18 KB68 KB14 KB199219991998Irmančnik-Belič, LidijaŠventner-Kosmos, Alenkaštevilka:3/4letnik:32str. 209-212ISSN:1318-0010COBISSID:19464453URN:URN:NBN:SI:doc-WGPJMWAGslInštitut za kovinske materiale in tehnologijeŽelezarna JeseniceŽelezarna RavneŽelezarna ŠtoreKovine zlitine tehnologijeceramicgostotakemijske lastnostikeramikakorundmikrostrukturaKorundna keramika za spajanje s kovino| Alumina ceramics for ceramic to metal seals|Metal-to-ceramic seals are widely used in high vacuum technology. Dense high alumina ceramics with average grain diameter from 15 to ?$20\mum$? and densities over ?$3.70g/cm^3$? are the most suitable for MoMn metallization. In the present work 98% ?$Al_2O_3$? ceramics with additives from the ?$CaO-SiO_2$? and ?$CaO-Mg-SiO_2$? systems were ivestigated. The influence of sintering conditions, additive composition and starting alumina powder on densification and microstructure development was studied. The most suitable microstructures with average grain diameters of 14 and ?$20\mum$? were achieved with a coarse grained starting alumina powder and additive composition of 35% CaO, 5% MgO, 60% ?$SiO_2$? or 40% CaO and 60% ?$SiO_2$?, with prolonged sinterating at 1700°CSpoji keramike s kovino se v vakuumski tehnologiji široko uporabljajo. Za spajanje po MoMn postopku je najbolj primerna gosta korundna keramika z gostoto nad ?$3.70g/cm^$? in povprečno zrnavostjo ?$15-20 \mum$?. Preiskovali smo 98% ?$Al_2O_3$? keramiko z dodatki iz sistemov ?$CaO-SiO_2 in CaO-MgO-SiO_2$?. Študirali smo vpliv pogojev sintranja, sestave dodatkov in izhodne zrnavosti glinice na zgoščevanje in razvoj mikrostrukture. Najprimernejše mikrostrukture s povprečno zrnavostjo 14 oziroma ?$29\mum$? smo dosegli z grobozrnato glinico. Sestava dodatka je bila 35% CaO, 5% MgO, 60% ?$SiO_2$? oziroma 40% CaO in 60% ?$SiO_2$? in s podaljšanim sintranjem pri 1700°CNadaljuje se kot: Materiali in tehnologijeTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije