Manufacture Of Blanks Research Articles

Формування сучасної конструкції маримби як темброво-акустичної системи

The purpose of the work is to consider the history of the formation of the modern construction of the marimba as a timbre-acoustic system. Methodology. The work used the following research methods: induction, deduction, comparative analysis, spectral analysis of sound in order to establish its acoustic structure. The scientific novelty of the research is that it presents a new perspective on the evolution of the marimba design, due to the improvement of its acoustic capabilities and technical parameters of the instrument, which have a significant impact on the performing process. Conclusions. The evolution of the marimba spans a period of several thousand years. The path traversed from a completely primitive percussion instrument to a high-tech design was associated with the search and development of structural details that would reveal new acoustic and timbre “sides” of the instrument, as well as expand the horizons of technical possibilities for performers. The active phase of the process of creating new samples of marimba developed in several directions and falls on the beginning of the 20th century. As a result, a number of original, sometimes exotic designs appear, which, for one reason or another, have not been established in performing practice. Significant advances in the industrial production of marimba have been achieved thanks to the inventions of American engineers, who have had a significant impact on a number of factors related to the improvement of acoustic properties and technical parameters of instrument design. Experiments with wood species for the manufacture of blanks for marimba bars have shown that Honduran rosewood and paduk are used as the main material for their production. The alternative was a synthetic material – kelon. Marimba bars emit rather quiet sounds, the vibrations of which quickly fade away. In this regard, they must be reinforced with an additional structural element. For this purpose, modern designs of marimba use both resonators in the form of a tube, closed at one end, and a device based on the principle of “Helmholtz resonator”.

Application of the Polymeric Material RIMAMID for Production of Machine Parts

Modern polymeric materials have properties that, in some respects, exceed the properties of traditionally used materials (steel, aluminum and titanium alloys, wood). The uniqueness of the Rimamide polymer material is that it is possible to pre-design the material in such a way as to give the product from it the properties necessary for a particular application.The production of blanks and the use of Rimamide material for the manufacture of sliding and rolling bearings, bushings for wheels and rollers, pulleys, blocks, brackets, wheel hubs, gears, sprockets, gears and worm wheels and other parts to reduce weight, noise and vibrations. The characteristics of the material, examples of the manufacture of blanks, the advantages and disadvantages of the RIMAMID material for the manufacture of machine parts, prospects for use in mechanical engineering are shown.Due to their properties, they can be used in almost all industries. For example, modern aviation and space technology is characterized by the intensive use of new materials, technologies, and promising designs based on them. When using RIMAMID material using antifriction components (molybdenum sulfide, graphite, etc.), the friction coefficient is significantly reduced and the friction units can be operated without lubrication.The main advantages of this material is a low coefficient of friction for steel, which provides a 3-4-fold increase in the service life of parts in the friction units, as well as low weight, high strength, good machinability on metal cutting machines, resistance to aggressive environments, and environmental safety.

Analysis of the Open Die Forging Process of the AZ91 Magnesium Alloy.

The paper presents the results of numerical modelling of the forging process of magnesium alloy ingots on a hydraulic press with the use of flat and shaped anvils. The use of shaped (rhombic-trapezoid) anvils will affect the uniform distribution of temperature and strain intensity in the entire volume of the forging, causing a number of forging passes, which in consequence will reduce the costs of the blank manufacturing process. However, higher values of the strain intensity were obtained during the deformation of the material in flat anvils. The purpose of the research was to propose assumptions for forging technology of producing a blank from AZ91 alloy with the use of flat and shaped anvils. Numerical examination for AZ91 magnesium alloy was carried out using the Forge®NxT commercial software. The rheological properties of the investigated alloy were determined on the basis of uniaxial compression tests carried out in the Gleeble 3800 metallurgical simulation system. The numerical analysis of the process of forging AZ91 alloy ingots on a press was conducted in the temperature range of 200–400 °C and at several forging passes.

Specifics of Producing Disk Blanks for Gas-Turbine Engines using Granules of Super Heat-Resistant Nickel Alloys

The paper discusses the specifics of chemical composition, hot isostatic pressing (HIP), and heat treatment of granulated heat-resistant nickel alloys characterized by high long-term strength at 750°C. The results are presented which were obtained by studying EP975-type alloy during manufacturing of large-sized disk blanks for aircraft gas-turbine engines (GTE) using the technology based on metallurgy of granules. Changes in the microstructure after long-term testing at high temperature were evaluated. The phase stability of the material was confirmed.

Designing a duplicate model of the GTE turbine blade casting process

The work describes the results of developing a duplicate model of the gas turbine engine blade casting process. The work was based on the development of the digital “furnace-flask-filler-mould-metal-stopper” process system considering the geometrical, structural and thermophysical specifications of the turbine blade casting process. The industrial approbation of the developed process under the experimental production conditions exemplified by the manufacture of the GTE turbine moving blades demonstrated a 3- to 4-fold decrease in time of the blade blank manufacturing cycle due to the virtual multi-iteration optimization of the process.

Energy Saving and Low-Cost-Oriented Design Processes of Blank’s Dimensions Based on Multi-Objective Optimization Model

The blank’s dimensions are an important focus of blank design as they largely determine the energy consumption and cost of manufacturing and further processing the blank. To achieve energy saving and low cost during the optimization of blank dimensions design, we established energy consumption and cost objectives in the manufacturing and further processing of blanks by optimizing the parameters. As objectives, we selected the blank’s production and further processing parameters as optimization variables to minimize energy consumption and cost, then set up a multi-objective optimization model. The optimal blank dimension was back calculated using the parameters of the minimum processing energy consumption and minimum cost state, and the model was optimized using the non-dominated genetic algorithm-II (NSGA-II). The effect of designing blank dimension in saving energy and costs is obvious compared with the existing methods.

Manufacture of Joints in Rocket-Engine Housings

The manufacture of blanks for polymer-composite joints by winding and subsequent installation on the primary housing of a solid-fuel rocket engine is described. A device for winding and installing such components is considered.

A new approach to deformation control of aeronautical monolithic components of aluminum alloy plates based on stress inverse and stress evaluation

In the high-speed machining process of aeronautical monolithic component, the release of residual stresses is a crucial factor of machining deformations with the material removal of 7075 aluminum alloy thick plates. Therefore, the investigation on the evolution mechanism of machining deformation with residual stress release is crucial for machining quality control. It is vital to achieving a high-efficiency and precise machining process. In this work, the bending deformation theory is employed to formalize the mechanical model of machining deformation, which is influenced by the removal of materials. The finite element method is used to calculate the unit deformations by producing the unit stresses in each layer of the aluminum alloy thick plate. The unit force method is established so that the mechanical model of machining deformation can decompose to be multiple of deformation factor with residual stress. Further, by considering the self-equilibrium of residual stresses, the specification model of residual stresses is proposed based on the fact that the machining requirement represents the control limit of machining deformation. By introducing a new unit variable, the sandwich theorem is employed to convert the specification model into the linear homogeneous inequalities. Therefore, the pivot transformation method is suggested to solve the residual stresses in the specification model. Finally, by representing an arbitrary variable as a difference between two non-negative variables, the linear programming method is proposed to judge whether the measured blank initial residual stress is a solution of stress specification. This can evaluate machining deformation within the machining requirement. The active evaluation of residual stresses, which is deduced from the passive analysis of machining deformations by unit force method and pivot transformation, can provide the proper stress specification for the upper of the machining process. Obviously, the stress specification plays a very important role in the bridge between the blank manufacturing and the machining process.

Production of Hollow Alloy Blanks with Shape Memory Effect

Abstract—The manufacture of blanks from alloys based on titanium nickelide with shape memory is proposed by means of reverse extrusion with subsequent thermomechanical treatment and crimping. The alloy plasticity is analyzed as a function of the temperature and strain rate. The shaping of such blanks is investigated.

Hot Axial Rotary Forging of Flanges Standard EN 1092

The paper considers the technology of manufacturing flange parts using local methods of metal forming. Various technologies of manufacturing of ring blanks for the subsequent rotary forging of flanges are offered and investigated. On the basis of computer simulation, the main dimensions of the workpiece have been chosen, providing the best forming parts and the parameters of the technology mode. The results of experimental studies have shown that this technology is possible to manufacture flanges according to EN 1092 using the process of axial rotary forging with cylindrical rolls. The use of local methods of deformation of metals allows expanding the possibilities of technological processes at lower power equipment.

Improving the accuracy of electric mechanisms for the manufacture of blanks of agricultural objects

The principles of increasing the precision characteristics of an agricultural electric drive are presented in this article. There are achieved by analyzing the requirements for the electric drive by the operating body. The scientific work has a relationship between the parameters of the quality of rolling the blanks for agricultural facilities and the precision parameters of the electric drive in terms of overshoot parameters and absolute positioning accuracy. It is shown that this dependence is non-linear in the position electric drive and depends more on the size of the overshoot and a significantly smaller ratio from absolute accuracy. The permissible overshoot value depends on the absolute accuracy and has range from 5 to 10%. The largest value of the overshoot is achieved with absolute positioning accuracy with an error not exceeding 2%. The obtained values of the control parameters can be successfully applied in the design of the position agricultural electric drive. So, if you provide sufficient positioning accuracy with an error not exceeding 2%, which is achieved by the use of position sensors with a resolution of at least 10 000 pulses per revolution, the modeling electric drive in the position loop can be adjusted with an allowable overshoot of 10%, and therefore, increased system performance while maintaining quality control indicators.

Multi-criteria optimization by the «ideal point» method of raw material composition for composite blank manufacturing

The paper provides the results of an experimental study into the properties of compressed and sintered compacts of the following powders: VT-22 high-strength titanium alloy manufactured by plasma spraying of industrial titanium production waste, PTM-1 grade titanium manufactured by the hydrate-calcium method, and PV-N70Yu30 nickel-aluminum alloy. It was shown that charge composition selection for composite blank manufacturing is connected with the need to ensure optimization of several competing target functions. The relative density and strength of compacts under axial compression after sintering, as well as charge cost were chosen as optimization criteria. The problem was set and the method was proposed to select an optimal charge composition providing the necessary values of density, strength, as well as relatively low cost of products. The problem of multi-criteria optimization was solved based on the ≪ideal point≫ method. The results of calculations were compared with the previously obtained solutions of the problem under consideration using the Pareto method, linear programming, and generalized criterion. It was shown that different methods of multi-criteria optimization lead to significantly different results. In this case, the ≪ideal point≫ method gives the minimum discrepancy between the experimental and model values of the optimization criteria selected. The results of this study were used to create an expert system for the multi-criteria optimization of composite manufacturing processes. The charge composition obtained by the «ideal point» method was transferred to an industrial plant where an axially symmetric part was manufactured. The ultimate strength and relative density of the manufactured part material were in conformity with the predicted values.

Formation of 04Cr18Ni9 steel structure and properties during additive manufacturing of blanks

This work presents results of studying specifics of structure and properties of 04Cr18Ni9 steel formation in additive processes, namely, in СМТ (Сold Меtal Тransfer) additive manufacturing and plasma additive manufacturing at reverse polarity current and consumable electrode plasma additive manufacturing (Plasma MIG). The main problem that arises when additive technologies are applied is to ensure that properties of laminates are no lower than those produced using traditional methods. Typical defects of laminates produced by additive manufacturing are increased porosity, nonmetallic inclusions, reduced plasticity, and for high-alloy steels, loss of special properties. The work includes a comparison in structure and mechanical characteristics of materials obtained by CMT additive manufacturing, plasma additive manufacturing at reverse polarity current, and consumable electrode plasma additive manufacturing. It is established that mechanical characteristics of samples made of 04Cr18Ni9 steel obtained by additive manufacturing are no lower than those of steel of similar composition in the deformed state.

Deconsolidation of C/PEEK blanks: on the role of prepreg, blank manufacturing method and conditioning

The combination of rapid automated lay-up and stamp forming has great potential for rapid manufacturing of lightweight load carrying components of thermoplastic composites. However, deconsolidation during blank heating is currently limiting the applicability of rapid lay-up blanks. This experimental work investigates the origin of deconsolidation in blanks produced by advanced fiber placement (AFP) versus traditional press consolidation. The influence of moisture on deconsolidation is investigated through deconsolidation experiments in a convection oven, as well as thermo-mechanical and residual gas analyses. The experiments revealed that thermal expansion of dissolved moisture is the main deconsolidation mechanism for press-consolidated blanks, but not for AFP blanks, which are suggested to deconsolidate mainly due to the release of frozen-in fiber stresses present in the used prepreg.

Manufacturing of tailor-rolled blanks with thickness variations in both the longitudinal and latitudinal directions

A tailor-rolled blank is a semi-finished part that can be used to produce stamping parts with continuous thickness variations. This study investigates a cold manufacturing process to fabricate a TRB with variable thickness variations in both the longitudinal and latitudinal directions. The effect of the rolling process on the characteristics of the transition zone and the deformation behaviors of the blanks were investigated using various processing conditions. The dimensional variations at the transition zones were analyzed based on the cross-sectional thickness profiles of the formed blanks. The results show that manufacturing such a TRB requires an extra process to reduce dimensional instabilities caused by superimposed transition zones in both directions. To manufacture sound blanks with acceptable dimensions, this study proposes a trial method that uses blanks with circular and square holes instead of solid blank.

Development and Implementation of the Casting of Rods Made of Refractory Cast Alloys

The problems of the production of a so-called casting rod blank made of a refractory casting alloy in the vacuum induction furnaces of AO Metallurgical Plant Electrostal are considered. A unique technology of casting and subsequent treatment of as-cast rod blanks made of refractory alloys is developed, tested, and optimized. As a result of the developed and performed measures for the production of metal products in the Consarc furnace, the ingot-to-product yield increases by 15% as compared to metal casting in an ISV-1.0 furnace. As a result, we have widened the range of cast alloy grades and are going to cast metals for the manufacture of blanks of other sizes and ranges of alloy an steel grades.

Effects of Y-TZP blank manufacturing control and addition of TiO2 nanotubes on structural reliability of dental materials

Titanium dioxide (TiO2) nanotubes have been applied to enhance the mechanical and biological properties of dental materials. Yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) have been increasingly used in dentistry as a substructure for crowns and fixed partial prostheses. Aside from its optimal clinical results, Y-TZP is prone to failures due to microstructure-related defects introduced in the manufacturing process that may lower its structural and clinical reliability. The purpose of this study was to evaluate the role of the manufacturing process of blanks as well as their original composition modification by addition of TiO2 nanotubes (0%, 1%, 2% and 5% in volume) while controlling all manufacturing steps. Materials were subjected to a biaxial flexural strength test, a fractographic qualitative analysis by scanning electron microscopy (SEM), a microstructure evaluation in field emission-SEM and X-ray diffraction. Values of flexural strength were subjected to ANOVA, Tukey (α = 0.05) and Weibull statistics. Grain size values were subjected to Kruskal-Wallis and Dunn tests (α = 0.05). Highlights of the results include that for experimental Y-TZP added 2% vol TiO2 nanotube ceramics presented flexural strength values at 577MPa and Weibull modulus (m) at 8.1. The addition of TiO2 nanotubes in different blends influenced experimental Y-TZP properties, leading to lower flexural strength, although they presented higher m than the commercial Y-TZP. Nanotubes also led to bigger grain sizes, more pores and a slight increase in the monoclinic phase, influencing the microstructure of Y-TZP. Y-TZP blank manufacturing control as well as addition of TiO2 nanotubes led to higher m values and, hence, greater structural reliability.

Laser beam shaping for modification of materials with ferritic-martensitic structure

A identify conditions of laser heating for warm forming of materials with a ferritic-martensitic structure was performed. The laser source was a fiber laser with maximum output power of 1500 W. The beam was transformed to an elliptical ring with use a plano-convex lens and axicon. Study of the microstructure allowed revealing fibrous structure of metal, formed during the manufacture of blanks by rolling. Place of plastic deformation is characterized by a local decrease the thickness profile. To eliminate of this defect, is advisable to use the diffractive optical elements, which redistribute the power density of a laser beam.

Новое в прессовании многощеточных заготовок, заготовок щеток и неармированных щеток

The article is devoted to new developments in the field of brush production of electric machines. A number of different types of brushes, depending on their design and purpose, are given. Each type of brush has its own range of parameters such as density, resistivity, surface hardness, mechanical strength and contact friction during brush operation. New technologies and a way of manufacturing of multi-brush blanks in the form of blocks are described, and also new designs of molds for production of these products are presented. New developments have allowed to increase the density of compacts and, as a result, to increase the mechanical and physical properties of finished brushes

Influence of hot ring rolling on uniform deformation of High-speed rail bearing ring

Abstract Bearing ring blanks of the high-speed rail bearings, machine tool spindle bearings and wind power bearings have been manufactured through the ring rolling technology. Yet, the inhomogeneous deformation of bearing ring in hot ring rolling remains unclear. In this work, the numerical model of hot ring forming for the high-speed rail bearing ring (HSRBR) is established, which is validated by the experimental method. Then, several parameters, such as the altitude h0, and h0s are selected to study their effects on the homogeneous deformation of HSRBR. Further, the uniform deformation of HSRBR is improved according to the numerical results. These results provide valuable guidelines for the design and manufacture of ring rolling mills and HSRBR blanks.