Synthesis and thermo-mechanical properties of mullite-alumina composite derived from sillimanite beach sand: effect of ZrO2

Citation
Hs. Tripathi et al., Synthesis and thermo-mechanical properties of mullite-alumina composite derived from sillimanite beach sand: effect of ZrO2, CERAM INT, 27(8), 2001, pp. 833-837
Citations number
18
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
CERAMICS INTERNATIONAL
ISSN journal
0272-8842 → ACNP
Volume
27
Issue
8
Year of publication
2001
Pages
833 - 837
Database
ISI
SICI code
0272-8842(2001)27:8<833:SATPOM>2.0.ZU;2-Z
Abstract
A mullite-alumina composite was developed by reaction sintering of silliman ite beach sand and calcined alumina. ZrO2 (2-6 wt.%) was added as additive. The raw materials and additive were mixed, attrition milled and sintered i n compacted form at 1400-1600 degreesC with 2 h soaking. The effect of ZrO2 on the densification behaviour, thermo-mechanical properties and microstru cture was studied. It was found that addition of ZrO2 slightly retards the densification process. All the samples achieved their highest bulk density at 1600 degreesC. Thermo-mechanical properties of the sintered samples are not effectively altered by the presence Of ZrO2. ZrO2 containing samples al ways show better resistance to thermal shock than the ZrO2 free samples. Sc anning electron micrography shows that ZrO2 occupies both an intergranular and intragranular position in the mullite matrix. The mullite formed at 160 0 degreesC is mostly equiaxed in nature that suggests densification mainly occurs through solid state sintering. (C) 2001 Elsevier Science Ltd and Tec hna S.r.l. All rights reserved.