Samanta, A K and Dhargupta, K K and Ghatak, Sankar (2001) Near net shape SiC-mullite composites from a powder precursor prepared through an intermediate Al-hydroxyhydrogel. Ceramics International, 27 (2). 195 -199. ISSN 0272-8842

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SiC-mullite composites with low dimensional changes on sintering were fabricated by partial oxidation of SiC followed by reaction bonding using hydroxyhydrogel derived alumina keeping SiC as dispersed phase in the intermediate gel-like mass as starting material. The sintering-induced shrinkage is compensated by Volume expansion caused by the silicon carbide oxidation-induced-volume expansion. This work describes a new processing route to fabricate SiC-mullite composites where in situ formation of mullite takes place that proceeds at much lower temperatures (less than or equal to 1600 degreesC) than in normal ceramics processing routes. Specimens containing Al2O3 less than or equal to 40% are not suitable due to the formation of large amount of low eutectic aluminosilicates at processing temperatures. Specimens containing greater than or equal to 40% Al2O3 yield different aluminosilicates, mainly mullite, which acted as a retarder for oxidation of SiC and at the same time it helped to consolidate SIC compacts. Final phases in fired compact were identified by XRD and different phases present were calculated on the basis of X-ray diffraction results.

Item Type: Article
Uncontrolled Keywords: Composites; Mullite; SiC; Near Net Shape; Hydroxyhydrogel
Subjects: Ceramic-Metal Systems
Divisions: Non-Oxide Ceramics & Composites
Depositing User: Mrs Chandana Patra
Date Deposited: 22 Mar 2012 12:57
Last Modified: 15 Feb 2017 07:35

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