A novel strategy for low-temperature fabrication of porous CA6 ceramics using reactive CaCl2-KCl medium and its influence mechanism

Abstract

This paper proposes a novel strategy to fabricate porous calcium hex-aluminate (CA6) ceramics using CaCl2-KCl as reactive medium. Effects of CaCl2-KCl content and sintering temperature on microstructure and properties of porous CA6 ceramics are systematically studied. CaCl2-KCl serves as both a pore former and an additional source of CaO, eliminating the need for additional salt-washing treatment. By optimizing CaCl2-KCl content to 20wt%, porous CA6 ceramics with well cross-interlocking plate-like structures, possessing low thermal conductivity of 0.32W·(m·K)-1 (1000°C), high apparent porosity of 68.28%, and desirable compressive strength of 6.76MPa, are fabricated at 1300°C. This work not only validates the promising applicability of porous CA6 materials for thermal insulation, but also introduces an auspicious fabrication methodology for thermal insulation materials.