A study of the crystal structure of a commercial β-SiC whisker by high-resolution TEM

The crystal structure and defects in a commercial TWS-100 β-SiC whisker were observed and analyzed by means of high-resolution transmission electron microscopy. It was found that the SiC whiskers with triangular or hexagonal cross-sections both have a face-centered cubic structure, while their crystal defects are different. The defects in the triangular whisker are mainly stacking faults on the (1 1 1) planes which are not perpendicular to the whisker axis, however, in the hexagonal whisker there are a great amount of micro-twins and stacking faults on the (1 1 1) planes perpendicular to the whisker axis. The high-density defects account for the hexagonal close-packed (HCP) diffraction patter obtained in the HCP β-SiC whiskers, which is first pointed out by analyzing the crystal structure of the β-SiC whisker.