Influence of alloy catalysts with different adhesion at carbon on the synthesis of carbonado polycrystalline diamonds

The influence of molybdenum, titanium, tantalum, boron, and carbon on the wetting of pyrographite in solutions based on Nichrome (20% Cr–80% Ni alloy) is studied. The surface tension of the melts is measured, as well as the limiting wetting angles for the melts at pyrographite. The work of adhesion of the melts at pyrographite is calculated. The Nichrome-based alloys are used as catalysts in the synthesis of polycrystalline carbonado diamonds. The synthesis of carbonado, in contrast to the synthesis of diamond single crystals and powder, proceeds deep in the region of thermodynamic stability of carbon. Therefore, the adhesive characteristics of the alloys have no significant influence on the formation of polycrystals. © 2015, Allerton Press, Inc.