Frittage des céramiques à base de Kaolin et Dolomie

Abstract

Because of their excellent mechanical and electrical, cordierite (2MgO. 2AI2O3. 5SiO:) and anorthite (CaO. AI2O3. 2Si02) ceramics may be used in various mechanical thermal and electronic applications. These ceramics are usually elaborated by complicated and cost chemical methods ( Sol-Gel) or formed by controlled relatively temperatures melting ( 1500- 1 700°C). In this work, we have used as started materials both Kaolin and Doloma ( in range of 12% - 20 % wt. of doloma) to obtain a composite of cordierite and anorthite. An almost full density was obtained by heat treating a compacted precristallised powders. X-ray diffraction was used to identity the formed phases. The effect of temperature and content doloma on the number and nature of formed phases were studied. The most important results are : - Preparation from kaolin and doloma mixtures of material mainly composed of two important phases namely cordierite and anorthite. this preparation was conducted under easy processing. - Densification at 1265°C of composite, where density as high as 98% of theoretical was reached. - Cordierite and anorthite ceramics have a critical sintering approaches the melting point of this composite. Finally, it has also been found that both microhardness and microstructure of certain simples are closely related to the amount of doloma addition.