Microstructural Development in Calcium Hexaluminate with and without Fe2O3 Doping at Different Forming Method

Manidip Jana1, Swapan Kumar Das2

1 Refractory Division, CSIR-Central Glass & Ceramic Research Institute, Kolkata 700 032/India
2 Refractory Division, CSIR-Central Glass & Ceramic Research Institute, Kolkata 700 032, India

Revision

Volume 6, Issue 4, Pages 61 - 65

Abstract

Calcium hexaluminate (CA6) was synthesized from a mixture of anhydrous Ca(OH)2 and Al(OH)3 with or without Fe2O3 doping at a predetermined temperature of 1550 °C. Two different forming methods (uniaxial and isostatic pressing) were adopted to fabricate samples. Uniaxially pressed sample without Fe2O3 results higher porosity (17,14 %) with the formation of hexagonal platelet CA6 grains while isostatic pressed sample with lower porosity (8,22 %) resulted more equiaxed CA6 grains. Low concentration of Fe2O3 (5 %) did not formed CAF2, which is the only stable phase in CaO–Al2O3–Fe2O3 system. However it was observed that 5 % Fe2O3 addition enhances the grain growth which is beneficial for refractory application.

Keywords

calcium hexaluminate, forming methods, additives, microstructure

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