Abstract
As a part of the study on sintering, the effects of oxide additives on sintering of LaFeO3 compacts were investigated in air. The density, isothermal shrinkage and grain growth of sintered bodies were measured in relation to the sintering time, temperature and oxide additives. The lattice constants of the specimens were obtained by using the X-ray diffraction method.
The results are summarized as follows.
(1) The sintering of LaFeO3 was markedly promoted by the addition of TiO2 or MnO2 at the sintering temperature of 1450°C. The Cu2O addition caused a liquid phase sintering and promoted sintering.
(2) The grain boundary diffusion mechanism was recognized during the initial sintering in the temperature range of the present experiment.
(3) The grain size of LaFeO3 sintered bodies without any additives was shown to be smaller than those with 5mol% TiO2, ZnO, and MnO2 addition. The activation energy for grain growth obtained from the Arrhenius plot was found to be 150, 100, 93 and 103kcal/mol, respectively.
(4) The lattice constants of 20mol% CaO additive specimen showed 0.036% increase along a axis and 0.127% decrease along c axis compared with those of LaFeO3 specimen.
