Spark plasma sintering of nano-crystalline ceramics
2004 (English)In: EURO CERAMICS VIII, PTS 1-3 / [ed] Mandal, H; Ovecoglu, L, Trans Tech Publications Inc., 2004, Vol. 264-268, 2297-2300 p.Conference paper (Refereed)
Spark Plasma Sintering (SPS) has been successfully applied in the sintering of nanocrystalline BaTiO3 and gamma-Al2O3 in order to reach fully dense nanostructured ceramics at moderate pressure and temperature. BaTiO3 compacts with densities exceeding 97% and gain size of 50 nm have thus been prepared at temperatures not exceeding 850degreesC using a uniaxial pressure of 100MPa. The selection of sintering temperature is critical for the purpose of minimizing grain growth and there is a demarcation temperature (820degreesC) between normal and abnormal grain growth for the nanocrystalline BaTiO3 powder used in this study. Fully dense alpha-Al2O3 compacts containing grains of the size 300nm or less were consolidated from high-purity gamma-Al2O3 powders without the use of additives or seeds. The transition temperature of gamma-Al2O3 to alpha-Al2O3 can be lowered to 960degreesC when gamma-Al2O3 powder is compacted in the SPS apparatus. The possible mechanisms related to this low transition temperature and to the sintering of both BaTiO3 and gamma-Al2O3 are discussed with special reference to the effect of the pulsed electric field generated by the pulsed electrical current used to heat the sample.
Place, publisher, year, edition, pages
Trans Tech Publications Inc., 2004. Vol. 264-268, 2297-2300 p.
, Key engineering materials, ISSN 1013-9826
sintering, nanocrystalline, BaTiO3, gamma-alumina
IdentifiersURN: urn:nbn:se:kth:diva-89038ISI: 000223059700550OAI: oai:DiVA.org:kth-89038DiVA: diva2:502624
8th Conference of the European-Ceramic-Society. Istanbul, TURKEY. JUN 29-JUL 03, 2003
QC 201203022012-02-142012-02-142012-03-02Bibliographically approved