Effect of Yttria in Sintering Behaviour of Alumina

Abstract

Densification of alumina has been studied in the present work in presence of yttria. Yttria as dopant has been added to the extent of 0.5, 1 and 2 weight % to pure alumina and studied for pressure-less sintering. Pellets of without and with yttria containing compositions were sintered at 15500C 16000C, 16500C and then characterized for densification, phase analysis and SEM & EDAX studies. A new phase, Y3Al5O12, has been observed in the sintered samples indicating reactions between alumina and dopant phase. Results reveal that yttria is a beneficial sintering additive for alumina on sintering at 16500C, at lower temperatures it has a hindering effect on sintering. Microstructural study indicates the improvement and EDAX study confirm the presence of yttrium and aluminium containing oxide phases, observed as brighter grains.