The effects of mechanical activation on the sintering of mullite produced from kaolin and aluminum powder. Issue 10 (1st August 2016)

• Record Type: Journal Article
• Authors: Sahraoui, T.; Belhouchet, H.; Heraiz, M.; Brihi, N.; Guermat, A.
• Is Part Of: Ceramics international. Volume 42:Issue 10(2016)
• Page Start: 12185
• Page End: 12193
• Publication Date: 2016-08-01
• Subjects: Kaolin (DD3) -- Mechanical activation -- Aluminum oxidation -- Reaction-sintering -- Mullite; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2016.04.157
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: In this work, the effects of mechanical activation on the sintering of mullite produced from kaolin and aluminum metal powder was investigated. Because of the higher content of silica in kaolin it is necessary to add alumina or aluminum oxide in order to obtain the stoichiometric mullite composition. After mechanical treatment for different milling time, the reactions and phase transformations between kaolin and aluminum metal powder were studied using thermal techniques (DTA/TG), X-ray diffraction (XRD) and infrared spectroscopy (FT-IR). The heated samples at different temperatures were studied by XRD, apparent density, open porosity measurements and SEM analysis. The results showed the formation of silicon, quartz and small amount of nacrite after 40 h of milling at room temperature. All mixture powders milled for different time showed the formation of several alumina transitions during heat treatment. The formation of alumina transitions, α-alumina, cristobalite crystallization of and mullite (primary and secondary) formation was affected by ball milling time. The mixture of kaolin and aluminum milled for 40 h show the formation of kyanite (Al2 SiO5 ) at 1300 °C. The mechanical treatment enhances the formation and sintering of mullite.