20.500.12556/DKUM-58173 Reactive sintering of $MnZn$ ferrites Reaktivno sintranje $MnZn$ feritov Reaction-formed $MnZn$ ferrite was prepared and the decrease in shrinkage after sintering due to the volume expansion accompanying iron oxidation was studied. Green compacts consisting of the milled raw oxides $Fe_2O_3$, $Mn_3O_4$, $ZnO$ and metallic iron powder were sintered at 1350 °C in air. During the first hold at 800 °C, $Fe$ was oxidized to $\alpha-Fe_2O_3$ and $Zn$ ferrite was formed. Above 1300 °C the reaction bonding was completed and $MnZn$ ferrite, exhibiting a relatively low shrinkage, was formed. The chemical reactions involved during reaction bonding were associated with a volume expansion and porosity formation, compensating for the shrinkage on sintering. Intensive milling decreases the porosity after sintering but induces the oxidation of iron, and partially removes the shrinkage compensation caused by the presence of metallic iron. V delu poročamo o izdelavi reakcijsko vezane $MnZn$ feritne keramike z manjšim krčenjem med sintranjem zaradi povečanja volumna, ki spremlja oksidacijo kovinskega železa. Mlete mešanice praškov $Fe_2O_3$, $Mn_3O_4$ in $ZnO$ ter kovinskega železa smo stisnili v surovce in jih sintrali pri 1350 °C na zraku. Med segrevanjem se najprej oksidira železo, nastali $\alpha-Fe_2O_3$ pa reagira z $ZnO$ ob tvorbi $Zn$ ferita. Ti dve reakciji potečeta do 800 °C, v temperaturnem območju 900 °C – 1300 °C pa nastaja $MnZn$ ferit. Povečanje volumna, ki spremlja te reakcije, in razvoj poroznosti med reakcijskim sintranjem delno ali v celoti kompenzirata krčenje materiala med zgoščevanjem. Intenzivno mletje izhodnega materiala nekoliko ublaži zmanjšanje skrčka in sicer zaradi delne oksidacije kovinskega železa med mletjem in manjše poroznosti sintrane keramike. reaction-forming $MnZn$ ferrite inorganic technology ferrite ceramics reaction bonded ceramics sintering iron oxides iron anorganska tehnologija feritna keramika reakcijsko vezane keramike sintranje $MnZn$ feriti železovi oksidi železo true false true Angleški jezik Slovenski jezik Znanstveno delo 2016-04-08 17:42:39 2017-08-25 08:49:51 2022-06-16 03:07:11 2019-07-11 10:30:45 2001 0 0 str. 101-114 št. 1 Letn. 48 2001 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 1318-0207 66.046.44:666.593 14086149 23500037 1318-0207 URN:SI:UM:DK:ZCYW9T54 Acta_Chimica_Slovenica_2001_Kosmac,_Drofenik_Reactive_sintering_of_MnZn_ferrites.pdf Acta_Chimica_Slovenica_2001_Kosmac,_Drofenik_Reactive_sintering_of_MnZn_ferrites.pdf 1 C60A0520179D69DE7F057999A3479F06 a42eae6e2e8b4317d6aa1e44f95d2ba16ed4f29078345f91ffeded50e50318c2 8f5d17a4-7c0e-11eb-bb7a-00155d0001ca https://dk.um.si/Dokument.php?lang=slv&id=116013 http://acta-arhiv.chem-soc.si/48/48-1-101.pdf 1 https://dk.um.si/Dokument.php?lang=slv&id=88255 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0