Effect of sintering atmosphere on the property of ceria doped tetragonal zirconia polycrystals (Ce-TZP)

摘要

Ceria stabilized zirconia polycrystals (Ce-TZP) were prepared by varying concentration of ceria (10 and 12 mol %) by precipitation technique. The thermal analysis of the both powder show that crystallization starts at 450°C, however the total weight loss varies due to the variation of physically bonded water. The calcined powder (up to 950°C) did not show any difference in phases between 10 and 12 mol% Ce-TZP. The agglomerate size distribution of the both powder (850°C) shows monomodal distributions with D50=19.83µm (10 mol% Ce-TZP) and D50=5.84µm (12 mol% Ce-TZP) respectively. The non isothermal densification behavior shows the shrinkage starts at ~ 900°C for the Ce-TZP compacts. The relative density increases with increase in sintering temperature for air as well as nitrogen atmosphere. The t- ZrO2 phase retention decreases with increasing in sintering temperature i.e. 100 vol% and 87 vol% t-ZrO2 at 1400°C and 1600°C respectively for 12Ce-TZP respectively. Samples sintered in N2 atmosphere shows lower relative density as well as lower fraction of tetragonal phase as compared to air sintered at all the temperatures studied. Flexural strength, compressive strength, fracture toughness and hardness were measured. A maximum fracture toughness 13 MPa.m -1/2 was observed for 12 mol % Ce-TZP sintered in air atmosphere at 1600°C.