Electroerosive Powders Research Articles

Structure and properties of alloys based on electroerosive brass powder LS58-3 obtained in distilled water

The purpose of this work was to study the microstructure and physico-mechanical properties of alloy blanks based on electroerosive powder brass of the LS58-3 brand obtained in distilled water. Methods. To carry out the planned research, waste of the LS58-3 alloy was selected. Distilled water was used as the working fluid. In an experimental patented installation for producing powders, waste LS58-3 alloy was dispersed in distilled water with a load mass of 300 g. The following modes were used: capacitor capacity 45–65 μF; voltage at the electrodes from 150–200 V; pulse repetition rate 50–100 Hz. The preparation of new alloy blanks was carried out using an SPS 25-10 electric spark plasma sintering installation (ThermalTechnology, USA). The microstructure of new alloy workpieces was studied using an electron-ion scanning (raster) microscope QUANTA 600 FEG (Netherlands). The study of the porosity of workpieces of new alloys was carried out using an optical inverted microscope OLYMPUS GX51 (Japan). The study of microhardness of workpieces of new alloys was carried out using an automated microhardness tester AFFRI DM-8 (Vickers). Results. Analysis of the microstructure showed that the sample has a fine-grained structure and a homogeneous surface. According to the obtained porosity analysis results, the sample has less than 1% pores, which is achieved thanks to the technology of spark plasma sintering of the powder. Analysis of the microhardness of the sample showed a significant increase in microhardness, which is explained by the presence of high-hard particles formed during quenching of metal vapor in the working fluid during dispersion. Conclusion. The use of spark plasma sintering technology for electroerosive brass makes it possible to obtain blanks of new alloys with a practically non-porous structure, which leads to an increase in the hardness of the resulting blanks. The results of the conducted studies make it possible to recommend the use of the resulting powder as a starting material for the production of alloy blanks and to expand the scope of their practical application.

Properties of an SSu-3 Lead–Antimony Alloy Sintered from Electroerosion Powders Produced in Distilled Water

Properties of an SSu-3 Lead–Antimony Alloy Sintered from Electroerosion Powders Produced in Distilled Water

Composition, Structure and Properties of Hard Alloy Components Made of Electroerosive Powders Prepared from Solid T5K10 Alloy Waste in Water

Composition, Structure and Properties of Hard Alloy Components Made of Electroerosive Powders Prepared from Solid T5K10 Alloy Waste in Water

WEAR-RESISTANT POWDER MATERIALS FOR PLASMA-POWDER SURFACING

Among powder surfacing materials with high hardness and resistance to abrasive wear, powders based on WC-TiC-Co systems, which are the basis of hard alloys, are among the most promising. (Research purpose) The research purpose is investigating wear-resistant powder materials for plasma-powder surfacing by electrodispersing solid alloy waste of the T30K4 brand in kerosene. (Materials and methods) We chose substandard carbide plates of the T30K4 brand as the starting material; lighting kerosene as the working fluid. We solved the tasks set in the work on the study of the composition, structure and properties of the obtained carbide powders using modern equipment and complementary methods of physical materials science. Electrodispersion of solid alloy waste was carried out on the original installation; the shape and morphology of the particle surface were studied on an electron-ion scanning microscope with field emission of electrons QUANTA 600 FEG; particle size composition ‒ on a laser particle size analyzer Analysette 22 NanoTec; X-ray spectral microanalysis of particles was carried out on an energy dispersive X-ray analyzer of EDAX company, integrated into a scanning electron microscope QUANTA 200 3D; phase analysis of particles was performed on an X-ray diffractometer Rigaku Ultima IV. (Results and discussion) A new technology for producing a carbide electroerosive powder suitable for plasma-powder surfacing has been developed and investigated, the effectiveness of which is confirmed by the properties of the proposed powder material: the spherical shape of powder particles; the average size of powder particles is 58.4 micrometers; powder particles with a uniform distribution of alloying elements: C, Co, Ti and W; powder particles include phases of carbides WC and TiC. (Conclusions) The conducted studies have shown that it is possible to obtain a wear-resistant powder alloy with a uniform distribution of alloying elements by the method of electroerosive dispersion of solid alloy waste of the T30K4 brand.

IMPROVING THE EFFICIENCY OF RESTORATION AND HARDENING OF THE WORKING BODIES OF TILLAGE MACHINES BY PLASMA-POWDER SURFACING OF CARBIDE ELECTROEROSIVE MATERIALS

The use of powders obtained from solid alloy waste as a highly solid dispersed component of the composition for plasma-powder surfacing will improve the quality, reliability and durability of plasma coatings of working bodies of tillage machines with a minimum of costs for powder materials. However, the properties of these plasma coatings have not been studied enough, so it is necessary to conduct comprehensive studies. (Research purpose) The research purpose is improving the technology of restoration and hardening of the working bodies of tillage machines by plasma-powder surfacing of powder materials obtained by electroerosive dispersion of solid alloy waste T30K4. (Materials and methods) Carbide powders made by electrodispersing solid alloy waste T30K4 in kerosene were used to obtain plasma coatings. We chose for the renovation object a pointed cultivator paw made of 40XC rolled steel. The obtained plasma coatings were studied using modern equipment and complementary methods of physical materials science. (Results and discussion) We have developed, tested and investigated a new technology for restoring and strengthening the working bodies of tillage machines using the example of a pointed cultivator paw by plasma-powder surfacing of carbide electroerosive powder materials. The effectiveness of the development was confirmed by the properties of plasma coatings: the microstructure of the coating has a fine-grained structure, without inclusions, uniform phase distribution and the absence of pores, cracks and discontinuities; elements W, Ti and Co in the coating are evenly distributed; phases of carbides WC and TiC are present; the grain size of the coatings is about 0.3 micrometers; the microhardness of the coatings is about 14245 megapascals. (Conclusions) The results of field tests showed that the resource of the working bodies of tillage machines, restored and strengthened with carbide electroerosion materials, is 1.25 times higher than the resource of new parts.

Physical and Mechanical Properties of a Tungsten-Titanium-Cobalt Alloy Produced by Spark Plasma Sintering of Hard-Alloy Electroerosive Powders Produced in Kerosene

Physical and Mechanical Properties of a Tungsten-Titanium-Cobalt Alloy Produced by Spark Plasma Sintering of Hard-Alloy Electroerosive Powders Produced in Kerosene

GRAIN SIZE OF ELECTROCORUNDUM SINTERED FROM DISPERSED WASTE ALUMINUM GRADE AD0E

To develop technologies for obtaining electrocorundum by spark plasma sintering of aluminum waste dispersed by electroerosion and to evaluate the effectiveness of their practical application, comprehensive the oretical and experimental studies are required. The purpose of this work was the grain size of electrocorundum sintered from dispersed aluminum waste of the AD0E brand. Electrodispersion of aluminum waste of the AD0E brand was carried out in distilled water at the original installation with a capacity of 65.5 UF discharge capacitors, a voltage at the electrodes of 200 V, a pulse repetition frequency of 200 Hz. As a result of exposure to short-term electrical discharges, particles of electroerosive powder of various sizes were formed in the water. Further, the fusion of the electroerosion charge was carried out in the spark plasma fusion system SPS 25-10 "Thermal Technology" (USA) at a pressure of 30 MPa, a temperature of 560 °C and a holding time of 3 minutes. Analysis of the microstructure of sintered electrocorundum showed that it has a fine-grained structure, without inclusions, uniform phase distribution and the absence of significant pores, cracks and discontinuities. The grain size of the studied alloys, determined using the SIMAGIS Photolab automated image analysis system and the OLYMPUS GX51 optical inverted microscope, was about 0.45 microns. The small grain size of the resulting electrocorundum is associated with the high dispersion of the initial electroerosion charge and the effect of "grain growth suppression" during spark plasma fusion due to the short working cycle time, high pressure and uniform heat distribution over the sample when exposed to pulsed electric current and the so-called "spark discharge plasma effect". The conducted studies will allow to perform resource conservation and import substitution in the production of electrocorundum from aluminum waste of the AD0E brand.

PROPERTIES AND COMPOSITION OF ELECTRIC EROSION POWDER FROM WASTE OF R18 TOOL STEEL

Currently, one of the promising methods of processing metal waste is electroerosive dispersion, which allows to obtain metal powder, including from the waste of tool steel P18. (Research Purpose) The research purpose is studying the properties and composition of the electroerosive powder obtained from the waste of P18 tool steel. (Materials and methods) Carried out grinding of waste steel P18 on an experimental installation by the method of electroerosive dispersion to obtain new powder materials. The process of electroerosive dispersion was carried out under certain installation modes. The granulometric composition of the particles of this powder was studied using the Analysette 22 NanoTec laser particle size analyzer. An experimental study was performed by dispersing ultrasound in a liquid. Metallography was studied using a Quanta 200 3D scanning electron microscope. X-ray spectral analysis was carried out using the scanning electron microscopy method with an energy-dispersion X-ray analyzer from EDAX, built into the Quanta 200 3D scanning electron microscope. The method of X-ray diffraction was used in X-ray diffraction analysis on a Rigaku Ultima IV diffractometer. (Results and discussion) It was shown that 50% of the powder particles correspond to the size of 44.13 micrometers. The elemental composition of the particles of the obtained metal powder from waste P18 was determined, the sample under study consists of the following chemical elements: carbon, oxygen, molybdenum, vanadium, chromium, iron and tungsten. The main phases of the powder material under study were established: Fe2W2C, FeV, Fe3O4. (Conclusions) Obtaining, studying the properties and composition of an experimental metal powder makes it possible to assess its potential for use in the production of products with specified characteristics, as well as hardening, restoration of car parts and agricultural machinery.

Results of X-ray studies of tungsten-titanium-cobalt alloy made by spark plasma sintering of carbide electroerosive powders obtained in kerosene

The results of the conducted experimental studies aimed at conducting X-ray studies of tungsten-titanium-cobalt hard alloy made by spark plasma sintering of carbide powders obtained by electroerosive dispersion of T5K10 hard alloy waste in kerosene are presented. It is shown that the obtained new hard alloys have a fine-grained structure, elemental and phase compositions identical to the original dispersible hard alloy of the T5K10 grade.

COMPARATIVE FRICTION TESTS OF BRONZE COATINGS FROM SECONDARY MATERIALS

Comparative tribotechnical studies of coated samples based on secondary composite materials on a friction machine is an important direction in the development of technologies to increase wear resistance and reduce friction in various industrial sectors. Secondary composite materials are obtained from production waste, which reduces costs and reduces the environmental burden. One of the examples of these materials are coatings obtained by welding and surfacing methods of electroerosive powders based on copper or a hard alloy from waste of tool industries or waste of non-ferrous metals and alloys. (Research purpose) The research purpose is performing a comparative analysis of tribotechnical properties of samples coated by secondary composite materials on a friction machine. (Materials and methods) Samples with a coating based on secondary materials and samples without a coating were produced for comparative studies. A machine was used to test materials for friction and wear AI 5018. (Results and discussion) It was found that coated samples based on secondary composite materials have higher wear resistance and less friction compared to uncoated samples. The coating based on secondary composite materials has a higher hardness and resistance to wear. It was found that with increasing load and sliding speed, the difference in wear resistance and friction between coated and uncoated samples increases. The coating based on secondary composite materials is particularly effective in conditions of high loads and sliding speeds. (Conclusions) Thus, comparative tribotechnical studies of coated samples based on secondary composite materials on a friction machine have shown that such coatings can be an effective way to increase wear resistance and reduce friction in various industrial sectors.

Evaluation of wear resistance of composite coatings obtained by electrodeposition of electrolytes-suspensions

The results of experimental studies aimed at assessing the wear resistance of composite coatings obtained by electrodeposition of electrolytes-suspensions with the addition of electroerosive powders made from waste high-speed steel grade P6M5 are presented. It has been experimentally established that the surface roughness parameter Ra of the obtained coatings is 2.14 microns, while the coefficient of friction on the path of 500 m is 0.14. It is noted that the introduction of highly solid particles of the electroerosive charge formed during the quenching of metal vapors in the working fluid during dispersion into the electrolyte increases the wear resistance of composite electrodeposited coatings.

ANALYSIS OF THE CHARACTERISTICS OF SINTERED PRODUCTS MADE OF CHROMIUM-CONTAINING ELECTROEROSIVE POWDERS

The article presents the results of the analysis of the characteristics of sintered productsmade of chromium-containing electroerosive powders. One of the main directions of the development of mechanical engineering technology at present is the improvement of existing and the development of new waste-free, environmentally friendly, material-saving production processes. Powder metallurgy plays a certain role in solving this problem. In recent years, much attention has been paid to the development of methods for the manufacture of high-density powder materials For the implementation of the planned studies, waste chromium-containing steels SHX15 andH13 have been selected. Powder materials were obtained by electrical erosion at the electro-erosive dispersion unit developed by the authors. Butyl alcohol was chosen as the working medium of dispersion. The powder was consolidated by the spark plasma sintering method using the spark plasma sintering system SPS 25-10 (Thermal Technology, USA). It is established that the microhardness of the sintered steel sample SHH15 is equal to 154 HV. The microhardness of the sintered steel sample H13 is equal to 461 HV. Itwas found that the porosity of the sintered steel sampleH13 is equal to 3.34%, and also that 95 % of the pores have a size of up to 2 microns. The porosity of the sintered steel sample SHH15 is 1.72 %, and also that 90 % of the pores have a size of up to 1 microns. According to the results of the research, it was found that the microhardness of the sintered sample made of steel SHH15 is lower than that of the sample made of steel H13. The porosity of a sample made of steel SHH15 is lower than that of a sample made of steel H13. Therefore, it can be concluded that sintered products made of powder material sta-li H13 have a harder surface and can be used in the production of small loaded parts.

Composition, structure and properties of hard alloy products from electroerosive powders obtained from T5K10 hard alloy waste in kerosene

The paper implements scientific and applied principles of coupling the technology of obtaining new powder materials from waste of hard alloys of the T5K10 brand by electroerosive dispersion and the technology of compacting them by SPS synthesis. The aim of the work was to study the composition, structure and properties of carbide products made from powders obtained by electrodispersing T5K10 alloy waste in kerosene. Electrodispersion of T5K10 alloy waste was carried out in lighting kerosene on a patented installation. The consolidation of the obtained powder was carried out by the spark plasma sintering (SPS) method using the spark plasma sintering system SPS 25-10. The choice of powders obtained by electroerosive dispersion of the T5K10 hard alloy waste was justified by its cost and properties. The resource of tungsten-titanium-cobalt hard alloys from T5K10 electroerosion powders is determined not only by the properties of the feedstock, but also by the technology of their production (SPS synthesis). Based on the conducted experimental studies, it can be concluded that the use of the spark plasma sintering method to produce products from powder obtained by electroerosive dispersion of the T5K10 alloy will ensure high performance of products (cutting tools) due to the uniformity of the surface, favorable structure and low porosity of the product. It is noted that hard alloys made of electroerosion dispersed T5K10 alloy particles obtained by spark plasma sintering under conditions of rapid heating and short working cycle duration have higher physico-mechanical properties compared to industrial alloys from which the initial powder particles were obtained by suppressing grain growth and obtaining an equilibrium state with submicron and nanoscale grain. This study was funded by the Russian Science Foundation, grant No. 22-29-00123, https://rscf.ru/project/22-29-00123/.

Structure and properties of additive products manufactured from electroerosion powders

The paper considers the possibility of using electroerosion metal powders based on the Co-Cr alloy with different properties in additive technologies. Use of these powders opens up great opportunities for improving the technical and economic characteristics of products, and will contribute to a significant increase in their reliability, durability, weight reduction, reduction of manufacture and operation costs. The economic efficiency of the use of electroerosion cobaltchromium powders is due to the use of waste and low energy-intensive technology for their production. The aim of this work is studying the technology of powder fusion obtained by electroerosion dispersion of cobaltchromium alloy waste in alcohol, on porosity, microhardness and roughness of additive products. The process of electrodispersion, i.e. grinding of the KKhMS "Cellite" alloy (63 % Co, 27 % Cr, 5 % Mo, 2 % Ni, 2 % Fe) was carried out on an original patented installation. After dispersion of cobalt-chromium alloy waste, its destruction occurred as a result of local exposure to short-term electrical discharges between the electrodes located in the working fluid, with formation of powder particles. Butyl alcohol was used as the working fluid. The fusion of electroerosion cobalt-chromium powders was carried out by plasma on the original installation for layer-by-layer deposition, which allows varying the technological parameters of the process: the nozzle transition speed (mm/min), the distance between the nozzle and the construction zone (mm), and the fusion temperature (°C). Based on a set of experimental studies, it was found that the melting temperature of particles of electroerosion cobaltchromium powder practically does not effect on varying in the elemental and phase composition of samples; at the same time, with an increase of the melting temperature, the pores size and their number decrease, as well as an increase of microhardness with decrease of the height of irregularities and roughness in general are observed. The research was conducted under financial support of the Russian scientific fund. The project number 17-79-20336P.

Properties of nickel-chromium alloy Kh20N80 sintered from electroerosive powders obtained in kerosene

The results of experimental studies of the composition, structure and properties of the Kh20N80 nickel-chromium alloy from a powder obtained by electroerosive dispersion in lighting kerosene are presented. It is shown that the method of spark plasma sintering of this powder can be used to obtain products with a surface with low porosity, high microhardness and a homogeneous favorable structure.

Structure and properties of sintered corrosion-resistant steel manufactured from electroerosive powders

This work solves the problem of saving expensive chrome. This problem is proposed to be solved by grinding their waste of corrosion-resistant steels and reusing them. One of the most promising and industrially non-applicable methods for grinding any electrically conductive material is the electroerosion method. Comprehensive theoretical and experimental research is required to develop technologies for the reuse of electroerosive powders and evaluate the effectiveness of their use. The purpose of this work was to study the structure and properties of sintered samples from electroerosive corrosionresistant powders obtained in butyl alcohol. To perform the planned studies, Kh13 steel waste was selected as the dispersible material. Waste steel Kh13 was processed at a voltage on the electrodes of 100–110 V; the capacity of the discharge capacitors is 45 UF and the pulse repetition rate is 65–75 Hz. Butyl alcohol was used as the working fluid. The resulting powder was consolidated by spark plasma sintering (SPS) using the SPS 25-10 spark plasma sintering system. Based on the conducted experimental studies aimed at studying the structure and properties of sintered samples from electroerosive corrosion-resistant powders obtained in butyl alcohol, the high efficiency of the spark plasma sintering technology is shown, which provides a uniform heat distribution over the sample, controlled porosity and high physical and mechanical properties with a short working cycle time and grain growth suppression. The work was supported by a scholarship of the President of the Russian Federation for young scientists and graduate students (SP-945.2019.1).

INVESTIGATION OF THE POROSITY OF THE VJ ALLOY SINTERED FROM ELECTROEROSIVE POWDERS OBTAINED IN WATER

The results of experimental studies of the porosity of the psevdosplav sintered from electroerosive powders obtained in distilled water are presented. It is shown that the use of the spark plasma sintering method for the production of products from the powder obtained by electrodispersion of the pseudoalloy VNJ 95 will ensure the porosity of the sintered samples of the order of 0.43% with an average micro-porosity of the samples of 349 HV

Assessment of wear resistance of hardened additive products made of electroerosive cobalt-chromium powder

Experimental studies of the wear resistance of hardened additive products made of electroerosive cobaltchromium powder obtained in alcohol are carried out. With a friction path of 500 m, the following was established: partial wear of the counterbody and adhesion of wear products of the sample to the counterbody; the size of the wear track of the sample; the depth of the profile of the wear groove of the sample surface; friction coefficient; wear of a counterbody made of steel and a hardened sample made of a cobalt-chromium alloy. Keywords: electroerosive cobalt-chromium powder, additive product, hardening, wear resistance. ageev_ev@mail.ru

X-ray spectral microanalysis of W-Ni-Fe pseudoalloy obtained from electroerosive powders

The results of X-ray spectral microanalysis of W-Ni-Fe pseudo-alloy, obtained from electroerosive powders, are presented. Consolidation of the obtained electroerosive powders was carried out by the method of spark plasma sintering using the SPS 25-10 spark plasma sintering system. Using an EDAX energy-dispersive X-ray analyzer built into a Quanta 600 FEG scanning electron microscope, characteristic X-ray spectra were obtained at various points on the sample surface and along a transverse section. As a result of the study, it was found that on the surface of the investigated sintered sample, tungsten, nickel and iron are contained as the main elements, and oxygen, copper and chromium are also present in small amounts.

Investigation of the structure and properties of reinforced additive products obtained from electroerosive cobalt-chromium powder

The analysis of the wear resistance characteristics of samples sintered from high-chromium electroerosive powders obtained in kerosene on a friction path of 500 m is performed. It was established experimentally that: there is a partial wear of the counterbody and the buildup of the products of wear of the sample on centralo; the magnitude of the wear track of the sample is 383,1 µm to 473,5 mm; the depth of the profile grooves of the wear surface of the sample is 5 microns; the coefficient of friction of the surface of the sample is from 0,228 to 0,826; the wear rate of the counterbody made of Stainless Steel AISI 420 and the sample made of sintered steel 12X17 are 0.016 and 1.138, respectively.