abstract
Two different zirconia-alumina composites, ZTA-30 (70 wt% Al(2)O(3)+30 wt% ZrO(2)) and ZTA-60 (40 wt% Al(2)O(3)+60 wt% ZrO(2)), with potential for orthopedic applications, were processed in aqueous media and consolidated by slip casting (SC), hydrolysis-assisted solidification (HAS), and gelcasting (GC) from suspensions containing 50 vol% solids loading. For comparison purposes, the same ceramic compositions were also consolidated by die pressing of freeze-dried granules (FG). In the HAS process, 5 wt% of Al(2)O(3) in the precursor mixture was replaced by equivalent amounts of AlN to promote the consolidation of the suspensions. Ceramics consolidated via GC exhibited higher green (three-point bend) strengths (similar to 17 MPa) than those consolidated by other techniques. Further, these ceramics also exhibited superior fracture toughness and flexural strength properties after sintering for 1 h at 1600 degrees C in comparison with those consolidated by other techniques, including conventional die pressing (FG).
keywords
HYDROLYSIS-ASSISTED SOLIDIFICATION; FRACTURE-TOUGHNESS; DENSIFICATION BEHAVIOR; STARCH CONSOLIDATION; CERAMICS; ALUMINA; BODIES; RHEOLOGY; SPINEL; ROUTE
subject category
Materials Science
authors
Olhero, SM; Ganesh, I; Torres, PMC; Alves, FJ; Ferreira, JMF
our authors
José Maria da Fonte Ferreira
Retired Professor
Paula Maria da Costa Torres
Assistant Researcher
Susana Maria Henriques Olhero
Assistant Professoracknowledgements
Financial support was provided under the grant SFRH/BPD/27013/2006 by Foundation for Science and Technology of Portugal. The financial support of CICECO is also acknowledged.