Silicon nitride/silicon carbide(w) ceramic matrix composites synthesized from common starting materials, except for the whiskers themselves, under the same processing conditions have been investigated. High-resolution electron microscopy and high-spatial-resolution electron energy loss nanospectroscopy were used to characterize the whisker/matrix interfaces in these composites both structurally and chemically. The presence of a discontinuous oxygen-rich amorphous layer at the two kinds of whisker/matrix interfaces examined in this paper appeared to be a general phenomenon. The wide difference (a factor of 10) between the structural image and chemical widths (oxygen distributions) of the whisker/matrix interfaces was attributed to oxygen solution into the silicon nitride matrix. The oxygen sources were the sintering aids and surface impurities.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics