Effect of Fe2O3 Addition and Sintering Temperature on mechanical Properties and Translucence of Zirconia Dental Ceramics with Different Y2O3 Content
Manuel Fellipe Rodrigues Pais Alves, S. Ribeiro, Paulo Atsushi Suzuki, Kurt Strecker, Claudinei dos Santos
Abstract
The influence of Fe 2 O 3 additions on the microstructure, mechanical properties and translucence of zirconia with 3 mol-% or 5 mol-% Y 2 O 3 was evaluated. Samples were pressed with different thickness and sintered at 1475, 1500, 1550 and 1600C for 2 h. Density, phases, microstructure, roughness, strength and translucency were analyzed. All samples showed densification greater than 99%. After sintering at 1600 C, the phase analysis revealed only tetragonal ZrO 2 in samples with 3% Y 2 O 3 , while in samples with 5% Y 2 O 3 the cubic ZrO 2 phase was identified. Significant increase in the grain size was noted, when increasing the Y 2 O 3 content from 3% to 5% from 0.8 m to 2.3 m for sintered samples at 1600C. The strength was affected with Y 2 O 3 content and no relevant influence of the Fe 2 O 3 on density, microstructure or mechanical properties. Visible reflectance spectroscopy analyses, related to the CIELab scale, indicate variation in the contrast ratio as function of thickness of samples and coloring agent Fe 2 O 3 content.