Dodaci Al2O3 za krupnozrnate keramike za metalizaciju

The metal to ceramics seals are widely used as permanent seals in high vacuum technology. For these seals a coarse grain alumina ceramics is needed since a high temperature MoMn metallization is often applied because of several advantages, such as high mechanical strength, low dielectric losses at high frequencies and others. The coarse grain ceramics are produced by sintering alumina with different additives which have to promote densification and grain growth with the liquid phase during sintering. The CaO-SiO2 and CaO-MgO-SiO2 systems were used as additives in the present work. Different characteristics of the formed liquid phases have caused similar densification but different grain growth rates.Spojevi metal–keramika mnogo se upotrebljavaju kao trajni vakuumski spojevi. MoMn metalizacija se često upotrebljava radi velike čvrstoće, malih dielektričnih gubitaka i sl. Za tu metalizaciju nužne su krupnozrnate keramike koje se proizvode sinteriranjem Al2O3 s raznim dodacima koji pospješuju rast zrna u tekućoj fazi tijekom sinteriranja. U ovom radu opisuju se keramike s dodacima CaO–SiO2 i CaO–MgO–SiO2