Characterization of SiC/C (B)/SiC microcomposites by transmission electron microscopy |
| |
Authors: | S Jacques A Guette F Langlais X Bourrat |
| |
Affiliation: | (1) Laboratoire des Composites Thermostructuraux, Unite Mixte de Recherche, Universite CNRS-Societe-UB1 47, Bordeaux I, 3 allee de la Boetie, 33600 Pessac, France |
| |
Abstract: | Uniform or composition-graded C(B) (i.e., boron-containing carbon) interphases in SiC/SiC model microcomposites were characterized
by transmission electron microscopy after tensile tests and thermal ageing in air. A specific method was developed to prepare
thin longitudinal sections of the tested specimens. Deflection of matrix cracks occurs within the uniform C(B) interphase,
as long as its anisotropy remains high enough (i.e., when the boron content is not too high). It takes place close to the
most anisotropic layer (i.e. that containing 8 at% of boron) in composition-graded interphases. In both cases, the crack deflection
path does not reach the fibre, a feature which is consistent with the good mechanical properties. After ageing in air under
tensile loading beyond the proportional limit (600°C; σ=800 MPa), the composition-graded interphase (made of five sublayers
in which the boron content increases from 0 at% near the fibre to 33 at% near the matrix) was observed to act as a glass-forming
protection, the pyrocarbon sublayer (at the fibre surface) remaining unoxidized.
This revised version was published online in November 2006 with corrections to the Cover Date. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|