Chatterjee, Minati and Naskar, Milan Kanti and Chakrabarty, P K and Ganguli, Dibyendu (2002) Mullite fibre mats by a sol-gel spinning technique. Journal of Sol-Gel Science and Technology, 25 (2). pp. 169-174. ISSN 0928-0707

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Abstract

Fine grained, microcrystalline mullite (Al4+2xSi2-2xO10-x) fibre mats with a web-like structure were fabricated by a sol-gel spinning technique using a multi-orifice spinneret. Points of contact in gel fibre mats helped in the formation of a web-like fibrous body having reasonable strength and very little dust formation after calcination. Strong and resilient fibres with diameters in the range 3-12 mum were obtained by a single-step sol-gel method from spinnable sols devoid of organics as the binder aid. Crystallization of gamma-alumina and mullite at about 900degreesC and 1250degreesC, respectively was confirmed by differential thermal analysis (DTA) and X-ray diffraction (XRD). Thermogravimetry (TG) indicated the removal of most of the volatiles at about 500degreesC accompanied by a weight loss of about 48%. Scanning electron microscopy (SEM) shows the presence of small grains (80-150 nm in size) in the fibres calcined at 1250degreesC. Fourier transformed infrared spectroscopy (FTIR) indicated the sequence of transformations taking place during heat-treatment of gel fibres at different temperatures. The individual fibres in the mats calcined at 1250degreesC exhibited a tensile strength of 1300-1600 MPa.

Item Type: Article
Uncontrolled Keywords: Sol-gel processes; Mullite fibres; Refractories
Subjects: Engineering Materials
Divisions: Sol Gel
Depositing User: Bidhan Chaudhuri
Date Deposited: 22 Mar 2012 12:32
Last Modified: 22 Mar 2012 12:32
URI: http://cgcri.csircentral.net/id/eprint/1340

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