Local texture of three-stage CVD SiC fibre by precession electron diffraction (PED) and XRD

TL;DR

This study investigates the local texture of three-stage CVD SiC fibres using XRD and PED, revealing stage-dependent grain orientations and sizes that influence the fibre's mechanical properties.

Contribution

It provides detailed insights into the stage-wise texture evolution of CVD SiC fibres using combined XRD and PED analysis.

Findings

First stage has random grain orientation.

Second and third stages show specific textures: (110),111 and (110),115.

Grain size decreases at the third stage due to lower temperature.

Abstract

SiC fibre with the transverse isotropic properties is very important to it reinforced metal matrix composites. In this paper, local texture of the CVD SiC fibre was investigated by means of X-ray diffraction (XRD) and precession electron diffraction (PED) on transmission electron microscopy(TEM). The result from XRD is in agreement with the result obtained from PED. And the result shown that at the first stage of deposition, the preferred direction of SiC grains is almost random and the distribution of grain size is scattered. At the second and third stages of deposition, there are two kinds of texture in SiC fibre, that is, (110),111. and (110),115.. Furthermore, the grain size at the second and third stages is about 200 nm and it is lower at the third stage than at the second stage because of the lower temperature at the third stage. The [110] preferred direction along axial direction for SiC fibre is beneficial to the axial tensile strength.