Dense mullite-zirconia-zirconium titanate ceramic composites by reaction sintering

N.M. RENDTORFF; M. S. CONCONI; N.M. RENDTORFF; M. S. CONCONI; S. GOMEZ; G. SUAREZ; S. GOMEZ; G. SUAREZ; M.R. GAUNA; E.F. AGLIETTI; M.R. GAUNA; E.F. AGLIETTI

CERAMICS INTERNATIONAL

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2016 vol. 42 p. 1563 - 1572

0272-8842

Materials from the Al2O3?SiO2?ZrO2 and the Al2O3?SiO2?ZrO2?TiO2 systems have several high temperature applications because they present the good refractoriness, chemicalinertness, adequate mechanical and thermo-mechanical behavior swit harelatively good cost: performance ratio. In this works toichiometric(3:2:1) molar in compatible mixtures of alumina (Al2O3), zircon (ZrSiO4) and titania (TiO2) were slip casted and sinteredin a 1300?1500 1C temperature rangein order to obtain mullite (3Al2O32SiO2), zirconia (ZrO2) and zirconium titanate (ZrTiO4) dense triple ceramic composite.Both sinterin gandre action occurre dafter the thermaltreatments. Reaction progress and densification evolutions were established.Dense Triplex composite materials were achieved after 1500 1C treatments. There action sintering was followed by XRD,TG?DTA, and dilatometry.Densification started at 1100 1C and the chemical reactions only started above1300 1C. Aluminum titanate(Al2TiO5) was found to bean intermediate of there action after 1400 1C treatments. Materials treated below 1300 1C presented apartial densification of the unreacted starting powders. Resulting ceramic materials were characterized. The crystalline phases were evaluated, as well as the texture properties.The achieved microstructure consisted in inter locked multiphase ceramic with zirconia(monoclinic)grains.The achieved Hvand KIC reached 9GPaand 4.3 MPam1/2 respectively. The dense and inter locked ceramicmic rostructure and relative high mechanical properties of the developed materialencourages several high temperature applications. Finally it can be point edoutthat after 1500 1C treatments some detrimental grain growthwasobserved.