One of the main directions of engineering technology development at present is the improvement of existing and the development of new waste-free, environmentally friendly, material-saving production processes. Powder metallurgy is a branch of technology, including the manufacture of powders from metals and their alloys and the preparation of blanks and products from them without melting the main component. In most cases, new materials are created in order to provide the optimal combination of product price and operational characteristics. Chromium is the most common alloying element. Steel alloyed with chromium has increased strength, hardness, wear resistance, resistance to corrosion in aggressive and oxidizing environments. The presence of chromium increases the hardenability of steel. The process of obtaining powder materials by the method of electroerosive dispersion compares favorably with the possibility of producing powders even from particularly hard and refractory materials. In the case of grinding material by this method, the only important criterion is the electrical conductivity of the material being ground. Worn parts and other scrap can be used as feedstock during the process. The purpose of the study is to investigate the powder obtained from the waste of chromium-containing steels. Thanks to the study of the used powder samples on modern devices, results were obtained, which indicate that the chromium-containing powder, obtained by electroerosive dispersion, can be reused in the restoration and hardening of machine parts.

One of the main requirements for powders for additive 3D technologies is the spherical shape of particles. Such particles are most densely fit into a certain space and provide the ‘fluidity’ of powder compositions in the systems of material supply with minimal resistance. In addition, the powder should contain a minimum amount of dissolved gas. The microstructure of the powder should be homogeneous and finely dispersed (with a uniform distribution of phase constituents). Based on the peculiarities of the methods of producing spherical powders in order to obtain spherical granules of regulated granularity, the electroerosion dispersion (EED) technology, which is characterized by relatively low energy costs and environmentally sound process, is proposed. The main advantage of the proposed technology is the use of waste materials as raw stuff which are much cheaper than the pure constituents used in traditional technology. In addition, this technology allows varying the granulometric composition of the resulting powder by changing electrical parameters. The objective of this work is to study the porosity of sintered samples of cobalt-chromium powders obtained for additive technologies by means of electroerosion dispersion. To implement the proposed research, wastes of the cobalt-chromium alloy of KHMS "CELLIT" grade were chosen. Distilled water and isobutyl alcohol were used as the working fluid. Electrical discharge machine to disperse conductive materials was used to produce cobalt-chromium powders. The powders are consolidated by the method of spark plasma sintering using the spark plasma sintering system SPS 25-10 (Thermal Technology, USA). The initial material was put in a graphite matrix placed under a press in a vacuum chamber. Electrodes integrated into the mechanical part of the press feed electric current to the matrix and create spark discharges between the sintered particles of the material, providing intensive interaction. The porosity was determined using Olympus GX51 optical inverted microscope with a software for quantitative image analysis. Prepared samples had no traces of structural components grinding, polishing or dying. The microsection metalographic specimen was made by the cross section (fracture) of the whole product. Based on the results of the conducted experiment aimed at studying the porosity of sintered samples from cobalt-chromium powders obtained for additive technologies by electroerosion dispersion in isobutyl alcohol, it was found that the porosity ranges from 3.19 to 6.15 %.

The article presents the results of a study of the elemental composition of sintered products from alloy X17 electroerosive materials obtained in lighting kerosene. It is shown that the main elements on the surface of sintered products are chromium, iron and nickel.

Purpose of reseach was to evaluate the dimensional characteristics of powders obtained by electrodispersion of high-chromium corrosion-resistant steel in lighting kerosene.Methods. When setting up experiments for electroerosive dispersion, wastes of high-chromium corrosion-resistant steel X17 were selected. Dispersing equipment - experimental setup (RF Patent No. 2449859). Lighting kerosene was used as a working fluid. In order to stabilize the process, the dispersion modes were selected experimentally and were as follows: voltage 100 V; pulse repetition rate 120 Hz; capacity 48 μF. The granulometric composition of the powders was studied using a laser particle size analyzer "Analysette 22 NanoTec".Results. It has been found that the average particle size is 28.66 pm and 95% of the total volume of particles in the powder have a size less than or equal to 57.36 pm. ,based on the conducted experimental studies aimed at studying the particle size distribution of electroerosive powders obtained from wastes of high-chromium corrosion-resistant steel X17 in lighting kerosene on an experimental setup (RF Patent No. 2449859) at a pulse repetition rate of 120 Hz, a voltage of 100 V and the capacity of the discharge capacitors is 48 μF.Conclusion. The conducted research will allow us to obtain new powder materials from wastes of high-chromium corrosion-resistant steel X17 in lighting kerosene with a guaranteed particle size distribution, through the use of progressive, environmentally friendly, low-tonnage and waste-free technology of electroerosive dispersion.

The article presents the results of porosity study of sintered products from electro-erosive materials of alloy Cr17, obtained in lighting kerosene. It was shown that during the consolidation of electro-erosion materials from Cr 17 alloy by the method of spark plasma sintering, the porosity was 0.27%.