Sinhamahapatra, Somnath and Ghosh, Chandrima and Tripathi, Himansu Sekhar and Mukhopadhyay, Sunanda (2021) Effect of Yb2O3 and TiO2 on reaction sintering and properties of magnesium aluminate spinel. Ceramics International, 47 (19). pp. 27372-27385. ISSN 0272-8842

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Abstract

Magnesium aluminate spinel with an initial MgO: Al2O3 molar ratio of 2:1 was prepared from its constituent oxides through a solid-state sintering process at temperatures ranging from 1550 to 1700 degrees C in a normal air atmosphere. The effect of varying amount (0.25-1.0 wt%) of TiO2 and Yb2O3 on densification, phase assemblage, mechanical, thermo-mechanical properties and microstructure of magnesia-rich spinel were investigated under static heating condition. The addition of TiO2 and Yb2O3 favours the densification of magnesia-rich spinel, which is discernible up to 1650 degrees C. This beneficial effect may be attributed to the development of the secondary phase and formation of solid solution due to the dissolution of the additive ions in the spinel structure. A marginal increase in the average grain size of the samples along with a narrower grain size distribution occurred with the incorporation of both the additives. Both the additives improved the mechanical properties of the magnesia-rich spinel; however, better room temperature flexural strength was achieved with Yb2O3 as compared to TiO2 addition. For the samples sintered at 1550 degrees C, 1.0 wt% Yb2O3 addition resulted in 30% increase in flexural strength; however, same amount of TiO2 addition increased the strength by 20%. In case of thermal shock resistance, 1.0 wt% TiO2 and 0.25 wt% Yb2O3 addition demonstrated promising result among all the samples.

Item Type:	Article
Subjects:	Refractories
Divisions:	Refractory
Depositing User:	Bidhan Chaudhuri
Date Deposited:	22 Dec 2021 10:07
Last Modified:	22 Dec 2021 10:07
URI:	http://cgcri.csircentral.net/id/eprint/5293

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