Aging behavior of a 1.5 mol% yttria doped zirconia exhibiting optimized toughness and strength

The aging behavior of a 1.5Y-TZP with 0.25 wt% of alumina exhibiting high mechanical properties was investigated in both water vapor and in air with in situ XRD analysis. The results showed that the material exhibited a high resistance to aging in water vapor at 134 degrees C compared to 3Y-TZP, which is explained by the addition of alumina and a lower sintering temperature. The aging kinetics were fitted by the Mehl-Avrami-Johnson law, three stages were identified corresponding to predominance of nucleation mechanism for temperatures below 180 degrees C and above 340 degrees C and to growth mechanism for intermediate temperatures. It was shown that for the temperature range investigated in water vapor and air, the mechanism was independent on the environment. A strong influence of the cooling rate on the tetragonal to monoclinic phase transformation was observed and discussed using a time-temperature-transformation diagram derived from the aging results in air.

Automated summary

The aging behavior of a 1.5Y-TZP with 0.25 wt% of alumina was investigated, with results showing high resistance to aging in water vapor and the influence of cooling rate on phase transformation.