Methods for obtaining metal powder materials

Author(s):  
Ivan A. Shemberev ◽  
Vitaliy A. Zuyevskiy

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.

Author(s):  
Anna P. Karpunicheva ◽  
Dar’ya A. Lebedeva

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.


Author(s):  
Dinar R. Masalimov ◽  
Roman R. Galiullin ◽  
Rinat N. Sayfullin ◽  
Azamat F. Fayurshin ◽  
Linar F. Islamov

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.


2020 ◽  
Vol 4 (141) ◽  
pp. 123-131
Author(s):  
IL’YA ROMANOV ◽  

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.


2021 ◽  
Vol 3 (144) ◽  
pp. 64-71
Author(s):  
Yuriy V. Katayev ◽  
◽  
Valeriy S. Gerasimov ◽  
Vladimir I. Ignatov ◽  
Zoya N. Mishina ◽  
...  

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.


2018 ◽  
Vol 936 ◽  
pp. 198-203
Author(s):  
Liang Xu ◽  
Yi Bo Liu ◽  
You Hong Sun

With diamond particles, metal powders and a special soft material as raw materials, this paper introduced some diamond bits to drill the superhard materials such as granite. Besides, the biology non-smooth theory was applied to the design of bit, and a new type of bit which is called bionic bit was introduced about its principle and manufacturing method. HYPERLINK "http://dict.cnki.net/dict_result.aspx?searchword=%e6%95%b0%e5%80%bc%e6%a8%a1%e6%8b%9f&tjType=sentence&style=&t=numerical+simulation" Numerical simulations and field tests of bionic bits showed that the optimalizing non-smooth degree was the most important factor of the design of bionic bit. By ANSYS finite element calculation when the non-smooth degree is 12.6%, the drilling bit wear is the smallest, 63% less than the ordinary bit. This paper prepared four bionic bits with the non-smooth degree 13% and four ordinary bits to drill the granit in gold mine, the average life and drilling speed of bionic bits increased by 29.8% and 21.3% more than ordinary bits.


2015 ◽  
Vol 20 (2) ◽  
pp. 79-85
Author(s):  
Ioan Virca

Abstract The paper presents how is processed the data resulted from application of pulsed optical superficial treatments on surfaces of materials made of metal powders. The parameters of the electrotechnological regime work are variable in the experimental program, namely the distance between the axis focal energy sources and surfaces play, the number of energy pulses applied to the voltage pulse of optical radiation, which causes a statistical analysis more complex, after which it will precise drawing lessons that will lead to a calculation microhardness model in the superificial layer of material.


2020 ◽  
Vol 989 ◽  
pp. 270-275
Author(s):  
Lyudmila Ryabicheva ◽  
Valery V. Dyadichev ◽  
Yu.N. Nikitin ◽  
Aleksandr Dyadichev

The paper presents the materials on researching the use of current conductor copper waste for getting new functional materials. The changes of maximum deformation ratio, density, microstructure and hardness of powder copper preforms at different temperatures and deformation rates have been studied. The result is that the value of the maximum deformation ratio depends on kinetics of dynamic weakening processes. The change of the microstructure depending on the temperature and deformation ratio has been scrutinized. It has been established that the most fine-grained structure was got at the temperatures of dynamical recovery and recrystallization. The temperature intervals of stamping for manufacturing products by pressing are recommended. On the basis of experimental researches a resource-saving manufacturing method of producing axisymmetric details of high density from powder copper material with the use of maximum deformation ratios has been elaborated.


Author(s):  
Il’ya V. Romanov ◽  
Roman N. Zadorozhniy

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.


Author(s):  
Il’ya V. Romanov ◽  
Roman N. Zadorozhniy

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.


2008 ◽  
Vol 594 ◽  
pp. 138-149 ◽  
Author(s):  
Muh Ron Wang ◽  
Che Jui Yang ◽  
Jian Duen Huang ◽  
Tien Chu Lin ◽  
Ming Shen Sheu

Uniform and spherical metal powders have been widely used in many industrial applications. This paper investigates the control of particle size and size distribution by the impingement of the molten spray on the substrate with different geometries. The idea is to combine the atomization process with the classification process. Result shows that a significant reduction of the particle size occurred when the substrate was placed in the spray jet. The mean particle size was lowered to 8.0μm with a low transmission ratio of the spray jet in the existence of the ring type substrate. The particle size increased from 8.78μm to 12.67μm as the transmission ratio was increased from 13.92% to 75.80%. The reduction in particle size was due to the effect of the blockage of the substrate on the spray. The particle size increased from 6.72μm to 6.98μm when the disk-type substrate was placed at Z = 150mm and 200mm, respectively. The particle size of this case was smaller than the case with ring type substrate because the transmission ratio of the disk type substrate was lower. The percentage of small particles (i.e., V15-) were higher than 60% and the percentages of V25-45 were 4.19% and 0.37% when the disk-type substrate was placed at Z=150mm and Z=200mm, respectively, indicating that almost all of the particles were below 25μm under these conditions. Hence this technique is very effective in controlling the particle size in the metal powder production.


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