abstract
This paper reports on the synthesis of magnesium aluminate spinel (MAS) powders and consolidation of MAS ceramics by hydrolysis-induced aqueous gelcasting (GCHAS). The MAS powders surface passivated against hydrolysis were dispersed in an aqueous-organic premix solution using suitable dispersants. The consolidation of green bodies occurred under ambient conditions by adding a polymerization initiator, a catalyst, and AlN (0-4.06 wt%) as a cosetting agent. Green samples with exceptionally high green strength (similar to 21 MPa) were obtained in the presence of 4.06 wt% AlN. Sintered (1650 degrees C, 1 h) MAS ceramics consolidated by GCHAS exhibited mechanical properties that are comparable to those consolidated by dry pressing.
keywords
MGAL2O4 SPINEL; ASSISTED SOLIDIFICATION; DENSIFICATION BEHAVIOR; CERAMICS; POWDERS; ROUTE
subject category
Materials Science
authors
Ganesh, I; Reddy, GJ; Sundararajan, G; Olhero, SM; Torres, PMC; Ferreira, JMF
our authors
José Maria da Fonte Ferreira
Retired Professor
Paula Maria da Costa Torres
Assistant Researcher
Susana Maria Henriques Olhero
Assistant Professoracknowledgements
I. G. thanks SERC-DST (Government of India) for the awarded BOYSCAST fellowship (SR/BY/E-04/06). S. M. O. thanks the Foundation for Science and Technology (FCT) of Portugal for the financial support under the grant SFRH/BPD/27013/2006. The financial support of CICECO is also acknowledged.