Production parameters affecting the synthesis and properties of hBN-SiC composites

Abstract

In this study, the hexagonal boron nitride (hBN)-SiC composite powder synthesis was investigated with an in situ reaction method. Boric acid (H3BO3) and urea (CO(NH2)(2)) were used for hBN formation. In the hBN-SiC composite powder synthesis, primarily raw materials were homogeneously stirred in ethanol with Si3N4 balls. The samples were calcined and sintered by spark plasma sintering at 2000 degrees C under pressure of 50 MPa for 15 min. The characterization of composite samples was carried out by XRD, SEM-EDS, FTIR, and TG-DTA. The bulk density, Vickers hardness, and Young's modulus of samples were also measured. Composites were obtained, which had homogeneous microstructure. Residual boron oxides were found in samples with short calcination times. Moreover, it was found that the production parameters affect the physical properties of the composites and the amount of the hBN in sintered samples.