Kumar, P and Nath, M and Ghosh, A and Tripathi, Himansu Sekhar (2016) Thermo-mechanical properties of mullite-zirconia composites derived from reaction sintering of zircon and sillimanite beach sand: Effect of CaO. Transactions of Nonferrous Metals Society of China, 26 (9). pp. 2397-2403. ISSN 1003-6326

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Abstract

Mullite-zirconia composites containing 20% zirconia (mass fraction) were prepared by reaction sintering route utilizing Indian coastal zircon flour and sillimanite beach sand. 4%-12% of CaO (mole fraction) with respect to zirconia was used as additive. The effect of additive on densification, microstructure as well as various mechanical and thermo-mechanical properties was studied. Incorporation of CaO reduced the densification temperature of the composites to 1550 degrees C compared to 1600 degrees C (for CaO free samples). CaO formed small amount of liquid phase (calcium aluminosilicate), which facilitated sintering. Average grain size of the composites decreased up to 4% CaO addition, afterwards grain size increased with further addition of CaO. Samples with 4% CaO exhibited similar to 225 MPa of flexural strength, similar to 6 MPa.m(1/2) of fracture toughness and significant improvement in thermal shock resistance. CaO stabilized the tetragonal zirconia phase and thus improved the mechanical properties.

Item Type:	Article
Subjects:	Refractories
Divisions:	Refractory
Depositing User:	Bidhan Chaudhuri
Date Deposited:	31 Jan 2017 06:29
Last Modified:	15 Feb 2017 07:18
URI:	http://cgcri.csircentral.net/id/eprint/3806

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