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

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

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.

Özet

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.