Phase Equilibria in the System ZrO2─InO1.5

Phase equilibria in the system ZrO 2 ─InO 1.5 have been investigated in the temperature range from 800° to 1700°C Up to 4 mol%, InO 1.5 is soluble in t ‐ZrO 2 at 1500°C. The martensitic transformation temperature m → t of ZrO 2 containing InO 1.5 is compared with that of ZrO 2 solid solutions with various other trivalent ions with different ionic radii. The diffusionless c → t ′ A phase transformation is discussed. Extended solid solubility from 12.4 ± 0.8 to 56.5 ± 3 mol% InO 1.5 is found at 1700°C in the cubic ZrO 2 phase. The eutectoid composition and temperature for the decomposition of c ‐ZrO 2 solid solution into t ‐ZrO 2 +InO 1.5 solid solutions were determined. A maximum of about 1 mol% ZrO 2 is soluble in bcc InO 1.5 phase. Metastable supersaturation of ZrO 2 in bcc InO 1.5 and conditions for phase separation are discussed.