Distributed reaction surface of carbon-graphite volume-porous cathodes as a parameter for optimizing of metallization process of composite and nanocomposite materials

Introduction. The porous composite and nanocomposite materials discussed in this publication are metallized carbon-graphite materials, in particular carbon fiber materials (CFMs). At metallization of CFMs one of the actual problems is the task of applying uniform metal coating on the surface of CFMs fibers over the entire volume of the processed material. One of the most effective ways to coat CFMs with metals and their alloys is the galvanic method. This method allows, among other things, to optimize the process by optimizing both the design of the electrolyzer with flow-through three-dimensional electrodes (FTE) and the choice of electrodeposition modes, such as galvanic, concentration, and hydrodynamic. Materials and methods. Methods of mathematical modeling of porous medium metallization processes and previously published experimental data were used to solve problems on calculation of operating modes and elements of the electrolyzer design, in particular, the specific reaction surface of the UWM distributed over the thickness of the electrolyzer. Results and discussion. The development of mathematical models of the processes of electroplating metallization of CFMs is carried out. Boundary value problems of mathematical physics are formulated and calculation methods are proposed. Problems of optimization of distribution of specific reaction surface of CFMs by thickness of FTE on the basis of electrochemical theory of processes in porous medium are set, ways of their solution are presented. Specific technological problems are solved. The comparison of the most effective values of the distribution of specific reaction surface of CFMs over the thickness of FTE obtained as a result of modeling with the experimental data is given. The workability of models and methods for studying the process of copper electrodeposition from sulfuric acid electrolyte is shown. Conclusion. Calculation of regularities of electrochemical processes of metal extraction in FTE on the basis of the developed mathematical models allows to predict the results of electrolysis, determine the optimal modes of operation and elements of FTE design. The use of FTE for metallization of CFMs with properly distributed reaction surface contributes to obtaining composite materials with specified properties.