ZiRKON, KAOLiNiT, GiBSiT ve KOLEMANiT KARIŞIMINDAN MULLiT-ZiRKONYA KOMPOziTiN SENTEZi

Abstract

Bu cahsmada, zirkon, gibsit, kaolinit ve kolemanit hammaddelerinin belirli orandaki kansirrundan reaksiyon sinterlemesi yolu ile mullit-zirkonya kompoziti sentezlenrnistir. Kansim, agrrhkca 25% zirkon, 25% kaolinit, 40% gibsit ve 10% kolemanitten meydana gelrnistir. XRD analizlerine gore, 1450°C'de mullit ve monoklinik zirkonya ana piklerin yarunda az miktarda parcalanmayan zirkon ve kalsiyum silikat piklerine ait izlere rastlanrrustir. Zirkon 1500°C'de tamamen parcalanmisur. I 550°C' de 12 saat sinterlenen kansirnla, 1500°C'de sinterlenen kansirrun XRD patemleri karsilastinldrgmda mullit ve monoklinik zirkonyamn ana pikJerine ait siddetlerindeki az bir farkla benzerlik gorulrnustur.

Keywords

• Zirkon,Kaolinit,Gibsit,Kolemanit,Reaksiyon Sinterleme

SYNTHESIS OF MULLiTE-ziRCONiA COMPosiTE FROM ZiRCON, KAOLiNiTE, GiBBSiTE AND COLEMANiTE MiXTURES

Abstract

In the present study, mullite-zirconia composite was synthesized by reaction sintering a mixture of zircon. kaolinite. gibbsite and colemanite raw materials. The mixture consisted of 25 wt.% zircon. 25 wt.% kaolinite. 40 wt.% gibbsite and 10 wt.% colemanite. The XRO analysis of the mixture sintered at 1450°C showed the mullite and monoclinic zirconia as the major phases along with zircon and calcium silicate as secondary phases with their trace amount. whereas zircon phase disappeared completely at 1500°C. With the difference in the intensity of mullite and monoclinic zirconia. the mixture sintered at 1550°C exhibit analogous XRD pattern compared with the mixture sintered at 15000C for 12 h.

Keywords

• Zircon. Kaolinite
• Gibbsite
• Colernanlte
• Reaction Sintering

References

1. [1] Sainz, M.A., Serrano, F.J., Amigo, J.M., Bastida, J and Caballero, A. 2000. XRD microstructural analysis of mullites obtained from kaolinite-alumina mixtures. Journal of the European Ceramic Society. Vol. 20.403-412.
2. [2] Ebadzadeh, T. 2000. Reaction sintering of multicomponent mixtures for producing ceramics containing zirconia. Journal of the European Ceramic Society. Vol. 20. 725-729.
3. [3] Chen, c.v., Lan, O.S. and Tuan, W.H. 2000. Preparation of mullite by the reaction sintering of kaolinite and alumina. Journal of the European Ceramic Society. Vol. 20. 2529-2525.
4. [4] Oliveira, F.A.e., Franco, J.A., Fernandes, J.e. and Dias, D. 2002. Newly developed cordierite-zircon composites. British Ceramic Transactions. Vol. 1001. No.1.14-21.
5. [5] Cai, S., Yuan, Q., Meng, J., Yang, Z and Chen, Y. 2001. Lowtemperature ageing of zirconia-toughned mullite composites. Vo1.21. 2911-2915.
6. [6] Park, S., Saruhan, Band Scheneider, H. 2000. Mullite/zirconia laminate composites for high temperature application .. Vo1.20. 2463-2468.
7. [7] Zhao, S., Huang, Y., Wang, e., Huang, X. and Guo, J. 2003. Mullite formation from reaction sintering of ZrSi04/a-Ah03 mixtures. Vol. 57.1716-1722.
8. [8] Ebadzadeh, T. and Ghasemi, E. 2000. Influence of starting materials on the reaction sintering of mullite-ZrO, composites. A283. 289-297 .

9. [9] Haldar., M.K., Banerjee, G., 2003. Properties of zirconiamullite composites prepared from beach sand sillimanite. Materials Letters, 57,3513-3520.