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ELECTRIC CONTACT PROPERTIES
OF MATERIAL CONTAINING REFRACTORY COMPONENTS.
MULTICOMPONENT MATERIAL
Authors: V.V. IZMAILOV, Dr. Sc., M.V. NOVOSELOVA, Cand. Sc.
Abstract: The results of a study of the main electrical contact characteristics of composite
powder materials on a copper basis containing fine diamond powder and a refractory
component in the form of a powder of molybdenum, tungsten, chromium, and a hard alloy
ВК6М are presented. The electrical resistivity, hardness, and electrical discharge wear of the
investigated samples are presented in absolute values and in a comparison with similar
characteristics of the reference material – electrical copper – depending on the composition of
the material, the polarity of the sample (sample – anode and sample – cathode) and the
relative position of the electrodes. Using the Harrington desirability function, the composite
with the optimum combination of operational properties is selected.
Keywords: composite diamond-containing copper material, refractory components,
electrical conductivity, electroerosive wear, Harrington desirability function.
INTEGRAL EVALUATION OF ELECTROCONTACT PROPERTIES
OF COMPOSITE MATERIALS USING HARRINGTON DESIRABILITY FUNCTION
Authors: V.V. IZMAILOV, Dr. Sc., M.V. NOVOSELOVA, Cand. Sc.
Abstract: The possibilities of using the overall Harrington desirability function as an integral
indicator of the quality of electrocontact composite powder materials are shown. The
calculation of the overall desirability function was performed for a number of copper-based
materials, taking into account the main operational characteristics: specific conductivity,
specific electrical discharge wear resistance and hardness. This function is universal
dimensionless criterion that does not depend on the dimensions of the quantities included in
it. According to the highest value of the desirability function, the samples with the optimal
complex of operational properties were selected. These turned out to be samples with a high
percentage of copper, the wear resistance of which was increased by the introduction of a
small amount of refractory components – fine diamonds and chromium.
Keywords: electrical contact material, powder composites, copper, refractory
components, conductivity, electroerosive wear resistance, hardness, desirability function.
INNOVATIVE MATERIALS AND COATINGS WITH THE EFFECT
OF ADAPTATION WHEN CUTTING METALS
Authors: A.M. MIGRANOV
, Postgraduate, M.Sh. MIGRANOV
, Dr. Sc.,
N.V. KOLOSOVA
, Postgraduate, E.Z. AKHMETOVA
, Postgraduate
Abstract: The literature on adaptive materials and wear-resistant coatings on cutting tools for
blade cutting is analyzed. The results of theoretical and experimental studies of the
operational properties of sintered tool materials based on high-speed steel with additional
alloying with additives, which provide a significant increase in the wear resistance of the
cutting tool, are presented and this phenomenon is explained from the point of view of
adaptation (self-organization) during friction by forming secondary structures. In this case,
the secondary structures play a dual role: lubricating and protective in the form of amorphous compounds.
Keywords: adaptive materials, high-speed steel, self-organization, alloying, friction,
thermodynamics, secondary structures.
INFLUENCE OF EXTERNAL ELECTRIC FIELD ON THE DEPTH
OF PENETRATION IN LASER WELDING OF STEELS
Authors: L.E. AFANASIEVA, Cand. Sc., I.Yu. KOBOZEV, undergraduate
Abstract: Possibilities of non-contact control of laser welding with the aid of external electric
field are considered. Schemes of coupling the field sources with laser technological
installations are given. Experimental results on the effect of external electric field on laser
welding of structural steel blanks are presented.
Keywords: laser processing, avalanche ionization, plasma torch, welding depth, electric field
JUSTIFICATION OF PARAMETERS FOR INSTALLING THE NOZZLE
OF A PEAT PNEUMATIC HARVESTER ABOVE THE UNDERLAYING SURFACE
Authors: А.L. YABLONEV, Dr. Sc., D.M. SCHERBAKOVA, Postgraduate
Abstract: The parameters affecting the efficiency of suction of peat crumb by pneumatic
harvesters are listed. Among them are the height of the nozzle above the underlying surface of
the deposit and the angle of the nozzle. Since there is very little information and
recommendations on the rational values of these parameters, a laboratory experiment was
carried out, using a specially created installation to assess the air flow rate, depending on the
distance fr om the nozzle, the angle of the nozzle and the height of the nozzle above the
underlying surface of the deposit. The results of the experiment are presented. It is shown,
that it is impossible to reproduce the zero distance from the nozzle to the underlying surface
in practice; therefore, it is recommended to lim it the height of 25 mm, which is equal to the
maximum size of the conditioned peat crumb. It is noted, that for more accurate results, it is
necessary to carry out the following series of experimental works to assess the parameters of
suction of peat chips with specific physical and mechanical characteristics by the nozzle.
Keywords: peat, pneumatic peat harvester, suction nozzle, air flow velocity,
anemometer, peat crumb, height of the nozzle above the underlying surface of the deposit.
ANALYSIS OF THE INFLUENCE OF INACCURACY
OF ARRANGEMENT AND HEIGHT OF CUTTERS ON THE WORKING BODY
OF A PEAT MILLING MACHINE ON THE FREQUENCY PROPERTIES
OF THE RESISTANCE TORQUE
Authors: K.V. FOMIN, Dr. Sc.
Abstract: In the article a model of the moment of resistance is offered which takes into account
periodical character of interaction of cutters with a peat deposit, random conditions and
modes of machine operation, influence of errors of blade angles on the cutter body and their
height, connected with inaccuracy of manufacturing and assembly of an executive body as
well as with wear or irreversible deformations of cutting elements. On its basis expressions
for calculation of spectral density of the torque are received and influence of errors on its
frequency properties is investigated. Deviation of geometrical parameters from the «ideal»
values leads to appearance of additional components at frequencies multiple of the cutter
angular velocity in the spectral momentum density. Their magnitude is proportional to the
total error of blade placement by angle, as well as proportional to the total value of the ratio of
blade height errors to feed rate. These factors should be taken into account when working
with low feeds and working tools with a large number of cutting elements; when calculating
dynamic loads in the elements of a structure if their natural frequencies are the same or close
to the cutter angular velocity or multiple of it.
Keywords: peat milling unit, cutter, blade location error, cutter height error, resistance
torque, load model, spectral density.
COMPREHENSIVE DIAGNOSTICS
OF FRICTION UNITS OF PEAT MACHINES
Authors: I.V. GORLOV, Dr. Sc.
Abstract: The article presents the results of a study of the technical condition of rolling bearings,
Вестник Тверского государственного технического университета.
Серия «Технические науки». № 4 (12), 2021
65
the studies were carried out on a model of a milling unit. Ensuring the required reliability of
technological machines is impossible without the use of systems for monitoring the state of
friction units. For this, it is proposed to install sensors for temperature and vibroacoustic
control in critical units of peat machines, which will allow, based on a comprehensive
analysis of the state of friction units of the machine, to identify at early stages and eliminate
the causes of failures. The use of a comprehensive analysis of the parameters of the technical
state of the main friction units of peat machines allows, on the basis of the data obtained, to
predict with high accuracy the operating time before repair, preventing failures during the
peat mining season
Keywords: friction units, peat machines, diagnostics, reliability.
MACHINE LEARNING MECHANISM
IN AUTOMATED DESIGN SYSTEMS
Authors: G.B. BURDO, Dr. Sc., A.N. BOLOTOV, Dr. Sc.
Abstract: The article presents the results of a study describing the way knowledge is represented
in computer-aided design and process control systems for single and small-scale.
Knowledge is proposed to be represented in the form of three types of functions inherent in
human thinking. The formation of new knowledge based on previous experience is
shown.
Keywords: technological processes, automated design, artificial intelligence,
knowledge descriptions.
SIMULATION OF GAS LASER CUTTING
OF HIGH-ALLOY STEEL
Authors: D.A. ZORENKO, Cand. Sc.
Abstract: The article presents the main results of CAE-modeling of the process of gas laser
cutting of high-alloy steel. The features of the creation of computational models and the
process parameters obtained with their help are considered. The pictures of the temperature
fields and the distribution of the safety factor over the yield strength of steel have been
obtained.
Keywords: aser cutting, temperature field, finite element method, steel, laser cutting,
calculation model.
APPLICATION FEATURES OF THE SENSORS FOR MONITORING
THE ARC PARAMETERS OF THE CARBON NANOTUBE SYNTHESIS PLANT
BY THE PLASMA CHEMICAL METHOD
Authors: I.M. ZHABBAROV, postgraduate, A.V. YUDIN, Dr. Sc.
Abstract: The article devoted to the problem of electromagnetic compatibility of sensors for
monitoring the parameters of the plasma torch arc. A brief review of publications with the
causes of interference and ways to eliminate them is made. The influence of the arc current of
the plasma torch on the current measuring sensor is analyzed and the magnitude of the
induced EMF is calculated. A full-scale experiment was carried out with the measurement of
the induced EMF using an oscilloscope. Recommendations for improving the conditions of
electromagnetic compatibility have been developed.
Keywords: plasma torch, sensor, distortion, power source, electromagnetic
compatibility, synthesis carbon nanotubes.
ASSESSMENT OF HAZARDOUS AND HARMFUL PRODUCTION FACTORS
IN ERGATIC SYSTEMS BY THE METHOD OF DISPERSION ANALYSIS
Authors: N.M. PUZYREV, Cand. Sc., D.V. MARTYNOV, Cand. Sc.,
N.B. BARBASHINOVA, Lecturer, A.S. YEMTSEV, postgraduate
Abstract: The characteristics of hazardous and harmful production factors in such an ergatic
system as electric welding production, their harmful effects on personnel are given. Based
on the analysis of variance, a relationship is established between the impact of these factors
on personnel and the partial loss of their working capacity, taking into account individual
characteristics. A method for solving problems of assessing the level of safety at work using
the methods of analysis of variance is proposed, showing that the improvement of the
economic performance of an enterprise depends on the creation of safer working conditions,
leading to a decrease in losses of working time.
Keywords: system analysis, ergatic system, industrial safety, hazardous production
factor, harmful production factor, analysis of variance.