ZrB₂grains synthesized on graphite by chemical vapor deposition

ZrB₂grains were prepared on graphite by chemical vapor deposition using a gas mixture of ZrCl₄, BCl₃, H₂and Ar at 1150 °C. The microstructure and phase composition of the coating were investigated by SEM, XRD, XPS and TEM. The results indicated that ZrB₂grains were deposited and grown directly by a vapor–solid growth mechanism on graphite without intermediate phase. Granulated ZrB₂grains were composed by many sub–grains with different crystal orientation. The rod–like or pagoda–like ZrB₂grains with lamellar structures were grew on the granulated ZrB₂particles and composed of two parts: the internal part with axial stacking faults and annular part with radial stacking faults.