The Effects of Process Conditions on Improvement of the Compressive Strengths of Reticulated Porous Zirconia  
[PERSON]  
1 Powder and Ceramics Division, Korea Institute of Materials Science, 797 Changwondaero, Seongsan-gu, Changwon 51508, Korea, [EMAIL_ADDRESS] (S.L. ); [EMAIL_ADDRESS] (C.-Y.L. ); [EMAIL_ADDRESS] (J.L. ); [EMAIL_ADDRESS] (J.-H.S.) [PERSON]  
1 Powder and Ceramics Division, Korea Institute of Materials Science, 797 Changwondaero, Seongsan-gu, Changwon 51508, Korea, [EMAIL_ADDRESS] (S.L. ); [EMAIL_ADDRESS] (C.-Y.L. ); [EMAIL_ADDRESS] (J.L. ); [EMAIL_ADDRESS] (J.-H.S.) [PERSON]  
1 Powder and Ceramics Division, Korea Institute of Materials Science, 797 Changwondaero, Seongsan-gu, Changwon 51508, Korea, [EMAIL_ADDRESS] (S.L. ); [EMAIL_ADDRESS] (C.-Y.L. ); [EMAIL_ADDRESS] (J.L. ); [EMAIL_ADDRESS] (J.-H.S.) [PERSON]  
1 Powder and Ceramics Division, Korea Institute of Materials Science, 797 Changwondaero, Seongsan-gu, Changwon 51508, Korea, [EMAIL_ADDRESS] (S.L. ); [EMAIL_ADDRESS] (C.-Y.L. ); [EMAIL_ADDRESS] (J.L. ); [EMAIL_ADDRESS] (J.-H.S.) [PERSON]  
2 School of Materials Science and Engineering, Pusan National University, 2 Busandaehak-ro 63 beon-gil, Geumjeong-gu, Busan 46241, Korea  
applications of these materials, such as to advanced separation/filtration and dielectric materials that utilize reticulated porous ceramics. Zirconia is known as a typical ceramic material with relatively high mechanical strength and toughness, low thermal conductivity, and superior chemical and erosion resistance [11]. It is used in various industrial applications as an electronic and structural material. Moreover, zirconia with a porous structure has been applied to the biomedical field, with examples being bone scaffolding and implants due to its excellent biocompatibility [12]. Pure zirconia undergoes a phase transformation from monoclinic at room temperature to tetragonal at about 1173 \({}^{\circ}\)C, and then to cubic at approximately 2370 \({}^{\circ}\)C. During the phase transformation, there is a volume variation (about 5%) from tetragonal to monoclinic, which degrades the characteristics of this material. Therefore, pure zirconia requires the addition of a stabilizer oxide, leading to stabilized zirconia at room temperature. Stabilized zirconia can be prepared by adding various types of stabilizers (Y\({}_{2}\)O\({}_{3}\), MgO, CaO, and CeO). A common type is 3-5 mol% yttria-stabilized zirconia. In particular, 3 mol% yttria-stabilized zirconia is the most thermally stable type with the best tensile strength [13]. Porous zirconia is mainly manufactured by means of the sacrificial template method [6] and by direct forming [7]. When manufacturing porous zirconia using the sacrificial template method, it is difficult to control the pore characteristics, specifically the porosity, pore size, and pore structure, due to the uneven mixing of the pore-forming agents. When preparing porous zirconia using the direct forming method, the resulting closed pore structure limits applications that require an open pore structure. On the other hand, when seeking to produce porous zirconia with a cellular structure, the replica method is the only method that can be used [14]. However, one drawback of the replica method is the insufficient compressive strength resulting from the removal of the polymer template corresponding to the strut after a heat treatment compared to other methods (i.e., the direct forming and sacrificial template methods). Additionally, cracks can easily occur due to shrinkage arising during the sintering process. Therefore, this paper focuses on the manufacturing of a completely reticulated type of porous zirconia with excellent compressive strength by tailoring the process conditions. First, we optimize the viscosity of the zirconia slurry by tailoring the solid loading level, the particle size and the type of binder and dispersant used, as the viscosity of the ceramic slurry influences the coating state, where cracks, voids, and defects should be minimized.