Fabrication and Characterization of Mullite Reinforced CaO Added ZrO2 Ceramics

Abstract

In this study, mullite (3Al2O3.2SiO2) and 11 mol % calcia added zirconia (11 mol % CaO - 89 mol % ZrO2) ceramic powders were synthesized by conventional ceramic production processing route. The mixtures were prepared by mechanical alloying method in acetone environment with zirconia ball mill. The powders were dried in oven at 110 ºC for 24 hours before mixing. Mullite (3Al2O3.2SiO2) and 11 mol% calcia added zirconia (CaO-ZrO2) ceramic powders were synthesized by reaction sintering from the powders made up of stoichiometric proportions of Al2O3, SiO2, CaO and ZrO2 powders after being homogenized in acetone environment in ball mills. Mullite (3Al2O3.2SiO2) and 11 mol% calcia added zirconia (CaO-ZrO2) ceramic powders were synthesized in air at 1600 oC for 3 h and 1300 oC for 2 h, respectively. Then, the ceramic phases formed were made ready to form ceramic - ceramic composites by crushing, grinding and sieving processes. Then 0 and 10% by weight mullite (M) added calcia doped zirconia (CaZ) mixtures were prepared by powder metallurgy method. The prepared mixtures were wet milled with zirconia ball mill for 24 h and sieved. After drying, the powders were compacted to preforms of 56x12x10 mm by uniaxial pressing at 200 MPa. The green compacts were sintered at 1500-1600 oC for 1-5 h in air conditions using a heating rate of 5 oC min-1 in a high temperature furnace. Then, microstructure (SEM), phase analysis (XRD), mechanical (hardness, 3-point bending and wear) and physical properties (% shrinkage, water absorption, porosity and density) tests were performed on the mullite added calcia doped zirconia ceramic composites. In this study, whether there is a phase change in the ZrO2 - CaO mixture at high sintering temperatures and the effect of mullite additive on the properties of this mixture was investigated. The data obtained were presented in graphs and tables and their comments were made.

Keywords

• Zirconia
• Mullite
• Calcia
• Characterization
• Wear

Mullit Takviyeli CaO Katkılı ZrO2 Seramiklerinin İmalatı ve Karakterizasyonu

Abstract

Bu çalışmada, mullit (3Al2O3.2SiO2) ve %11 mol kalsiyum oksit katkılı zirkonya (%11 mol CaO - %89 mol ZrO2) seramik tozları geleneksel seramik üretim yöntemi ile sentezlenmiştir. Karışımlar, zirkonya bilyalı değirmende aseton ortamında mekanik alaşımlama yöntemiyle hazırlanmıştır. Tozlar karıştırılmadan önce 110 ºC'de 24 saat etüvde kurutulmuştur. Al2O3, SiO2, CaO ve ZrO2 tozlarının stokiyometrik oranlarından oluşan tozların aseton ortamında bilyeli değirmende homojenize edildikten sonra geleneksel sinterleme yöntemiyle Mullit (3Al2O3.2SiO2) ve %11 mol kalsiyum oksit katkılı zirkonya (CaO-ZrO2) seramik tozları sentezlenmiştir. Mullit ve %11 mol kalsiyum oksit katkılı zirkonya seramik tozları sırasıyla 1600 oC'de 3 saat ve 1300 oC'de 2 saat sentezlenmiştir. Daha sonra oluşan seramik fazlar kırma, öğütme ve eleme işlemleri ile seramik - seramik kompozitleri oluşturmaya hazır hale getirilmiştir. Daha sonra ağırlıkça %0 ve %10 mullit (M) takviyeli kalsiyum oksit katkılı zirkonya (CaZ) karışımları toz metalurjisi yöntemiyle hazırlanmıştır. Hazırlanan karışımlar zirkonya bilyalı değirmende 24 saat yaş öğütülmüş ve elenmiştir. Kurutulduktan sonra, tozlar 200 MPa'da tek eksenli presleme ile 56x12x10 mm'lik preformlara sıkıştırılmıştır. Devamında, yüksek sıcaklıklı bir fırında 5 oC/dak ısıtma hızı kullanılarak hava koşullarında 1500-1600 oC'de 1-5 saat sinterlenmiştir. Daha sonra mullit takviyeli kalsiyum oksit katkılı zirkonya seramik kompozitler üzerinde mikroyapı (SEM), faz analizi (XRD), mekanik (sertlik, 3 nokta eğme ve aşınma) ve fiziksel özellikler (% küçülme, su emme, gözeneklilik ve yoğunluk) testleri yapılmıştır. Bu çalışmada, yüksek sinterleme sıcaklıklarında ZrO2 - CaO karışımında faz değişimi olup olmadığı ve mullit katkı maddesinin bu karışımın özelliklerine etkisi araştırılmıştır. Elde edilen veriler grafik ve tablolar halinde sunulmuş ve yorumları yapılmıştır.

Keywords

• Zirkonya
• Mullit
• Kalsiyum oksit
• Karakterizasyon
• Aşınma

References

1. Boyraz, T. (2008). An investigation on physical and electrical properties of CaO/MgO-stabilized zirconia ceramics formed with different methods. Istanbul Technical University / Graduate School of Natural and Applied Sciences, (Doctoral dissertation). 150p.
2. Pekdemir, A.D. (2018). Preparation and characterization of boron carbide at low-temperature from boric acid and polyols. Ankara University / Graduate School of Natural and Applied Sciences, (Doctoral dissertation). 178p
3. Ceylan, A. (2006). The production of functionally graded SiAlON ceramics by tape casting method. Anadolu University / Graduate School of Natural and Applied Sciences, (Doctoral dissertation). 204p.
4. Abi, C.B. (2009). An investigation on fracture toughness of traditional and technical ceramics. Afyon Kocatepe University / Graduate School of Natural and Applied Sciences, (Doctoral dissertation). 194p.
5. Hafızoğlu M. A., Boyraz, T. and Akkuş, A. (2021). Fabrication, characterization and wear properties of mullite reinforced silica-doped zirconia ceramic composites. 4. International Conference on Materials Science, Mechanical and Automotive Engineerings and Technology (IMSMATEC'21).
6. Hafızoğlu M. A., Akkuş, A. and Boyraz, T. (2021). Fabrication, characterization and wear properties of mullite reinforced Al2O3-doped ZrO2 ceramic composites. Global Conference on Engineering Research (GLOBCER’21).
7. Hafızoğlu M. A., Boyraz, T. and Akkuş, A. (2021). Fabrication and characterization of mullite reinforced TiO2 added ZrO2 ceramics. International Joint Science Congress of Materials and Polymers (ISCMP’21).
8. Cutler, R. A., Reynolds, J. R. and Jones, A. (1992). Sintering and characterization of polycrystalline monoclinic, tetragonal, and cubic zirconia. Journal of the American Ceramic Society, 75(8), 2173-2183.

9. Boyacıoğlu, T. (2007). Improvement of room temperature mechanical properties of various amount of metal oxide doping cubic zirconia (c-ZrO2) used as electrolyte material for solid oxide fuel cells. Gazi University / Graduate School of Natural and Applied Sciences, (Master's thesis). 123p.
10. Boyraz, T. (1998). Dental porcelain powders. Sakarya University / Graduate School of Natural and Applied Sciences, (Master's thesis). 131p.
11. Liu, P. F., Li, Z., Xiao, P. et al. (2018). Microstructure and mechanical properties of in-situ grown mullite toughened 3Y-TZP zirconia ceramics fabricated by gelcasting. Ceramics International, 44(2), 1394-1403.
12. Eichler, J., Rödel, J. et al. (2007). Effect of grain size on mechanical properties of submicrometer 3Y‐TZP: fracture strength and hydrothermal degradation. Journal of the American Ceramic Society, 90(9), 2830-2836.
13. Sun, J., Gao, L., Iwasa, M., Nakayama, T. and Niihara, K. (2005). Failure investigation of carbon nanotube/3Y-TZP nanocomposites. Ceramics International, 31(8), 1131-1134.
14. El Ouatib, R., Guillemet, S., Durand, B. et al. (2005). Reactivity of aluminum sulfate and silica in molten alkali-metal sulfates in order to prepare mullite. Journal of the European Ceramic Society, 25(1), 73-80.
15. Kucuk, I. and Boyraz, T. (2019). Structural and mechanical characterization of mullite and aluminium titanate reinforced yttria stabilized zirconia ceramic composites. Journal of Ceramic Processing Research, 20(1), 73-79.
16. Kumar, P., Nath, M. et al. (2015). Enhancement of thermal shock resistance of reaction sintered mullite–zirconia composites in the presence of lanthanum oxide. Materials Characterization, 101, 34-39.
17. Roy, J., Das, S. and Maitra, S. (2015). Solgel‐processed mullite coating—a review. International Journal of Applied Ceramic Technology, 12, E71-E77.
18. Denry, I. and Kelly, J. R. (2008). State of the art of zirconia for dental applications. Dental materials, 24(3), 299-307.
19. Çitak, E. and Boyraz, T. (2014). Microstructural characterization and thermal properties of aluminium titanate/YSZ Ceramics. Acta Physica Polonica A, 125(2), 465-468.
20. Önen, U. and Boyraz, T. (2014). Microstructural characterization and thermal properties of aluminium titanate/spinel ceramic matrix composites. Acta Phys. Pol. A, 125(2), 488-490.
21. Sacli, M., Onen, U. and Boyraz, T. (2015). Microstructural characterization and thermal properties of aluminium titanate/porcelain ceramic matrix composites. Acta Physica Polonica A, 127(4), 1133-1135.
22. Boyraz, T. and Akkuş, A. (2021). Investigation of wear properties of mullite and aluminium titanate added porcelain ceramics, Journal of Ceramic Processing Research. Vol. 22, No. 2, pp. 226-231.
23. Akkus, A. and Boyraz, T. (2018). Investigation of wear properties of CaO, MgO added stabilized zirconia ceramics produced by different pressing methods. J Ceram Process Res, 19(3), 249-52.
24. Kucuk, I., Boyraz, T. et al. (2018). Thermomechanical properties of aluminium titanate (Al2TiO5)-reinforced forsterite (Mg2SiO4) ceramic composites. Ceramics International, 44(7), 8277-8282.
25. Nath, S., Sinha, N., & Basu, B. (2008). Microstructure, mechanical and tribological properties of microwave sintered calcia-doped zirconia for biomedical applications. Ceramics International, 34(6), 1509-1520.
26. Yazıcı, E. G. (2013). Production and characterization of MgO partially stabilized zirconia dental ceramics. Afyon Kocatepe University / Graduate School of Natural and Applied Sciences, (Master's thesis). 127p.
27. Kumar, P., Nath, M., Ghosh, A., & Tripathi, H. S. (2016). Thermo-mechanical properties of mullite—zirconia composites derived from reaction sintering of zircon and sillimanite beach sand: Effect of CaO. Transactions of Nonferrous Metals Society of China, 26(9), 2397-2403.
28. Chandra, D., Das, G., & Maitra, S. (2015). Comparison of the Role of M g O and C a O Additives on the Microstructures of Reaction‐Sintered Zirconia–Mullite Composite. International Journal of Applied Ceramic Technology, 12(4), 771-782.