991) 2011-2013.
[8] I.B. Cutler. C. Bradshaw, C.J. Christensen. E.P. Hyatt, Sintering of Alumina at Temperatures of $1400^{\circ}C$ and Below, J. Am. Ceram. Soc. 40 (1957) 134-139.
[9] Seung-Am Cho, F.J. Arenas, J. Ochoa, Densification and hardness of $Al_{2}O_{3}-Cr_{2}O_{3}$ system with and without Ti addition, Ceram. Int. (1990) 301-309.
[10] R. D. Bagley, I.B. Cutler and D. L. Johnson, Effect of $TiO_{2}$ on Initial Sintering of Al2O3, J. Am. Ceram. Soc. 53 (1970) 136-141.
[11] J.J. Kanga, B.S.Xub, H.D. Wang, C.B. Wanga, Influence of Spraying Parameters. on the Microstructure and Properties of Plasma-sprayed Al2O3/40%TiO2 Coating, Physics Procedia Vol. 50 (2013) 169-176.
[12] K.Q. Dang and M. Nanko, Effects of pressure and temperature on sintering of Cr-doped $Al_{2}O_{3}$ by pulsed electric current sintering process, IOP Conf. Series: Mater. Sci. and Eng. 20 (2011) 012004
[13] A. Azarniya, A. Azarniya, H. R. Hosseinia, Abdolreza Simchib, Mechanical and thermal properties of highly porous Al₂TiO5-Mullite ceramics, Ceram. Int., Vol. 42, Issue 2, Part B (2016) 3548-3555.
[2] I.Y. Guzman. Certain Principles of Formation of Porous Ceramic Structures. Properties and Applications (A Review), Glass Ceram. 60 (2003) 280-283.
[3] D. Li. M. Li, Porous Y2SiO5 Ceramic with Low Thermal Conductivity, J. Mater. Sci. Technol. 28 (2012) 799-802.
[4] A.R. Studart, U.T. Gonzenbach, E. Tervoort, L.J. Gauckler, Processing Routes to Macroporous Ceramics: A Review, J. Am. Ceram. Soc. 89 (2006) 1771-1789.
[5] E. Chevalier, D. Chulia, C. Pouget, M. Viana, Fabrication of porous substrates: a review of processes using pore forming agents in the biomaterial field, J. Pharm. Sci. 97 (2008) 1135-1154.
[6] T. Ohji, M. Fukushima, Macro-porous ceramics: processing and properties, Int. Mater. Rev. 57 (2012) 115-131.
[7] L.A. Xue, I.-W. Chen, Low-Temperature Sintering of Alumina with Liquid-Forming Additives, J. Am. Ceram. Soc. 74 (1991) 2011-2013.
[8] I.B. Cutler. C. Bradshaw, C.J. Christensen. E.P. Hyatt, Sintering of Alumina at Temperatures of $1400^{\circ}C$ and Below, J. Am. Ceram. Soc. 40 (1957) 134-139.
[9] Seung-Am Cho, F.J. Arenas, J. Ochoa, Densification and hardness of $Al_{2}O_{3}-Cr_{2}O_{3}$ system with and without Ti addition, Ceram. Int. (1990) 301-309.
[10] R. D. Bagley, I.B. Cutler and D. L. Johnson, Effect of $TiO_{2}$ on Initial Sintering of Al2O3, J. Am. Ceram. Soc. 53 (1970) 136-141.
[11] J.J. Kanga, B.S.Xub, H.D. Wang, C.B. Wanga, Influence of Spraying Parameters. on the Microstructure and Properties of Plasma-sprayed Al2O3/40%TiO2 Coating, Physics Procedia Vol. 50 (2013) 169-176.
[12] K.Q. Dang and M. Nanko, Effects of pressure and temperature on sintering of Cr-doped $Al_{2}O_{3}$ by pulsed electric current sintering process, IOP Conf. Series: Mater. Sci. and Eng. 20 (2011) 012004
[13] A. Azarniya, A. Azarniya, H. R. Hosseinia, Abdolreza Simchib, Mechanical and thermal properties of highly porous Al₂TiO5-Mullite ceramics, Ceram. Int., Vol. 42, Issue 2, Part B (2016) 3548-3555.