The Study of Particle Size Distribution of Electroerosion Chrome-Containing Powder, Used for Wear Resistant Surfacing

Abstract

Perpose of research. To study the particle size distribution of electroerosive chrome-containing powder, suitable for surfacing. Methods. To carry out the planned studies, chrome-containing steel wastes were selected. The carbon-containing working fluid was chosen as the working fluid, namely, lighting kerosene. To obtain chrome-containing powder materials by electroerosive dispersion the device for EED of conductive materials was used. The dispersible material was poured into a desiccator, filled with a working fluid, namely, lighting kerosene. The authors studied the particle size distribution of the obtained powders by the method of dispersion in a liquid with ultrasound. Research technique (FR 1.27.2009.06762 “Methodology for measuring particle size in suspensions, emulsions and aerosols in the nanometer and colloidal ranges using the effect of dynamic light scattering”) has been used. Results. It is experimentally established that the particle shape of the obtained powder material is due to the form in which the material is ejected from the hole during the EED process. It is also seen that particles having a regular spherical or elliptical shape prevail in the powder material. They are obtained by crystallization of the molten material (liquid phase). The particles formed during crystallization of the boiling material (vapor phase) have an irregular shape, an order of magnitude smaller than the particles formed by their liquid phase, and usually agglomerate with each other on the surface of other particles. In the EED process, such particles are most susceptible to chemical and phase changes. Conclusion. Studies of the particle size distribution of chrome-containing powder material obtained by electroerosive dispersion of waste in lighting kerosene under the following electrical parameters of the operation of the EED unit: capacity of discharge capacitors 45 μF, voltage at the electrodes 100 ... 110 V, pulse repetition rate of the generator 55 ... 65 Hz determine the average particle size of the powder material and the specific surface area. The results will allow us to determine the rational area of their practical application.