Chemical reactions and thermodynamics of high temperature alumina metallization have been investigated. During the firing of MoMn paste, reactions start with oxidation of manganese. The formed Mn3O4 reacts with alumina and SiO2 at a temperature lower than 1200 °C. The formation of the metallizing layer is a consequence of lowering of the free energy of the system. It is caused by redox and dissolution reactions, the formation of the glass phase and crystallization process from the liquid phase. With available thermodynamical data and according to the atmospheric conditions, some reactions were predicted and confirmed by X-ray diffraction.Istraživane su kemijske reakcije i termodinamika visokotemperaturne metalizacije korunda. Tijekom paljenja smjese MoMn, reakcije počnu oksidacijom mangana. Nastali Mn3O4 reagira s korundom i SiO2 na temperaturi ispod 1200 ◦C. Nastajanje metalnog sloja je posljedica smanjenja slobodne energije sustava. Smanjenje je posljedica redoks reakcije, odvajanja faza, nastajanja staklene faze i kristalizacije iz tekuće faze. Neke su reakcije predvidene i potvrđene rendgenskom difrakcijom
