resumo
In this study, the influence of La-rich glass addition and sintering conditions on the densification and mechanical properties of 3 mol.% Y2O3 tetragonal zirconia polycrystals (3Y-TZP) ceramics were evaluated. High-purity tetragonal ZrO2 powder stabilized with 3 mol.% Y2O3 and La2O3-Rich glass were used as starting powders. Two compositions, ZrO2 containing 5 and 10 wt.% of a La2O3-rich glass were studied in this work. The starting powders were mixed/milled by planetary milling, dried at 90 degrees C for 24 hours; sieved through a 60 mesh screen and uniaxially cold pressed under 80 MPa. The samples were sintered in air at 1200, 1300 and 1400 C for 60min, and at 1450 degrees C for 120min, with heating and cooling rates of 10 degrees C/min. Sintered samples were characterized by relative density. X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The mechanical properties. hardness and fracture toughness. were obtained by Vickers indentation method. Dense sintered samples were obtained for all conditions. Samples sintered at 1300 C for 60 min presented the optimal mechanical properties with hardness of 1170 kgf.mm(-2) and fracture toughness of 8.3 MPam(1/2).
palavras-chave
MECHANICAL-PROPERTIES; DENTAL COMPOSITES; TETRAGONAL ZIRCONIA; FRACTURE-TOUGHNESS; RESIDUAL-STRESS; MICROSTRUCTURE; STRENGTH; STABILITY
categoria
Engineering; Materials Science
autores
Santos, C; Souza, RC; Fernandes, MH; Almeida, N; Almeida, FA; Silva, RF
nossos autores
Flávia Aparecida de Almeida
Bolseiro de pós-Doutoramento
Maria Helena Figueira Vaz Fernandes
Professor(a) Jubilado(a)
Rui Ramos Ferreira e Silva
Professor associadoGrupos
G3 - Materiais Eletroquímicos, Interfaces e Revestimentos
G5 - Materiais Biomiméticos, Biológicos e Vivos
agradecimentos
The authors acknowledge the FAPESP for financial support under Grants no. 04/04386-1; and 05/52971-3.