[en] The phase transformations in zirconia take place between 900deg - 1000deg and 1200degC while heating, and between 1000deg and 800deg - 600deg C while cooling causing material movement. Hence, effect of amount of CaO and CaF₂ additions and calcination temperature on densification and stabilization was studied by thermal cycling between 1200deg and 700degC (lower range) and 1400deg and 700degC (higher range) up to 25 thermal cycles. It was observed that higher densification can be obtained by thermal cycling at lower temperature compared to the temperature required in normal sintering process, particularly so, with CaO additions. High density was attained with CaO additions up to 2 per cent compared to equivalent amount of CaF₂ additions in the lower temperature range. In general, uncalcined compositions attained high density which decreased with increasing calcination temperature. Thermal cycling promoted stabilization. The reaction was almost completed within 5 thermal cycles. (author)