Influence of electrode arrangement method on specific energy consumption and productivity in electrosynthesis of fine graphite powder

Andrei V Kupriashov,Ivan Y Shestakov

doi:10.1007/s00170-021-08500-6

Abstract

In this work, the influence of the location of the electrodes on the productivity of electrochemical process and specific energy consumption during direct current electrosynthesis of finely dispersed graphite powder is considered. The authors consider the possibility of using finely dispersed graphite powder obtained by electrolysis as the main component of a multifunctional aerospace coating. For this purpose, two types of devices were constructed: with a coaxial and parallel arrangement of the electrodes. The main elements of the device are a stainless steel cathode and a graphite anode immersed in electrolyte (an aqueous solution of salts). The authors consider the influence of the arrangement of the electrodes in the installation for direct current electrosynthesis from the point of view of the energy efficiency and productivity of electrochemical process. As a result of anodic oxidation, a fine powder from graphite of the MPG-6 brand was obtained. The size of the resulting graphite particles is 1–50 µm. This finely dispersed graphite powder can be used as the main component of a multifunctional coating in aircraft, since it has an even homogeneous structure, as well as higher values of the main mechanical properties of a multifunctional coating, which will lead to a decrease in the number of layers and the thickness of the coating applied. The resulting graphite powder can also be used in the production of fire-retardant and heat-insulating materials for the chemical, nuclear industry, instrumentation, and heat power engineering.

Highlights

A multifunctional coating is a multilayer structure applied on the surface of a product to protect it from external influence [13].During operation, aircraft, in addition to force influences, are continuously exposed to an extensive complex of external physical influences of a heterogeneous type: ionizing and radio emissions, large differences in thermal disturbances, harmful effects of electrodynamic and gravitational fields, geomagnetic and ionospheric factors [4,5,6,7]
When using a multifunctional coating as a filler, the graphite powder obtained by electrolysis from MPG-6 brand graphite with a particle size range of 0.004÷0.05 mm, in comparison with mechanically crushed graphite powder, provides the following advantages: 1. Higher values of the main multifunctional coating mechanical properties, due to the high particle density of the main component; 2
The value of specific energy consumption directly depends on the current density – the higher the anode current density, the lower the values of specific energy consumption of the electrochemical process; 3

Summary

Introduction

A multifunctional coating is a multilayer structure applied on the surface of a product to protect it from external influence (pressure, temperature, corrosion, erosion, vibration) [13].During operation, aircraft, in addition to force influences, are continuously exposed to an extensive complex of external physical influences of a heterogeneous type: ionizing and radio emissions, large differences in thermal disturbances, harmful effects of electrodynamic and gravitational fields, geomagnetic and ionospheric factors [4,5,6,7]. The creation of an external multifunctional coating for the protection of rocket and space objects, which has a huge range of possibilities for reflection and absorption from external negative factors, is an urgent task in modern aerospace engineering. In Aerospace Engineering, the main purpose of multifunctional coatings is thermal protection, protection against ionizing, electromagnetic and radio emission, reflection of laser influence, aimed at influencing the control system, electrical equipment and product devices. The secondary functions of multifunctional coating in rocket technology include increasing the strength and stiffness of individual external parts of the product, as well as protection against corrosion and erosion [8, 9]. The role of the shape and size of fillers for distribution and sedimentation in the polymer composite is very important for obtaining coatings with specified quality and functional characteristics [10,11,12]. The uniform distribution of filler particles in the polymer composite is determined by their tendency to agglomeration and sedimentation

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Conclusion