CLUSTER MECHANISM OF FORMATION OF MICROPOLYCRYSTALLINE DIAMOND AGGREGATES

Abstract

The structure of micropolycrystalline aggregates of the carbonado and ballas types determines their strength properties. The authors of focused attention on the porous structure of natural and synthetic micropolycrystalline diamond aggregates. In some cases, pores can be filled with different phases (syngenetic and/or epigenetic). In other cases, they are empty. The strength characteristics of diamond aggregates can be influenced by a comparatively low dislocation density of diamond crystallites and the second phase (inclusions of crystal-forming medium), which is more elastic than diamond and can play the role of absorber of dynamic loads. This puts forward the problem of investigating the mechanism of formation of micropolycrystalline aggregates based on the example of the graphite + metal-catalyst model system depending on the thermodynamic parameters and physicochemical state of the medium.