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

0494817 - ÚFM 2019 RIV GB eng J - Journal Article
Bertolla, Luca - Chlup, Zdeněk - Tatarko, P. - Hanzel, P. - Ševeček, O. - Roupcová, Pavla - Dlouhý, Ivo
Preparation and characterization of novel environmentally friendly Al2O3/SiO2/CaO ceramic foams.
Ceramics International. Roč. 44, č. 15 (2018), s. 19063-19069. ISSN 0272-8842. E-ISSN 1873-3956
Grant - others:AV ČR(CZ) SAV-18-12
Program: Bilaterální spolupráce
Institutional support: RVO:68081723
Keywords : Porous ceramics * Silicates * Thermal diffusivity * Compressive strength
OECD category: Ceramics
Impact factor: 3.450, year: 2018

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 degrees C) in order to oxidize the residual metallic phases. The resulting foams exhibited open porosity, densities ranging from 0.50 to 0.65 g/cm(3) and wide pore size distribution (0.04-400 mu m). The compressive strength and thermal diffusivity of these foams ranged from 2.12 to 1.01 MPa and from 0.27 to 0.45 mm(2)s(-1), respectively, which indicate their suitability as thermal insulator materials.
Permanent Link: http://hdl.handle.net/11104/0288004