Quantitative linear correlations between the cBN synthesis parameters and the structural features of the hBN precursor

Seven selected hBN powders previously characterized by X-ray diffraction were subject to cBN synthesis tests at 1500 °C and 5.2GP using MgB2 as a solvent-catalyst. Attempts have been made to establish quantitative linear correlations involving the conversion yield and the kinetic parameters (nucleation rate and linear growth rate) obtained in the cBN synthesis and the X-ray revealed features of the hBN precursor to disclose definite hereditary influences in the hBN → cBN conversion. The aspect ratio of the hBN crystallites seems to have an influence on the conversion yield and nucleation rate only if considered jointly with the graphitizing index and special lattice defects such as nanoarches and mid-plane point defects of chemical origin. The model of Sung and Tai for the catalytic synthesis of diamond was used to explain the obtained correlations.