Abstract Formulas for the probability of filling of surface texture bounded by convex and concave parabolic segments are derived on the basis of geometric and mathematical modeling. The probability characteristics are calculated and compared for the convex and concave segments: they differ by a factor of two. That permits the use of probability characteristics to assess surface texture.

Abstract The stress state of teeth in peripheral sections of the contact zone must be taken into account in calculations of hardened gears with local tooth contact.

Abstract The geometric parameters of surface texture for machine parts and mechanisms mandated by international and Russian standards do not always permit satisfactory assessment of the shape of the irregular microprojections, their frequency, and the convexity and concavity of their component surfaces. Studies of surface texture rarely employ a physical coefficient associated with the filling of the

Abstract For surface texture with microprojections bounded by concave semicircles in two-dimensional space, analytical formulas are derived for the probability of filling of the surface layer with material, both within cross sections and layers and over the volume as a whole. Comparison of probability estimates obtained by graphical and analytical methods permits judgments regarding their correspondence

Abstract Experimental values are derived for the tribological characteristics of EN-GJV-400 cast iron, as well as its surfaces modified by melting, alloying with copper and nickel, and tungsten inert gas (TIG) welding in a high-frequency magnetic field. The latter process considerably improves the wear resistance.

Abstract The effectiveness of repeated shot treatment in increasing the fatigue strength of high-strength 30ХГСН2А steel parts is established experimentally. Repeated shot treatment not only restores the initial life but increases it significantly.

Abstract Impact flexure and indentation of metals is considered. A test bench for failure assessment is developed, for the example of steel 45 at low temperatures. In this method, acoustic emission pulses are classified; an artificial neural network is employed. The fractographic data for impact flexure correlate well with the results of pulse recognition.

Abstract Attention focuses on the heat propagation in metal polycrystals where the grain or subgrain size affects the strengthening—as a result of surface plastic deformation, for example. Effects associated with change in grain size are described by the Hall–Petch phenomenological model. A differential equation is obtained for the steady heat propagation in metals and alloys where plastic deformation

Abstract The applicability of distributed ledger technology (DLT) in PLM systems at production enterprises is considered. Potential benefits of this approach include decentralization, openness, and interoperability of automation systems for production enterprises.

Abstract On the profilograms obtained for real surfaces machined by different methods, the microprojections resemble elements of sinusoids and cosinusoids. Accordingly, it is of interest to investigate geometric models of such rough surfaces. The analytical expressions obtained for the probability of filling of the rough surface layer with material permit comparison of the results for microprojections

Abstract Models based on regression analysis for predicting the operational efficiency of high-pressure roller crushers are considered. A systematized and structured production database is created and statistically analyzed. The consistency of the data is verified. The parameters with the greatest influence on the productivity are identified. The basic structure of the mathematical models is determined

Abstract Basic principles are outlined for the construction of an effective smart management system permitting the manufacture of unique products.

Abstract A model is proposed for estimating the efficiency of communication by robots capable of social interaction with humans. A generalized index of the robot’s effectiveness in communication is derived. That index is calculated by means of a fuzzy deduction module.

Abstract The thermal influence of the tooth geometry in a conical gear is considered for the case of milling by a cutting head. Formulas are derived for the maximum temperature and the temperature field in cutting as a function of the geometric parameters of the tooth. On that basis, research in a virtual environment corresponding to the actual conditions is possible at preproduction, and the thermal

Abstract For surface texture with microprojections bounded by a mixture of concave and convex semicircles in two-dimensional space, analytical formulas are derived for the filling probability of the surface layer, both within cross sections and over the volume as a whole. Comparison of probability estimates obtained by graphical and analytical methods indicates excellent agreement. Comparison of the

Abstract A design procedure for nonstationary production systems is outlined. On the basis of the generalized mathematical model, specific models for components of nonstationary systems are developed. In particular, a model for slipway finishing of a part prior to welding in submarine hulls is proposed.

Abstract Analysis of the texture profile of surfaces machined by different methods shows that the geometric parameters of the surface microprojections do not fully characterize their shape, repetition frequency, height, and other properties. Instead, a potential comprehensive characteristic is the filling probability of the rough surface layer over the thickness and the volume as a whole. This parameter

Abstract The water-jet cutting of fiberglass is studied experimentally. On that basis, the splitting of the fiberglass sheet is related to the cutting conditions. That permits decrease in fiberglass waste and improvement in product quality.

Abstract Thermofrictional cutting with pulsed cooling is investigated by the finite-element method, using Deform 3D Machining software. On that basis, the cutting mechanism proposed earlier is confirmed.

Abstract Structural-parametric models of electroelastic actuators for nanomechanics are presented. The structure of the actuators is established, and their transfer functions are determined. Transfer functions are derived for a piezo actuator with a generalized piezo effect. The change in elastic pliability and rigidity of the actuator is established in the case of voltage control and also current

Abstract A kinematic model is proposed for the interaction of two robots in synchronized operation with complex motion of an object. The inverse kinematic problem is solved for two manipulators connected by the object being manipulated. Formulas are derived for the controllable generalized coordinates in group control, with constraints corresponding to parallel manipulator operation.

Abstract The applicability of electrical discharge machining (EDM) in creating textured surfaces is investigated. Recommendations are made regarding the use of selective laser melting to create complex tool electrodes. The theoretical basis is established for the creation of textured working surfaces, so as to produce a hydrophobic material capable of oil storage, with consequent decrease in friction

Abstract Contact in the honing of cylindrical holes is simulated. Nonlinear behavior of the mean contact pressure and the transfer coefficient is observed. These factors depend on the applied force and the surface relief, as well as the materials used in the tool and workpiece.

Abstract The properties of composites based on expanded graphite and a steel base with structured macroscopic relief are studied: specifically, the wear resistance, frictional coefficient, and reduced wear. The structured macroscopic relief is produced by deformational cutting.

Abstract The transverse mechanical characteristics of PR-KKh30VS, Co29Cr8.5W, and Co30Cr12.5W cobalt alloys produced by laser surfacing are compared in tensile tests. Attention focuses on the tensile strength, the character of failure, and the sample hardness.

Abstract It is of interest to assess the life of high-speed taps in machining structural-steel workpieces. A general multiparametric formula is derived for the permissible wear. By that means, the tool life may be effectively utilized, and the metal removal in regrinding may be standardized.

Abstract The temperature is analyzed in the machining of a one-piece compressor impeller, by simulation. The results obtained by means of the proposed algorithm are presented.

Abstract A generalized system of relationships corresponding to different quality indices during machining of surfaces is developed. A general characteristic for assessing the surface quality of manufacturing products is derived.

Abstract The polishing of a lithium-niobate single crystal is considered. The influence of the pressure and relative speed in polishing on the productivity and the final quality of the crystal’s end surfaces is investigated. Formulas are derived for the total depth of the layer destroyed in finishing and the minimal time required for its removal.

Abstract A simplified monitoring head is proposed, and its kinematic accuracy is analyzed. The effectiveness of this head—that is, the monitoring precision—when monitoring manufacturing tolerances depends on the length of the probe.

Abstract The use of chromium carbides to harden surfaced metal that is subject to abrasive wear is considered. With correct hardening of the applied layer, carbide formation extends the working life.

Abstract A refined model is derived for the burnishing forces on hollow cylindrical workpieces when using a tool with regular microgeometry and metal-cladding lubricant. These conditions permit wear-free operation with Garkunov–Kragel’skii friction.

Abstract A gear-shift device based on rollers is proposed for a gearbox with composite gears and built-in clutches. For the sake of speed, the drive is an electric step motor with a combination of a screw pair and a wedge mechanism at the shaft. That increases the controllability of the clutch.

Abstract The influence of the density of the tool’s track grid (the raster cycloid) on the surface roughness of a cylindrical surface is studied experimentally. The resulting mathematical formulas permit calculation of the height of the surface irregularities with variation in the density of the track grid in the course of honing by abrasive bars of different grain size.

Abstract The use of Co30Cr12.5W cobalt-alloy powder in laser surfacing is considered. The characteristics of the powder are determined. In laser surfacing, both individual tracks and overlapping tracks are employed. The microstructure and microhardness of the samples are assessed.

Abstract Experimental data illustrate how wire electrical discharge machining (EDM) affects the surface roughness of titanium products obtained by powder-based laser surfacing. For samples of VT 20 titanium alloy corresponding to State Standard GOST 19807–91 and VT 20 alloy samples produced by powder-based laser surfacing, the difference in surface roughness is 15%, in fixed electrical discharge machining

Abstract A general design procedure for a production system is outlined, in accordance with IDEF0 notation. A generalized mathematical model is developed on the basis of standardized functional modules.

Abstract The influence of the pulse energy in electrical discharge machining (EDM) of deep holes in 40Х steel workpieces is studied. The factors considered are the change in steel microstructure within the machining zone and the change in dimensions, shape, and surface roughness of the hole under the action of the current pulses. The depth of the defective layer in finishing and precision machining

Abstract Design options for equipment used to hone high-precision holes in measuring equipment and fuel systems are outlined. The available equipment permits self-stabilization of the tool–workpiece system, with compensation of errors in their mutual position. The quality and precision of the holes are improved by flushing of the wear products from the machining zone.

Abstract Electrical discharge machining of VKU-29 polymer composite by means of continuous and perforated masking sheets is considered. The tool electrode consists of M1 copper. The unperforated mask results in the best surface quality, without defects or structural changes. In the electrical discharge machining of VKU-29 polymer composite using masks, there are no visible traces of torn layers or

The quenching of annealed Р6М5 high-speed steel by a constant-action ytterbium fiber laser (a Yb:YAG CW laser) is studied. The optimal conditions for laser quenching of Р6М5 high-speed steel are found to be as follows: laser-spot diameter 2 mm; speed 0.4 cm/s; and power density 10 kW/cm2. In those conditions, Р6М5 high-speed steel is quenched to hardness 58–60 HRC.

The adhesive strength of Co30Cr12.5W, PR-KKh30VS, and Co29Cr8.5W cobalt-alloy coatings applied by laser surfacing on a structural-steel substrate is assessed in comparative tests. The critical load, stress, and type of sample failure are determined. Recommendations are made for increasing the adhesive strength of the coatings.

A method is developed for determining the optimal electrical discharge machining (EDM) conditions of complex components made of steel with elevated high-temperature wear resistance, in the light of the physicomechanical properties of the workpiece. A multilevel system is developed for calculation of the electrical discharge machining conditions in such cases. This system identifies the parameters ensuring

The strength of 30N8G6M3FTB steel alloyed with boron nitride and carbide depends on the compounds Nb6C5, V6C5, NbC, Mo0.72Nb0.28B2, VB, Ti3N1.29, NbN, and NbVN2 formed in surfacing by means of powder-core wire. This material may be used in coating components operating with moderate wear.

The finishing of the parabolic surface of a hard-alloy punch by a diamond wheel with a multilayer composite electrolytic coating is considered. The cutting forces on an individual grain are calculated. Cutting conditions corresponding to long tool life and the required surface quality are identified.

Improvement in the vibroacoustic diagnostics of rotors is considered. Sensitive and reliable signs are identified by the analysis of the two-dimensional probability-distribution densities of vibrational amplitudes. That approach permits assessment of the nonlinearity of the dynamic model for a machine regarded as a vibrational system. Diagnostics of the plant compressor conlition illustrates, among

Abstract Existing drive transmissions are analyzed. A toothed belt transmission with a driven pulley that includes an elastic rubber bush is proposed. Formulas are presented for the kinematic nonuniformity of rotation of the driven pulley, its velocity, and its angular displacement as a result of bush deformation.

Abstract The creation of Russian supersonic passenger planes is considered. The development of promising airliners for no more than 20 passengers is discussed. A hybrid power unit consisting of turbojet and supersonic ramjet engines is proposed. The proposed hybrid system performs well both in ascent and descent and in cruising. This approach has undeniable economic and engineering benefits.

Abstract The shaping of a rectangular welded sheet assembly by pressurized gas is investigated by finite-element modeling. It is found that, in the formation of a cylindrical dome, the width of the assembly decreases at first and then, after reaching the shell diameter, begins to increase. In other words, the cylindrical shell is deformed practically without thinning.

Abstract A model permitting simulation of the magnetic field scattering of a current-bearing winding on a round ferromagnetic rod is developed. The model is verified experimentally.

Abstract The use of the following quality-control instruments in the machining of cylindrical liners at repair shops is considered: Shewhart charts (of moving-range and individual-measurement types) and histograms for analysis of the adjustment precision. A monitoring checklist has been developed for determining the losses due to all defect types. Interchangeability among groups for piston–liner assemblies

Abstract The strategy of import substitution adopted for airplane-engine manufacture in Russia has already shown benefits. In comparison with other branches of industry, the production of aircraft engines requires a special approach, because of its high technological content. The state of gas-turbine production for power generation and gas pumping is analyzed. Drawing on experience gained during the

Abstract The hardness of heat-resistant chromium alloy may be decreased by heat treatment. The influence of the hardness on the wear rate of alloy tools in turning is investigated.

Abstract The surface machining of corundum-ceramic components by free abrasive is discussed. The influence of the following factors on the final surface roughness is determined: the type of machining (tumbling or vibrational tumbling), the shape of the abrasive bodies, the presence or absence of machining fluid, the machining time, and the drum speed in tumbling. On that basis, recommendations are

Abstract The actual relative contact area of plane steel surfaces is investigated as a function of the rated pressure in dynamic contact loading. The actual contact area is found to be less in dynamic loading than in static loading.

Abstract The tool wear and microcrack formation in the machining of medium-carbon bearing steels are studied experimentally for the example of ШХ15-ШД and 75ХГСФ steels. Numerous features of the wear of polyhedral single-use inserts with a wear-resistant coating are noted. Different behavior is observed for the two types of bearing steel. To determine the roughness of the machined surface, its dependence

Abstract The straightening of low-rigidity cylindrical components by transverse rolling with smooth plates is considered. The influence of absolute reduction after straightening on the following parameters of the products is studied: the linearity and diametric precision of the product; and the microstructure, hardness, and hardened depth of the strengthened part.

Abstract Attention focuses on the production of the spherical front surface of a ball-end mill, close to the transition from the cylindrical section. Analysis of the possible interference of the grinding wheel and the mill permits recommendations for decreasing the errors. The shaping errors due to plane approximation of the curvilinear front surface are discussed.

Abstract The thermal processes in turning are investigated by electrical analogy. An equivalent electric circuit is proposed for the system consisting of the workpiece, cutting insert, holder, and lathe housing. The corresponding model, derived by means of Simulink Mathlab software, describes both steady and transient thermal processes. A numerical example illustrates the effectiveness of simulation

Abstract The relation between tool wear in metal turning and the reactive forces on the tool is studied experimentally. The experimental variation of the reactive forces observed experimentally during wear growth matches the sections of the wear curve: that is, stabilization of the forces is observed at first, but then the reactive forces increase sharply on approaching catastrophic wear. Extrapolation