Powder materials and methods for their preparation

2020 ◽  
pp. 108-118
Author(s):  
Anna P. Karpunicheva ◽  
Dar’ya A. Lebedeva
Keyword(s):  
Powder Metallurgy ◽  
Fire Hazard ◽  
Point Of View ◽  
Research Purpose ◽  
Powder Materials ◽  
Metal Powders ◽  
Resource Saving ◽  
Technical Literature ◽  
Mechanical Methods ◽  
Information Materials

Powder metallurgy, along with other knowledge-intensive industries, is one of the priority areas of high-quality, modern, technologically advanced production, one of the main tasks of which is resource-saving technologies. (Research purpose) The research purpose is in analyzing the existing methods for obtaining metal powders and metal-like compounds in order to review and systematize information. (Materials and methods) The methodological basis is the scientific and technical literature on the topic of manufacturing materials for powder metallurgy. The solution of the problem was carried out by means of comparative and logical analysis based on theoretical and empirical methods of scientific research. (Results and discussion) There are two groups of methods for producing metal powders: mechanical and physical-chemical, as well as methods for manufacturing metal-like compounds. Each of the production methods is analyzed from the point of view of technology, equipment, feasibility of application and the resulting materials. (Conclusions) When manufacturing powders by mechanical methods, there is a high probability of particles of grinding bodies or linings entering the final product. Dispersion allows to automate the process, adjust the properties of powders at a fairly low energy consumption. Physical and chemical methods of production require complex equipment, as well as compliance with safety regulations due to high fire hazard.

Methods for obtaining metal powder materials

2019 ◽  
pp. 137-145
Author(s):  
Ivan A. Shemberev ◽  
Vitaliy A. Zuyevskiy
Keyword(s):  
Metal Powder ◽  
Raw Materials ◽  
Research Purpose ◽  
Powder Materials ◽  
Metal Powders ◽  
Resource Saving ◽  
Important Place ◽  
Manufacturing Method ◽  
New Energy ◽  
Almost All

In practice, a large number of methods for obtaining metal powders are known, their diversity is due to the technological capabilities of manufacturing powders in several ways from different types of raw materials, as well as different requirements for the characteristics of powders for various fields and conditions of application. Metal powders in most cases are a secondary product, the properties of which are affected by the manufacturing method, so the theoretical foundations of their production occupy an important place in the processes of powder metallurgy. (Research purpose) The research purpose is in analyzing existing methods for obtaining metal powder materials and develop a new energy-and resource-saving method for obtaining powders, such as electroerosive dispersion. (Materials and methods) Authors have studied literary sources, works of prominent scientists and specialists on the subject of research. (Results and discussion) The article presents the main methods of powder production: mechanical and physical-chemical, as well as a relatively new method of electroerosive dispersion. More productive methods of obtaining powders are being introduced into production, in which considerable attention is paid to methods of cleaning powders from oxygen and carbon, controlling the shape of particles and their sizes. (Conclusions) Analysis of existing methods for obtaining powder materials has shown that they do not fully meet the requirements for quality composition of new technological solutions, in particular, additive technologies. The development of fundamentally new methods for obtaining powders, such as electroerosive dispersion, is a promising direction that makes it possible to obtain powders from almost all conductive materials, adjusting the size and shape of granules.

Investigation of pre-sprayed powders for electric contact welding

2020 ◽  
pp. 143-149
Author(s):  
Dinar R. Masalimov ◽  
Roman R. Galiullin ◽  
Rinat N. Sayfullin ◽  
Azamat F. Fayurshin ◽  
Linar F. Islamov
Keyword(s):  
Adhesion Strength ◽  
Electrical Contact ◽  
Research Purpose ◽  
Flame Spraying ◽  
Powder Materials ◽  
Electric Contact ◽  
Metal Powders ◽  
Unstable Flow ◽  
Gas Flame ◽  
Contact Welding

There are a number of difficulties in the electrical contact welding of powder materials: shedding of powder from the surface of a cylindrical part, impossibility of hardening the layer during welding due to flushing of the powders with coolant and unstable flow of powder into the welding zone. One solution is pre-spraying the powder in some way. (Research purpose). The research purpose is investigating the possibility of electric contact welding of metal powders preliminarily sprayed by a gas-flame method, namely, adhesion strength and losses during preliminary gas-flame spraying of powders. (Materials and methods) Powders of grades PG-NA-01, PrKhIIG4SR, PRZh3.200.28 were sprayed onto flat samples of St3 steel, polished to a roughness of Ra 1.25. The strength of powder adhesion to the base was studied by the cut method. (Results and discussion) The percentage loss of the powder as a whole is 3-23 percent for all the distances studied. The greatest powder losses appear at a distance of more than 180 millimeter from the tip of the burner for powders of grades PG-NA-01 and PrKhIIG4SR. The smallest powder losses were observed for PrZh3.200.28 powder, which totaled 3-7 percent. The maximum adhesion strength of the sprayed powders to the surface was 22.1 megapascals' when spraying the PG-NA-01 powder. The adhesion strength of powders of the grades PrKhIIG4SR and PrZh3.200.28 is small and amounts to 0.2-3 megapascals'. (Conclusions) The use of preliminary flame spraying of powders for their further electric contact welding is possible using PG-NA-01 grade powder, while the best adhesion to the base (that is more than 20 megapascals') is achieved with a spraying distance of 120-140 millimeter. The smallest powder losses during flame spraying are achieved at a spraying distance of 100-160 centimeters', at which the powder loss for the studied grades was 4-12 percent.

INCREASING THE WEAR RESISTANCE OF THE WORKING BODIES OF AGRICULTURAL MACHINES BY THE HDTV METHOD WITH ADDING POWDER OF THE EED METHOD

2020 ◽  
Vol 4 (141) ◽  
pp. 123-131
Author(s):  
IL’YA ROMANOV ◽  
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
High Frequency ◽  
Machine Building ◽  
Abrasive Wear Resistance ◽  
Research Purpose ◽  
Powder Materials ◽  
Agricultural Machinery ◽  
Resource Saving ◽  
Working Bodies

The development of energy and resource-saving methods and technologies for strengthening and restoring the working bodies of agricultural machinery will increase their abrasive wear resistance and durability by using materials from machine-building waste and reduce the cost by 10-30 percent without reducing operational characteristics. (Research purpose) The research purpose is in increasing the abrasive wear resistance and durability of cultivator legs by surfacing powder materials obtained by electroerosive dispersion from solid alloy waste by high-frequency currents. (Materials and methods) Authors obtained a powder for research on their own experimental installations of the CCP "Nano-Center" of electroerosive dispersion from waste of sintered hard alloys of the T15K6 brand. The microhardness of powders and coatings on microshifts was measured using the PMT-3 device, and the hardness of coatings with the KMT-1 microhardometer was measured using the Rockwell method according to GOST 9013-59. The microwave-40AV installation was used to assess the wear resistance of materials of working bodies of tillage machines. (Results and discussion) In the course of laboratory wear tests the relative wear resistance of samples hardened by high-frequency surfacing currents significantly exceeds the wear resistance of non-hardened samples made OF 65g steel, accepted as the reference standard. (Conclusions) Based on the results of experimental studies, the article proposes a new resource-saving technological process for strengthening the working bodies of agricultural machinery through the use of materials from machine-building waste, which allows increasing the abrasive wear resistance of working bodies by 1.5-2 times due to the use of tungsten-containing materials.

OPTIMIZATION OF THE REPAIR AND MAINTENANCE BASE OF THE AGRO-INDUSTRIAL COMPLEX

2021 ◽  
Vol 3 (144) ◽  
pp. 64-71
Author(s):  
Yuriy V. Katayev ◽  
◽  
Valeriy S. Gerasimov ◽  
Vladimir I. Ignatov ◽  
Zoya N. Mishina ◽  
...  
Keyword(s):  
Critical Period ◽  
The State ◽  
Research Purpose ◽  
Industrial Complex ◽  
Resource Saving ◽  
Technical Literature ◽  
Lack Of Information ◽  
Technological Level ◽  
Almost All ◽  
Technical Readiness

The repair industry in almost all countries has entered a critical period, characterized by the need to combine and use various strategies and technologies for maintenance and repair of new equipment, as well as equipment produced many years ago. (Research purpose) The research purpose is in analyzing the state of the repair and maintenance base of the agro-industrial complex and justifying the possibilities of its modernization using intelligent technologies. (Materials and methods) Authors used methods of generalizing data from various services of agro- industrial formations of individual regions, materials of scientific and technical literature and research developments, studied data on the practical use of modern resource-saving technologies by engineering services of the agro-industrial complex of the regions when carrying out repairs and service and technological services. (Results and discussion) The lack of information about the state of the repair and maintenance base makes it difficult to determine all the criteria associated with the transition of manufacturers to a contract of the entire life cycle. Obtaining information about the state of the repair and maintenance base of the agro-industrial complex is a very important stage that contributes to the modernization of this base and attracting not only the governments, but also agricultural machinery manufacturers to modernization. (Conclusions) The technological level of the enterprises of the repair and maintenance base of agriculture has significantly decreased in recent years, and this has affected the decline in technical readiness indicators, which confirms the need to conduct research and implement in practice the main measures related to the modernization of the specified repair and maintenance base.

Роль декоративно-отделочных, облицовочных материалов стен и потолков, покрытий полов в развитии пожара и формировании его опасных факторов

2020 ◽  
Author(s):  
Aleksey Shebeko ◽  
Natalia Konstantinova ◽  
Olga Krivoshapkina
Keyword(s):  
Kinetic Parameters ◽  
Building Materials ◽  
Fire Hazard ◽  
Fire Risk ◽  
Point Of View ◽  
Fire Load ◽  
Technical Literature ◽  
Wood Composition ◽  
Heat Loads ◽  
Facing Material

Проанализирована роль декоративно-отделочных, облицовочных материалов и покрытий полов в формировании опасных факторов пожара (ОФП). Проведены расчеты распространения ОФП в модельном помещении с учетом вклада облицовочного материала стен и потолка. Показана возможность применения рассмотренного подхода для моделирования условий (стандартных и нестандартных) испытаний строительных материалов и конструкций на пожарную опасность (например, фасадных систем) и гибкого нормирования при использовании декоративно-отделочных, облицовочных материалов и покрытий полов в зданиях и сооружениях.Article presents the study of the possibility to describe thermal decomposition and thermal oxidation processes of fire load finishing materials by means of the kinetic parameters. These parameters are defined by results of termogravimetric analysis for modeling the dynamics of fire development. Nowadays the problem of modeling the distribution of hazardous fire factors (HFF) in buildings and constructions has wide practical application, however techniques of HFF modeling do not take into account as fire load finishing and facing materials of building and construction premises in development of a fire, so they are not considered at an estimation of safe evacuation of people from buildings and constructions as well as at calculation of fire risk, too. When describing a seat of fire there are used fire hazard indicators having essential uncertainty according to the technical literature sources and experimental data while formation should be based on the possibility of their thermodestruction and thermooxidation under the influence of heat loads of various intensity. At the same time, the speed of the specified processes should be interconnected with values of heat loads. The presented work is of current importance because it is necessary to describe thermodestruction and thermooxidation processes of fire load material at modeling the dynamics of HFF distribution in buildings and constructions by means of kinetic parameters received as the results of thermogravimetric analysis. On the example of calcium silicate and wood composition there are carried out calculations of HFF distribution in a test premise taking into account the contribution of wall and ceiling facing material. There is shown the prevailing, in comparison with a seat of fire, contribution of wall and ceiling facing material to HFF formation at its initial stage which is especially important from the point of view of ensuring safe evacuation of people at fire in buildings and constructions. On the basis of the conducted analysis of research results there are developed proposals for applying the considered approach to model conditions for (standard and non-standard) tests of building materials and structures for fire hazard (for example, front systems) and flexible rationing of use of decorative - finishing and facing materials as well as floor coverings in buildings and structures.

Influence of ultrasound and surface-active substances on the dispersion of metal powders

2020 ◽  
pp. 91-97
Author(s):  
Il’ya V. Romanov ◽  
Roman N. Zadorozhniy
Keyword(s):  
Ultrasonic Field ◽  
Research Purpose ◽  
Powder Materials ◽  
State University ◽  
Metal Powders ◽  
Adhesion Properties ◽  
Noticeable Improvement ◽  
Negative Feature ◽  
Powder Particles ◽  
Material Studies

It is scientifically proven that reducing the particle size in metal powders leads to a noticeable improvement in the materials properties. The shape of powder particles and their nanoscale are of great importance in sintering technologies for the formation of dense homogeneous alloys, as well as in additive manufacturing. A negative feature of nanoparticles is that they can stick together and form agglomerates and aggregates. (Research purpose) The research purpose is in proving the influence of ultrasound on the dispersion of metal powders, as well as studying the issue of preventing sticking of particles of powder materials with the help of surfactants. (Materials and methods) The article presents conducted tests at the Lomonosov Moscow state University. Authors used three brands of powder obtained by electroerosive dispersion (T15K6, Lc38mts2 and Brazh9-12), a high-class portable digital ultrasound device of the Logiq-E series, a scanning electron microscope of the DESK-TOP AURA series, and a Spectro-photocolorimeter “Spekol-210”. (Results and discussion) A suspension of metal powders in distilled water was subjected to ultrasound for 1, 5 and 10 minutes. The percentage of particles of three fractions was studied on a scanning microscope: 40-150; 150-300 and more than 300 nanometers. Polyethylene glycol PEG-35 was introduced into the suspension in different proportions to study the effect of surfactants. Solutions were studied using a spectrophotometric method to determine the adsorption of surfactants on the filler. (Conclusions) The effect of ultrasound on the dispersion of metal powders has been proved. It was hypothesized that conducting the process of electroerosive dispersion in an ultrasonic field can provide a better quality powder material. Studies with the use of surfactants have shown the prospects of their use for adsorption modification of metal fillers in order to improve the adhesion properties.

Isolation of fine powder faction obtained by electroerosion dispersion method

2020 ◽  
pp. 119-127
Author(s):  
Il’ya V. Romanov ◽  
Roman N. Zadorozhniy
Keyword(s):  
Fine Particles ◽  
Fine Fraction ◽  
Fine Powder ◽  
Physical And Mechanical Properties ◽  
Ceramic Filter ◽  
Research Purpose ◽  
Powder Materials ◽  
Metal Powders ◽  
Large Spread ◽  
Wide Range

The fundamental properties of metal powders with small particles change, which opens up a wide range of applications of such materials. Currently, nanopowders are used in many industries to improve the quality of the resulting products. (Research purpose) The research purpose is in isolating a fine fraction of metal powders obtained by electroerosive dispersion for further experiments with this material, and also proving the possibility of obtaining such fractions by this method. (Materials and methods) A fine fraction of metal powders obtained by the method of electroerosive dispersion was isolated, which proved its effectiveness in obtaining conductive powder materials with the desired final physical and mechanical properties. This method results in a fairly large spread across fractions. Authors received material for research on experimental installations of the "Nano-Center" Center for Collective Use. The article presents the methods of experimental research of fractional composition on the example of metal powders of hard alloy grades T15K6 and VK8, copper powder M1, brass powder LTs38MTsS2 and bronze powder BrAZh9-12 obtained by electroerosive dispersion. (Results and discussion) The metal powder was divided into three fractions, depending on the particle size: more than 0.071 mm, from 0.02 to 0.071 mm and less than 0.02 mm. The presence of fine particles of less than 1.5 microns in the total mass of the studied powders was proved using a membrane method with a ceramic filter. Sedimentation showed specific sizes of minimal particles (from 86.4 to 116 nm). (Conclusions) Based on the results of experiments, it is possible to obtain metal powders of a fine fraction using the method of electroerosive dispersion.

Mathemathical Model of Powder Sintering with Nano- and Microadditives

2011 ◽  
Vol 312-315 ◽  
pp. 1204-1207 ◽  
Author(s):  
I.E. Ignatiev ◽  
V.I. Bulanov ◽  
A.N. Dmitriev
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Powder Metallurgy ◽  
Thin Layer ◽  
Powder Materials ◽  
Metal Powders ◽  
Powder Metal ◽  
Powder Sintering ◽  
Metal Sintering

One of the problems of powder metallurgy still remaining is the problem of billets shrinkage at sintering. Introduction of a small impurity coating consisting of a very thin layer of the particles on the basic powder is a known method of compacting at sintering of powder materials. The mathematical modeling of such a process encounters ambiguity some issues of the sintering theory of metal powders, therefore forcedly leans on experiments. A mathematical model of powder metal sintering with nano- and microadditives is presented.

Calculation of plasma centrifugal spraying parameters of fine granules of heat-resistant nickel alloys

2020 ◽  
pp. 471-474
Author(s):  
M.G. Yagodin ◽  
E.I. Starovoytenko
Keyword(s):  
Powder Metallurgy ◽  
Nickel Alloys ◽  
Dynamic Pressure ◽  
Calculated Data ◽  
Powder Size ◽  
Metal Powders ◽  
Heat Resistant ◽  
Gas Dynamic ◽  
Spraying Parameters ◽  
Wide Range

The equipment for the production of wide range of metal powders purposed for powder metallurgy is described. The possibility for producing of powders by the plasma centrifugal spraying is considered taking into account the gas dynamic pressure. The calculated data on the powder size for different materials are given.

Life cycle of self-propelled machinery with waste generation at its disposal

2020 ◽  
pp. 28-35
Author(s):  
Valeriy S. Gerasimov ◽  
Vladimir I. Ignatov ◽  
Konstantin G. Sovin
Keyword(s):  
Life Cycle ◽  
Life Cycles ◽  
The State ◽  
Research Purpose ◽  
Industrial Complex ◽  
Agricultural Machinery ◽  
Resource Saving ◽  
Secondary Resources ◽  
Branch System ◽  
Additional Funding

According to forecasts for 2022, the number of self-propelled agricultural machinery that will fail will be about 100 thousand units. This will have a significant impact on the overall productivity in the field of agricultural production and will require additional financial costs for effective resource-saving environmental-oriented utilization of agricultural machinery with the maximum recovery of secondary resources in the processing of its components. (Research purpose) The research purpose is considering the main life cycles of machinery, including agricultural, and determining the possibility of obtaining secondary resources in the recycling of components of machinery and equipment. (Materials and methods) The authors found that the establishment of an industry-wide recycling system would allow the reuse of usable and recovered parts obtained from decommissioned equipment, as well as receive additional funding from the sale of secondary resources. The authors have found that for the functioning of the whole system, it is necessary to work with a large amount of data related to the ongoing recycling processes, as well as constantly monitor changes in the state and properties of materials. They also found that the maximum use of digital technology is the only way to combine all these requirements and make the system work. (Results and discussion) The article reviews the key points of the use of life cycle method for equipment, including agricultural, reviews the state of machine and tractor park of agro-industrial complex, shows the possibility of using resource-saving ecologically oriented branch system of recycling of agricultural machinery, as well as the movement of waste and material flows in the processing components of utilized machines. (Conclusion) The article presents recommendations on the possibility of efficient disposal of equipment, including agricultural, with the maximum recovery of secondary resources from recycled waste.

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