Abstract
In order to improve the thermo-mechanical performances of SiC/SiC composite, process improvement
and modification by the combination of nano-infiltration and transient eutectic-phase (NITE) method
and chemical vapor infiltration (CVI) method were studied. Multilayered PyC/SiC fiber coating and matrix
infiltration within fiber-tows were prepared with isothermal/isobaric CVI (ICVI) method and full-densification
of SiC matrix was examined with NITE methods using four kinds of processing options. Applied
pressure was useful for nearly-full matrix densification due to the promoting infiltration driving force of
SiC nano-powder intra-fiber-tows, but simultaneously caused the sever degradation of fibers and interphase
with fracture, resulting in lower strength. Increase of additives amount and additional polymer
were effective ways for matrix densification by SiC nano-power infiltration intra-fiber bundles without
pressure. Thermal conductivity was greatly improved with the decrease of matrix porosity. The tailoring
of thermo-mechanical properties might be easily controlled by the SiC matrix porosity without processinduced
fibers and interphases degradations.
