SELF REINFORCED BARIUM TITANATE CERAMICS BY BARIUM TITANATEFIBRES

摘要

Self reinforced barium titanate ceramics were achieved following a novel routine, namely,by sintering nanosized BaTiO_3 particles reinforced with 5-wt.% BaTiO_3 fibres, without extraaddition of second phase as reinforcing agen. A hydrothermal technique and a cellulose-methodwere used to synthesize BaTiO_3 nano-particles and fibres, respectively. The crystalline phase inthe powders and fibres was determined as cubic and tetragonal BaTiO_3, respectively. Greenbodies were shaped from BaTiO_3 particle/BaTiO_3 fibre mixtures by slip casting (SC).Rheological measurements indicated that the addition of the fibres facilitate the aqueousprocessing of the nanopowders. Furthermore, the fracture toughness of sintered body(1200°C/2h) was 2.22 Mpa·m~(1/2), higher than that of the SC non-reinforced matrix (1.92Mpa·m~(1/2)). The microstructures and electrical properties of the sintered bodies wereinvestigated. It was found that the reinforced ceramics exhibited improved toughness withoutsignificant degrading the dielectric properties.