INFLUENCE OF CHEMICALLY ACTIVE CARBON ELEMENTS FOR THERMAL RESISTANCE OF DIAMOND CONTAINERS COMPOSITION MATERIALS

Abstract

The paper presents the results of theoretical and experimental studies of the heat resistance of diamond-containing composite materials, including diamonds with coatings that is the influence of temperature on the physical and mechanical properties of the composite. It is shown that these properties depend on the interaction of diamonds with chemically active with respect to carbon components of the composite. It is known that diamond is a metastable phase of carbon, and metals that are chemically active with respect to carbon are catalysts for the process of graphitization of diamond on an interfacial surface. The analysis of literature data and data obtained by the authors on the effect of temperature on the phase transformation of diamond into graphite is carried out. It is shown that in an inert medium to carbon, diamond is preserved as a phase up to the melting point of diamond in the metastability region indicated in the p,T-phase diagram of carbon. An analysis of graphitization of diamonds on the interfacial surface in contact with metals and oxygen at various temperatures was carried out. The effect of the thickness of the coatings on the thermal stability of diamonds during heat treatment in a gaseous medium chemically active to carbon was experimentally established. The results of research and development of heat-resistant coatings on diamonds with high adhesion and not forming graphite on the interfacial surface are presented