14 KB1466 KB14 KB200020242000Kolar, DragoKramberger, AlbinaZupan, Klementinaštevilka:1/2letnik:344 stranistr. 57-60ISSN:1580-2949COBISSID:214186URN:URN:NBN:SI:doc-08DR35FEslInštitut za kovinske materiale in tehnologijeMateriali in tehnologijelantanov kromitsintezazgorevanjeVpliv pakiranja zgorevalne zmesi na potek sinteze pri citratno nitratnem postopku| Influence of the citrate-nitrate reaction mixture packing on combustion synthesis|A citrate-nitrate gel combustion reaction was used for the submicron crystalline strontium substituted lanthanum cromite (LSC) preparation. The influence of the reaction mixture packing prior combustion for the different fuel contents on the reaction temperature and reaction period, phase formation and specific surface area of so prepared powders was investigated. It was shown that the reaction period depends on fuel/oxidant ratio and reaction mixture packing. The reaction duration time was few seconds for the loose packed layer prepared samples and few tens of seconds for samples prepared from the pallete, respectively. The nature of the agglomerates formation was studied by SEM in the green compacts pressed at 300 MPa. Thermal analysis was used to determine degree of conversion for as prepared samplesLastnosti prahov, ki nastanejo pri zgorevalni sintezi v sistemih gorivo/nitrat, niso odvisne le od redukcijsko-oksidacijskega razmerja, temveč tudi od geometrije reakcijske zmesi. Te vplive smo spremljali pri izgorevanju citratno-nitratnih gelov lantanovega kromita, dopiranega s stroncijem (LSC). Ugotovili smo, da geometrija zgorevalne mešanice določa čas pri temperaturi sinteze ter s tem specifično površino nastalih produktov, vrsto kristalnih faz in stopnjo pretvorbe. Sinteza v nasuti plasti poteče za stehiometrijske mešanice v nekaj sekundah, medtem ko so sinteze v tableti potekale nekaj deset sekund. Naravo aglomeratov v produktu smo spremljali z elektronsko mikroskopijo zelenih tablet, stisnjenih pri tlaku 300 MPa. S termično analizo smo ugotavljali zreagiranost produktov sintezeTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije