resumo
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).
palavras-chave
HYDROLYSIS-ASSISTED SOLIDIFICATION; FRACTURE-TOUGHNESS; DENSIFICATION BEHAVIOR; STARCH CONSOLIDATION; CERAMICS; ALUMINA; BODIES; RHEOLOGY; SPINEL; ROUTE
categoria
Materials Science
autores
Olhero, SM; Ganesh, I; Torres, PMC; Alves, FJ; Ferreira, JMF
nossos autores
agradecimentos
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.