Growth Mechanism of cBN by Metal Films

By using Ca3B2N4 as catalyst and treating hBN-Ca3B2N4 under high pressure and high temperature, we obtained cBN crystals covered with metal films at the junction of hBN and catalyst layer. This shows that the formation mechanism of cBN is similar to that of diamond. In this way, nuclei of cBN formed first at the contact face between hBN and catalyst wherein existed, the metal films between the cBN and solvent. The cBN cells move through the films and precipitate on the nuclei of cBN. As the films move toward the solvent, the cBN crystals become larger and larger. The films play an important role in the transfer of cBN cells.