resumo
Dense zirconia-toughened alumina (ZTA) ceramic composites with ZrO(2) = 0, 5, 10, 15, 20, 30, 60 and 100 wt.% have been prepared by sintering green compacts obtained by dry powder pressing of freeze dried granules consisting of alpha-alumina and a yttria partially stabilized zirconia (YPSZ) at various temperatures ranging from 1450 to 1650 degrees C for 1-2 h. The characteristics of sintered products were determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), Archimedes principle, Vickers indentation method and by 3-point bend test. Characterization results revealed that adding YPSZ increased the 3-point bend (flexural) strength, fracture toughness and homogeneity of the microstructure, but slightly decreased the hardness and the sintering ability of alumina. A 20 wt.% YPSZ was sufficient to increase the fracture toughness and flexural strength of specimens sintered for 2 h at 1600 degrees C from 2.5 to 4.6 MPa m(1/2) and 150 to 400 MPa, respectively. The XRD results revealed that there is no solid-solution formation between zirconia and alumina constituents of ZTA ceramic composites upon sintering. (C) 2010 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
palavras-chave
FRACTURE-TOUGHNESS; DENSIFICATION BEHAVIOR; MECHANICAL-PROPERTIES; ALUMINA; SPINEL; INTERFACE; ABUTMENT
categoria
Materials Science
autores
Ganesh, I; Sundararajan, G; Olhero, SM; Ferreira, JMF
nossos autores
José Maria da Fonte Ferreira
Professor(a) Jubilado(a)
Susana Maria Henriques Olhero
Professor Auxiliaragradecimentos
IG thanks SERC-DST (Government of India) for the awarded BOYSCAST fellowship (SR/BY/E-04/06). The financial support of CICECO is also acknowledged.