抄録
The microstructure and high temperature mechanical properties of biomorphic SiC ceramics have been investigated. The microstructure of biomorphic SiC causes a optimization in strength with respect to reaction bonded and reaction formed SiC. These materials show a continuous decrease in the creep rate for temperatures under 1600 oC, where the SiC does not deform plastically. This behavior is explained by a model of creep controlled by a viscous intergranular phase. The highest strengths were exhibited when compressed in the axial direction. The microstructure-strength correlation for a large variety of microstructures can be explained by the minimum solid area approach. In particular, this model clarifies: the origin of the differences in strength between the siliconized SiC materials; the dependence of strength with porosity; the anisotropy of the strength on biomorphic SiC; and the microstructural changes in biomimetic structures that self-oriented to reach the maximum strength at a given density.
