Novel Porous Ceramic with High Strength and Thermal Performance Using Ma Hollow Spheres

Abstract

A novel facile strategy to fabricate porous ceramics by foaming and pore-forming agent methods using magnesia-aluminum spinel hollow spheres (MASHSs) was reported for the first time, in which calcium aluminate cement (CAC) served as high-temperature binder. The influence of temperature ranging from 1500 °C to1700 °C on the thermal conductivity, porosity and mechanical strength were investigated. The results show that, the obtained MASHSs ceramic exhibits high porosity (67.2~71.9%) and thermal conductivity (0.18~0.38 W/mK), and compressive strength (6.1~17.1 MPa), which is mainly due to the change in crack directions and microstructure optimization with the prolong of firing temperature. The crack directions changed from the surface of MASHSs to the interior MASHSs, which consumes more crack energy, and thus leading to the excellent mechanical performance. What’s more, the introduction of MASHSs makes it difficult to lose heat at elevated temperature, and thereby improving the thermal conductivity of materials.

Keywords: MA hollow spheres, porous ceramics, thermal conductivity, mechanical property