Low temperature sintering of mechanically activated BaCO3-TiO2

In this article low temperature sintering of mechanically activated BaCO3-TiO2 system was studied. A stoichiometric mixture of BaCO3 and TiO2 powders was mechanically activated in a high-energy vibromill for 0, 30, 90 and 180 min, calcined at 800oC for 1 h and reaction sintered at 1100oC and 1200oC for 2 h (heating rate of 10oC/min). Phase compositions and crystallographic data of initial, activated, calcinated and sintered specimens were obtained by the XRPD method. It was noticed that mechanical activation enhanced and lowered the temperature of the formation of tetragonal BaTiO3. Scanning electron microscopy was used to study and characterize microstructures of the samples.U ovome radu je proučavano niskotemperaturno sinterovanje mehanički aktiviranog sistema BaCO3-TiO2. Prah BaCO3 i TiO2 u stehiometrijskom odnosu je mehanički aktiviran u visokoenergetskom vibracionom mlinu tokom 0, 30, 90 i 180 min, kalcinisan na 800oC tokom jednog časa i reakciono sinterovan na 1100 i 1200oC tokom dva časa (brzina zagrevanja je iznosila 10oC/min). Fazni sastav i kristalografski podaci početnih i aktiviranih smesa, kao i kalcinisanih i sinterovanih uzoraka dobijeni su rendgenskom metodom. Skanirajućom elektronskom mikroskopijom proučena je mikrostruktura uzoraka. Utvrđeno je da mehanička aktivacija ubrzava proces sinterovanja, uz snižavanje temperature formiranja tetragonalnog barijum-titanata