Proprietà di porcellane elettriche ottenute con materie prime ugandesi: Studio degli effetti dovuti alla formaulazione dell'impasto e alla temperatura di sinterizzaione
2008 (English)In: Ceramurgia, ISSN 0045-6152, Vol. 38, no 1, 17-25 p.Article in journal (Refereed) Published
Five sample mixtures of Ugandan kaolin, ball clay, feldspar and flint were formulated and porcelain samples fabricated by extrusion through a vacuum pugmill. Samples were evaluated for formability. The degree of densificaron of sintered specimens fired at 1200 to 1350°C was evaluated by measuring the firing shrinkage, bulk density, water absorption and bending strength. Crystalline phases and mullite morphology were studied using XRD and SEM respectively. Dielectric strength measurements were carried out on disc specimens. Dielectric and bending strength properties deteriorated at high temperatures because of pore formation and decreasing amount of undissolved quartz in the crystalline phase. An optimum composition of 30% kaolin, 15% ball clay, 30% feldspar and 25% quartz yielded an unglazed body with highest bending strength of 72MPa and dielectric strength of 19MVm-1 after firing at 1250°C. The body consisted of small, closely packed mullite needles and undissolved quartz crystals embedded in a glass matrix.
Place, publisher, year, edition, pages
2008. Vol. 38, no 1, 17-25 p.
Absorption, Bending (deformation), Clay, Clay minerals, Crystalline materials, Feldspar, Kaolin, Optical design, Oxide minerals, Quartz, Silicate minerals, Strength of materials, Water absorption, X ray diffraction analysis, (p, p, t) measurements, Ball clay, Bulk density (BD), Crystalline phase, Crystalline phases, Dielectric strengths, Disc specimens, Firing shrinkage, High temperature (HT), Optimum composition, Pore formations, Sintered specimens, Strength (IGC: D5/D6), strength properties, Bending strength
Mineral and Mine Engineering
IdentifiersURN: urn:nbn:se:kth:diva-154467ScopusID: 2-s2.0-46849091609OAI: oai:DiVA.org:kth-154467DiVA: diva2:757634
QC 201410232014-10-232014-10-202015-10-12Bibliographically approved