Abstract
Bu çalışmada, titanyum dioksit tozunun slip döküm tekniği ile şekillendirilmesi amaçlanmıştır. Deneysel çalışmalar esas olarak üç aşamadan oluşmaktadır. İlk olarak, hacimce % 2’lik TiO2 süspansiyonları kullanılarak sedimentasyon deneyleri yapılmıştır. İkinci aşamada, dispersiyon şartlarında TiO2 slip çamurları hazırlanmıştır ve daha sonra alçı kalıplarda şekillendirilmiştir. Şekillendirilen numunelerin sinterleme işlemi 1300, 1400 ve 1500°C’de 2 saat süre ile yapılmıştır. Son olarak, küçülme, Arşimed ve eğme dayanımı testleri, Mikroyapı (SEM) ve faz (XRD) analizleri uygulanmıştır. TiO2 tozuna ait süspansiyonların sedimentasyon testleri zpc noktasının (zero point of charge) yaklaşık olarak pH = 1-2’de olduğunu göstermiştir. Üç farklı sıcaklıkta sinterlenen numunelerin XRD paternleri sadece rutil fazına ait pikleri göstermiştir. Sinterlenmiş numunelerin pik şiddetlerinde çok küçük bir fark vardır. Titanyum dioksit içeren sıvı faz oluşumu pik şiddetlerinde bir düşüşe sebep olmuş olabilir. Sonuç olarak, sinterleme sıcaklığının artması toplam gözenek değerlerinde bir düşüşe ve pişme küçülmesi, kapalı porozite, görünür yoğunluk, bulk yoğunluk ve eğme dayanımında bir artışa sebep olmuştur. Su emme değeri %5.24'den %1.96'ya düşmüştür. Görünür gözeneklilik %18.03'ten %7.12'ye düşmüştür. Pişme küçülmesi oranı %8.70'den %11.30'a yükselmiştir. Bulk yoğunluk 3.24'ten 3.64 gr/cm3'e yükselmiştir. Üç nokta eğme dayanımı, artan sinterleme sıcaklığı ile 399.36 kg/cm2'den 566.33 kg/cm2'ye yükselmiştir.
References
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- Cesarano, J., Aksay, I.A. and Bleier, A. (1988). Stability of aqueous α-Al2O3 suspensions with poly(methacrylic acid) polyelectrolyte. Journal American Ceramics Society, 71(4), 250-255. https://doi.org/10.1111/j.1151-2916.1988.tb05855.x
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- Fujishima, A. and Zhan, X. (2006). Titanium dioxide photocatalysis: present situation and future approaches. Comptes Rendus Chimie, 9, 750-760. https://doi.org/10.1016/j.crci.2005.02.055
- Jingxian, Z., Dongliang, J., Weisensel, L. and Greil, P. (2004). Binary solvent mixture for tape casting of TiO2 sheets. Journal of European Ceramic Society, 24, 147-155. https://doi.org/10.1016/S0955-2219(03)00340-6
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Abstract
In this study, shaping of titanium dioxide powders using slip casting method was aimed. Experimental work essentially includes three stages. Initially, settling experiments were carried out using 2 vol. % TiO2 suspensions. In the second stage TiO2 slip was prepared at dispersion condition (pH = 7.0) and then shaped using plaster mould. The sintering process of shaped samples were carried out at 1300, 1400 and 1500°C. Finally, shrinkage, Archimedes and flexural strength tests, microstructure (SEM) and phase analysis (XRD) were performed. Settling experiments tests for the powder of TiO2 suspensions showed that the zpc (zero point of charge) is at approximately pH = 1-2. XRD patterns showed only rutile phase peaks for the samples sintered at three different temperatures. There is a small difference between the peak intensities of the sintered samples. Liquid phase formation containing titanium dioxide may have caused a decrease in peak intensities. Consequently, increasing the sintering temperature resulted in a decrease in total porosity, and an increase in firing shrinkage, closed porosity, apparent density, bulk density and bending strength values. Water absorption decreased from 5.24% to 1.96%. Apparent porosity decreased from 18.03% to 7.12%. Firing shrinkage increased from 8.70% to 11.30%. Bulk density increased from 3.24 to 3.64 gr/cm3. Three point bending strength increased from 399.36 kg/cm2 to 566.33 kg/cm2 with the increasing sintering temperature.
References
- Ceramic Industry (1999 January). ISSN 0009-0220.
- Cesarano, J., Aksay, I.A. and Bleier, A. (1988). Stability of aqueous α-Al2O3 suspensions with poly(methacrylic acid) polyelectrolyte. Journal American Ceramics Society, 71(4), 250-255. https://doi.org/10.1111/j.1151-2916.1988.tb05855.x
- Cesarano, J. and Aksay, I.A. (1988). Processing of highly concentrated aqueous α-alumina suspensions stabilized with polyelectrolytes. Journal American Ceramics Society, 71(12), 1062-1067. https://doi.org/10.1111/j.1151-2916.1988.tb05792.x
- Dutta, K.P., Ray, A.K., Sharma, V.K. and Millero, F.J. (2004). Adsorbtion of arsenate and arsenite on titanium dioxide suspensions. Journal of Colloid and Inteface Science, 278, 270-275. https://doi.org/10.1016/j.jcis.2004.06.015
- Fujishima, A. and Zhan, X. (2006). Titanium dioxide photocatalysis: present situation and future approaches. Comptes Rendus Chimie, 9, 750-760. https://doi.org/10.1016/j.crci.2005.02.055
- Jingxian, Z., Dongliang, J., Weisensel, L. and Greil, P. (2004). Binary solvent mixture for tape casting of TiO2 sheets. Journal of European Ceramic Society, 24, 147-155. https://doi.org/10.1016/S0955-2219(03)00340-6
- Science.gov (1981 July). Oxides of titanium and chromium. Engineering property date on selected ceramics, Volume III, Single Oxides. Metals and Ceramics Information Center, Battelle Columbus Laboratories, Ohio, USA.
- Wu, C., Yue, Y., Deng, X., Hua, W. and Gao, Z. (2004). Investigation on the synergetic effect between anatase and rutile nano particles in gas-phase photocatalytic oxidation. Catalysis Today, 93-95, 863-869. https://doi.org/10.1016/j.cattod.2004.06.087
Details
| Primary Language | English |
|---|---|
| Subjects | Engineering |
| Journal Section | Articles |
| Authors | |
| Publication Date | April 1, 2020 |
| Published in Issue | Year 2020 Ejosat Special Issue 2020 (ARACONF) |
