Three types of dicalcium silicate (Ca2SiO4–calcium zirconate (CaZrO3) composites were fabricated and their microstructures correlated with their mechanical properties. In the first type, Ca2SiO4 was added as a minor phase. The second type consisted of a 50 vol% Ca2SiO4‐50 vol% CaZrO3 mixture, while in the third type, CaZrO3 constituted the minor phase. Pure CaZrO3 was also studied as a control and found to have a toughness which depended on its grain size. In composites with Ca2SiO4 as the minor phase, a toughness increase was observed and found to be a function of matrix grain size. The composite with the second type of microstructure had the highest toughness of about 4.0 Mpa. m1/2, which was about double that of the monolithic CaZrO3. No evidence was found for transformation toughening by the orthorhombic (β) to monoclinic (γ) transformation in Ca2SiO4. The main toughening mechanisms identified were crack deflection and crack branching. Microstructural observations indicated the existence of weak grain boundaries in CaZrO3 agglomerates as well as weak interfaces between the two phases.
|Original language||English (US)|
|Number of pages||8|
|Journal||Journal of the American Ceramic Society|
|State||Published - Jan 1994|
ASJC Scopus subject areas
- Ceramics and Composites
- Materials Chemistry