The use of the plasma electrolyte process has never been considered as a simple, cheap and fast method of obtaining powders used in selective laser melting processes. Therefore, the adaptation of the ...plasma-electrolyte process to the production of metal powders used in additive production is an urgent task. The paper presents the results of studies of gas discharge parameters between a metal and liquid electrode in the processes of obtaining metallic iron powders. The discharge combustion conditions necessary for the formation of metal powders of micron size are determined. A possible mechanism for the formation of powder particles in a discharge plasma is proposed.
Abstract
The article presents a solution to the problem of predicting the anode oxygen yield. The numerical algorithm developed by the authors makes possible to determine the rates of constants in ...electrode processes in accordance with the given experimental yield data, as well as to calculate the concentrations of substances involved in electrode processes at a specific point in time. The implementation of the method is shown as the calculation of the oxygen yield during the electrolysis of a potassium oxide aqueous solution, and it is based on the experimental data. The results of numerical studies are in good agreement with the experimental data.
Plasma technologies have a wide range of applications: from agriculture and the food industry to energy industry. Such widespread use is due to the properties of plasma and a wide variety of methods ...for its preparation. Also, in metallurgy, plasma is used as a source of thermal energy, capable of producing metal melting in a short time. The paper studies the process of obtaining a metal powder from a CoCr alloy in a gas discharge with liquid electrodes. The regularities describing the relationship between discharge parameters and properties of the powders obtained. The resulting powders can be used in Selective Laser Melting technology.
Selective laser melting technologies are widely used in various industries and medicine. A gradual increase in the volume of manufactured products requires the creation of new cheap methods for ...producing metal powders. One of the new methods for producing powders is the plasma-electrolyte method. A feature of this method is the use of gas with liquid electrodes, which allows you to get a metal powder and quickly cool it in a liquid. The question of the influence of discharge parameters on the process of metal atomization remains open. The paper studies gas discharges with liquid electrodes under the conditions of atomization of a metal anode. A gas discharge between a liquid electrolyte and a metal electrode was studied experimentally in the voltage range 300 - 1000 V. Solutions of sodium chloride in distilled water were used as the electrolyte. The conditions are established under which a stable discharge column is formed and metal powder is sprayed. The regularities of the change in the CVC of the discharge depending on the interelectrode distance are determined. A splitting of the spectral lines of the yellow sodium doublet was found in the emission spectrum of a gas discharge.
In modern conditions, hydrogen energy is of particular importance in the transition to alternative energy sources. One of the most common methods for producing hydrogen is electrolysis. In this ...paper, we propose a method for the numerical optimization of problems of chemical kinetics. This numerical algorithm makes it possible to find the rates of constants in near-electrode processes in accordance with the given experimental data on the yield and calculate the concentrations of substances involved in near-electrode processes at specific points in time. The numerical simulation of near-electrode processes of a functioning electrolytic cell is carried out. A comparative analysis of the calculation of the yield of hydrogen and oxygen in the process of electrolysis of a potassium hydroxide solution at a constant temperature with the values obtained in the course of a full-scale experiment is given. The results of numerical studies are in close agreement with the experimental data.
The work is aimed at studying the changes of the heat balance in the system of the electrode-plasma-gas vapor-electrolyte in various forms of applied voltage. It was established that in contrast to ...the voltage, which is obtained after full-wave rectification, film boiling occurs by using a smoothing capacitive filter. This is because in the pulsing mode voltage value has zero value at the beginning and end of the pulse, also at that time takes place cooling of the electrode at the contact with the electrolyte. In this paper describes a heat exchange in two different modes of plasma-electrolytic treatment.
Abstract
Titanium powders are widely used in selective laser melting and electron beam melting technologies to create medical implants. However, powders of a certain fractional composition are ...suitable for these purposes. A gradual increase in the volume of manufactured products requires the creation of new cheap methods for obtaining metal powders. Plasma-chemical synthesis in titanium tetrachloride solution can be one of the new methods for producing powders. A feature of this method is the use of a gas discharge with liquid electrodes, as a liquid electrode and is a titanium tetrachloride solution. The aim of the work was to study the possibility of obtaining a metal powder and its rapid cooling in a liquid. The question of the influence of the discharge parameters on the formation of metal particles remains open. In this work, a study of a gas discharge with liquid electrodes under the conditions of anode and cathode modes is carried out. A gas discharge between a liquid electrolyte and a metal electrode is experimentally investigated in the voltage range of 300-1000V. The conditions under which a stable discharge column is formed and a metal powder is formed are established. The regularities of the change in the I–V characteristic of the discharge are determined depending on the interelectrode distance.
Abstract
In this work, a new process of plasma-electrolyte sputtering under the action of ultrasonic vibration is proposed, which makes it possible to obtain a finely dispersed metal powder with an ...average particle diameter of about 100 μm. The process involves irradiation with a high-power continuous laser on a consumable metal substrate vibrating at an ultrasonic frequency. The burning of a gas discharge around the vibrating electrode causes the surface to melt and small droplets are ejected. Preliminary results of spraying stainless steel 12X18H9T with a discharge power of 800 W and an ultrasonic vibration frequency of 20 kHz are presented. Vibration displacement does not significantly affect average particle size and size distribution according to capillary wave spray theory. The microstructure of the larger atomized particles exhibits a fine dendritic structure on the surface and shrinkage porosity at the center of the particles, indicating multiple surface nucleation for solidification.
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