LZSA glass ceramic foams prepared by replication process

Beitrag in einer Fachzeitschrift


Details zur Publikation

Autor(en): Fey T
Zeitschrift: Advances in Applied Ceramics
Verlag: Maney Publishing
Jahr der Veröffentlichung: 2005
Band: 104
Seitenbereich: 22-29
ISSN: 1743-6753


Abstract


In this study the replication process was applied to produce porous glass ceramic foams. Polyurethane (PU) sponges were impregnated by immersion in aqueous slurry of a parent glass (mean particle size around 3 pm) from the system Li2O-ZrO2-SiO2-Al2O3 and submitted to heat treatment. From TGA and IR analyses, two main paths of thermal decomposition of PU sponges were observed at 312 and 393degreesC, which were associated with the decomposition products CO2, CO, NH3 and isocyanide. According to linear thermal shrinkage and DTA measurements, sintering starts at around 570degreesC and is completed below 700degreesC, when crystallisation takes place. The main crystalline phases identified by XRD analysis were zirconium silicate, lithium metasilicate and beta-spodumene. The morphology and properties of the glass ceramic foams obtained from PU sponges were quite similar for all samples tested. From XCT measurements, a mean cell diameter of around 260 mum and mean strut thickness of 185 pm were calculated, corresponding to a porosity of 75-78%. Compressive strength values under 500 kPa and permeability coefficient in air of about 1000 Darcy were also measured for the samples tested. LZSA glass ceramic foams can be a very interesting alternative to ceramic gas filters, owing to low temperature processing, and to superior properties such as corrosion and thermal shock resistance.



FAU-Autoren / FAU-Herausgeber

Fey, Tobias Dr.
Lehrstuhl für Werkstoffwissenschaften (Glas und Keramik)

Zuletzt aktualisiert 2018-10-08 um 02:43