resumo
Different types of dense 5-97% ZrO2-MgAl2O4 Composites have been prepared using a MgAl2O4 spinet obtained by calcining a stoichiometric mixture of aluminium tri-hydroxide and caustic MgO at 1300 degrees C for 1 h, and a commercial yttria partially stabilized zirconia (YPSZ) powder as starting raw materials by sintering at various temperatures ranging from 1500 to 1650 degrees C for 2 h. The characteristics of the MgAl2O4 spinet, the YPSZ powder and the various sintered products were determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), BET surface area, particle size analysis, Archimedes principle, and Vickers indentation method. Characterization results revealed that the YPSZ addition increases the sintering ability, fracture toughness and hardness of MgAl2O4 spinet, whereas, the MgAl2O4 spinet hampered the sintering ability of YPSZ when sintered at elevated temperatures. A 20-wt.% YPSZ was found to be sufficient to increase the hardness and fracture toughness of MgAl2O4 spinet from 406 to 1314 Hv and 2.5 to 3.45 MPa m(1/2), respectively, when sintered at 1600 degrees C for 2 h. (c) 2007 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
palavras-chave
MAGNESIUM ALUMINATE SPINEL; MECHANICAL-PROPERTIES; REFRACTORIES; SINTERABILITY; BEHAVIOR
categoria
Materials Science
autores
Ganesh, I; Ferreira, JMF
nossos autores
José Maria da Fonte Ferreira
Professor(a) Jubilado(a)agradecimentos
IG thanks SERC-DST, Government of India, for awarding BOYSCAST Fellowship (SR/BY/E-04/06). The financial support of CICECO is also acknowledged.