Summary of the slow crack growth SCG

3. Results and discussions
The microstructures are shown in Fig. 1. The LP-Fine consists of homogenous fine equiaxed grains with average grain size of 1.0 ± 0.1 μm. LP-Coarse has elongated grains with a length of 16 ± 1 μm and a width of 5 ± 0.3 μm. This has been achieved using β-SiC powder, which is known to lead to elongated grains due to the enhanced β → α BW 723C86 at temperatures above 1850 °C [18], [35], [36], [37] and [38]. For the SS-Fine, the grains have an average size of 4.0 ± 0.4 μm and are therefore larger than the LP-Fine grains, this is due to the boron addition which enhances grain growth [39]. The grains in the SS-Coarse have a length of 18 ± 1 μm and a width of 5 ± 0.3 μm.
Fig. 1. Scanning electron micrographs of chemically etched silicon carbide materials of this work.Figure optionsDownload full-size imageDownload as PowerPoint slide