Preparation and characterization of novel environmentally friendly Al2O3/SiO2/CaO ceramic foams

článek v časopise ve Web of Science, Jimp

en

Low–cost Al2O3-SiO2-CaO ceramic foams were prepared using a novel and simple reactive foaming process. The foamed green bodies were produced by mixing aluminium powder and calcium hydroxide in an aqueous solution of sodium silicate and sintered in an argon atmosphere using a pressureless electric current assisted process (T = 800 °C). An additional thermal treatment was performed in air using a conventional furnace (T = 1050 °C) in order to oxidize the residual metallic phases. The resulting foams exhibited open porosity, densities ranging from 0.50 to 0.65 g/cm3 and wide pore size distribution (0.04–400 µm). The compressive strength and thermal diffusivity of these foams ranged from 2.12 to 1.01 MPa and from 0.27 to 0.45 mm2s−1, respectively, which indicate their suitability as thermal insulator materials.

Low–cost Al2O3-SiO2-CaO ceramic foams were prepared using a novel and simple reactive foaming process. The foamed green bodies were produced by mixing aluminium powder and calcium hydroxide in an aqueous solution of sodium silicate and sintered in an argon atmosphere using a pressureless electric current assisted process (T = 800 °C). An additional thermal treatment was performed in air using a conventional furnace (T = 1050 °C) in order to oxidize the residual metallic phases. The resulting foams exhibited open porosity, densities ranging from 0.50 to 0.65 g/cm3 and wide pore size distribution (0.04–400 µm). The compressive strength and thermal diffusivity of these foams ranged from 2.12 to 1.01 MPa and from 0.27 to 0.45 mm2s−1, respectively, which indicate their suitability as thermal insulator materials.

Porous ceramics; Silicates; Thermal diffusivity; Compressive strength

15.10.2018

Elsevier

Netherlands

0272-8842

44

1

19063–19069

7