关键词: 莫来石, ZTM, 柱状晶粒, 断裂

Abstract: Mullite/mullite (rodlike) and ZTM/mullite (rodlike) ceramics with the microstructure of whisker toughening ceramics were fabricated. The research and analysis demonstrated that
rodlike mullite particles had relatively high fracture strength; The growth of rodlike particles changed the fracture mode from the mainly transgranular to the mixture type of transgranular
and intergranular in monophase mullite ceramics. A lot of rodlike particles pull-out from the matrix were observed in the fracture surface of the specimens. For ZTM, compressive stresses
in the matrix would be produced by the phase transformation of ZrO₂. So the bonding forces among the rodlike particles and matrix were enhanced and the debonding of rodlike particles
became difficult. The pull-out of rodlike particles from matrix became less in the fracture surfaces and this phenomenon was even more obvious for the specimen with high m-ZrO₂
content.

Key words: mullite, ZTM, rodlike, particles, fracture