Reaction thickness between diamond and silicon under 5 GPa

The thickness of the silicon carbide layer around diamond grains in the reaction sintering process of diamond/SiC composites starting from diamond and silicon was investigated at 1100–1400 °C and 5 GPa using two different sample assemblies. Dense silicon carbide layers with thicknesses from 60 nm to 350 nm were observed using energy dispersive spectrometry (EDS) and X-ray diffraction (XRD) analysis. This demonstrated that the thickness of the silicon carbide layer increased with increasing sintering temperature and time. The surface morphology of diamond grains/single-crystal diamond wafers eroded by liquid silicon was analysed by field emission scanning electron microscopy (FESEM), and it was found that SiC growth was controlled by the diffusion of silicon and carbon atoms through the existing layer of SiC. [Display omitted] •The thickness of silicon carbide layer around diamond grains was measured at 1100–1400 °C and 5 GPa. Dense silicon carbide layers with thicknesses from 60 nm to 350 nm were observed using EDS and XRD analysis.•The thickness of silicon carbide layer increased with the increase of temperature and SiC growth was controlled by the diffusion of silicon and carbon atoms through the existing layer of SiC.•The quantitative data of the thickness of silicon carbide layer around diamond under high pressure is reported for the first time.