| 摘要 |
Generally, this invention provides a toughened ceramic composite and a method of enhancing the mechanical strength of ceramic matrix composites through use of a transformation weakened interphase material. The ceramic composite provided in this invention includes a ceramic matrix, a second material as a second phase, and a metastable interphase material. The metastable interphase material is positioned between the ceramic matrix and the second phase material. The ceramic composite can include reinforcing elements such as fibers, whisker-shapes, platelets and particulates or have laminated or fibrous monolithic geometries. The metastable interphase material is capable of undergoing a shear or stress induced zero volume or negative volume, martensitic phase transformation, which may or may not be accompanied by a crystallographic unit cell shape change. In one embodiment, the metastable interphase material includes beta-cristobalite.
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