Effect of the addition of alkaline earth sulfates to mullite ceramics on the corrosion and wetting by Al–Mg alloy. Issue 7 (July 2015)

• Record Type: Journal Article
• Authors: Ibarra, M.N.; Almanza, J.M.; Cortés, D.A.; Escobedo, J.C.; Pech, M.; Martinez, R.
• Is Part Of: Journal of the European Ceramic Society. Volume 35:Issue 7(2015:Jul.)
• Page Start: 2189
• Page End: 2194
• Publication Date: 2015-07
• Subjects: Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2015.01.025
• Languages: English
• ISSNs: 0955-2219

Abstract

<abstract abstract-type="author" id="abs0005"> <title id="sect0005">Abstract</title> <sec> <p id="spar0005">Novel ceramics showing a high corrosion resistance were obtained by adding alkaline earth sulfates to mullite (Al₆Si₂O₁₃). Powder samples of mullite, mullite–SrSO₄ and mullite–BaSO₄ were prepared. Disk pellets of 4 cm in diameter were conformed by uniaxial pressing at 78 MPa and sintered at 1450 °C for 6 h. Wetting experiments were carried out by the sessile drop test at 900 °C using an Al–7Mg alloy. After sintering, substrates of mullite, mullite–SrAl₂Si₂O₈ or mullite–BaAl₂Si₂O₈ were obtained. The contact angles between samples surface of alkaline earth sulfates containing mullite and molten alloy were higher than that corresponding to pure mullite, showing a non-wetting behavior. Cross-section analysis by SEM and EDS of samples after the wetting test showed that the corrosion products were spinel (MgAl₂O₄) and periclase (MgO). The BaAl₂Si₂O₈-containing samples showed a higher corrosion resistance.</p> </sec> </abstract>