Computer Simulation of Physical and Mechanical Processes Running in the Reaction Cells of High-Pressure Installations in the Course of Synthesis of Diamonds

Abstract

We study the problem of finite-element simulation of coupled nonlinear nonstationary processes of electric conductivity, heat conduction, and thermoplasticity taking into account the phase transitions in the materials. As a practical application, we develop a procedure of computer simulation of the process of spontaneous crystallization of diamonds. We solve the problem of determination of the fields of temperature, stresses, and concentrations of phases in the reaction volume of a high-pressure installation and in the local diamond–melt–graphite system in the course of crystallization of diamonds. It is discovered that these fields are strongly coupled, the solutions obtained for the reaction mixture and local system are characterized by a pronounced mutual influence, and the effect of self-regulation of pressure in the reaction zone exists and takes the form of oscillations of pressure about the line of the graphite–diamond phase transition.