bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication of Shapes with Overhang Using Micro-Boring Tools
Authors: Egashira Kai , Harada Kazuyuki , Yamaguchi Keishi , Ota Minoru
Published: September 2014

The boring of microholes has been carried out using micro-turning tools. There is a limitation, however, on machinable shapes using the tools employed therein, with the fabrication of shapes with an overhang being impossible. The fabrication of such shapes was therefore attempted in the present study using cemented tungsten carbide micro-boring tools processed by electrical discharge machining. Inner-grooving by turning was attempted in 0.15-mm-diameter holes, resulting in shapes with an overhang, such as a reverse-tapered hole. Furthermore, inner-grooving using tools moving in planetary motion was also attempted in 0.2-mm-diameter holes drilled in workpieces that were difficult to deal with by turning.
Development of an Advanced Machine Control System in Superfinishing the Automatic Determination of the Suitable Machining Time
Authors: Onishi Takashi , Ohashi Kazuhito , Higashi Kohei , Iguchi Takahiro , Yamashita Shingo , Isa Hajime , Tsukamoto Shinya
Published: September 2014

In superfinishing, a fine surface can be obtained by transiting the machining states from the cutting action to the finishing one. In this study, we propose an advanced machine control system in superfinishing. The superfinishing stone is retracted automatically when the proposed system detects improvement in the surface roughness of the workpiece. The suitable machining time is determined by monitoring the machining force ratio measured with a force sensor. With machining experiments, we confirm that the finished surface roughness can be controlled by adjusting the threshold value of the machining force ratio to retract the superfinishing stone during machining.
A Study on Fast Geometric Form Measurement of High Precision Balls
Authors: Lu Hui Zong , Wang Zhi Wei , Deng Qian Fa , Lv Bing Hai , Zhou Fen Fen , Yuan Ju Long
Published: September 2014

A dual probe non-contact ball roundness measurement method is presented in this paper. With two probes aligned in opposite directions, the direct measurement of diameter variation can be obtained. The relationships between diameter variation and out of roundness of a precision ball are discussed. Attempts of error separation using multiple measurements are carried out and the eccentricity of ball and spindle axis is measured. Measurement results indicated that other than the spindle radial run out, which is synchronous in nature, there also exists high frequency non-synchronous variations. Such non-synchronous errors can be effectively eliminated with the dual probe arrangement for diameter variation measurement. The measurement results showed that such set up is capable of measuring high precision balls for diameter variation and out of roundness with uncertainty of less than 10nm. Single measurement can be completed in 10 seconds with over 10,000 data points. Faster measurement is possible with improved air bearing spindle. The method is suitable for online application of precision ball diameter variation and out of roundness measurement.
Development and Practicality of a Scanning Point Autofocus Instrument for High Speed Areal Surface Texture Measurement
Authors: Miura Katsuhiro , Nose Atsuko , Suzuki Hirofumi , Okada Mutsumi
Published: September 2014

A point autofocus instrument (PAI) is widely used for the roughness and contour measurement of various precision processing surfaces, because it is capable of measuring a large area in high precision. The only disadvantage of PAI is to require a long measurement time. Its conventional index measurement stops the scanning stage in order to obtain each coordinate value of the fixed sampling pitch. Hence, it was necessary to develop a scanning point autofocus instrument (SPAI) which can obtain coordinate values while the scanning stage is moving. As an achievement of the development, the SPAI offers 26 times faster measurement speed than that of the index measurement with equivalent accuracy. The SPAI easily measures 3D surface texture and provides quantitative evaluations of the precision processing surfaces.
Numerical Investigations on the Grinding Forces in Ultrasonic Assisted Grinding of SiC Ceramics by Using SPH Method
Authors: Liang Zhi Qiang , Mi Zhao Yang , Wang Xi Bin , Zhou Tian Feng , Wu Yong Bo , Zhao Wen Xiang
Published: September 2014

In this study, the grinding force variation mechanism in ultrasonic assisted grinding (UAG) of SiC ceramic is investigated by simulation method using a single diamond abrasive grain scratching. In simulation, the workpiece is modeled by smoothed particle hydrodynamic (SPH) method while the abrasive grain is modeled by finite element method (FEM). To reliably predict the grinding forces in UAG, an analytical model of average undeformed chip thickness ha is established. Grinding forces under different grinding parameters, i.e., depth of cut, and different ultrasonic vibration amplitudes are calculated by setting average undeformed chip thickness haas scratching depth during SPH simulation process. The simulation results indicate that the normal force in UAG is reduced by about 20%, while the tangential force decreases up to 30% compared with those in conventional grinding (CG). The influences of grinding parameters and ultrasonic vibration on grinding forces will be investigated and the preliminary explanations will be presented.
High-Speed Capturing of Stress Distribution of Workpiece under Ultrasonically Assisted Cutting Condition
Authors: Isobe Hiromi , Hara Keisuke
Published: September 2014

This paper reports the stress distribution inside the workpiece under ultrasonic vibration cutting (UVC) condition. Many researchers have reported the improvement of tool wear, burr generation and surface integrity by reduction of time-averaged cutting force under UVC condition. However general dynamometers have an insufficient frequency band to observe the processing phenomena caused by UVC. In this paper, stress distribution inside the workpiece during UVC was observed by combining the flash light emission synchronized with ultrasonically vibrating cutting tool and the photoelastic method. Instantaneous stress distribution during UVC condition was observed. Because UVC induced an intermittent cutting condition, the stress distribution changed periodically and disappeared when the tool leaved from the workpiece. It was found that instantaneous maximum cutting force during UVC condition was smaller than quasi-static cutting force during conventional cutting when the cutting speed was less than 500 mm/min.
Curved Surfaces Forming of Sheet Material by Laser Irradiation
Authors: Kishida Keisuke , Aoyama Hideki , Mastushita Naohisa , Ushimaru Akihiko
Published: September 2014

Laser forming is a technology which can form sheet material such as steel and plastic by irradiating a laser beam on the surfaces of material. In the forming, it does not need costly dies and molds, and forming degrees of freedom are high. However, since the forming mechanisms are complex, complete forming technology for practical use has not been developed. The objectives of this paper are to explain phenomena of laser forming by experiments and FEM analysis and to develop a forming method of curved surfaces by laser forming. The phenomena are explained by the temperature change, stress change, and plastic strain change at a laser irradiation point which was obtained by FEM analysis. Line energy is proposed for explanation of laser forming phenomena to classify the forming mechanisms, and a method is proposed in order to form curved surfaces of sheet material by irradiating a laser beam on maximum and minimum curvature lines. The effectiveness of the method was verified by a basic experiment.
Development of Ultrasonic Lapping Equipment for Small Holes Finishing
Authors: Liang Jin , Kang Ren Ke , Ma Fu Jian , Liu Jin Ting , Yu Yue Bin
Published: September 2014

Lapping is widely applied to hole surface finishing. However, for small holes of high hardness material, low efficiency and unstable hole surface quality of traditional lapping cannot be ignored. In this paper, the ultrasonic transducer and horn–tool were designed by the analytical method and the finite element method (FEM). An equipment of ultrasonic lapping for small holes was developed. Vibration performance tests of developed equipment were conducted by using microscope and laser displacement sensor. The result showed that the amplitude of ultrasonic lapping equipment can meet manufacturing demand. The machining performance of the developed ultrasonic lapping equipment was also investigated by comparing the surface quality and material removal rate with traditional lapping. The result showed that the higher material removal rate and better hole surface quality can be obtained by ultrasonic lapping.
A Preliminary Study of Surface Integrity and Wheel Wear in the Grinding of Multilayered Thin Film Structures
Authors: Kang Cheng Wei , Hao Bing Jun , Huang Han
Published: September 2014

This study aimed to investigate the effect of grinding conditions, including depth of cut and grinding direction, on the material removal and surface finish of multilayered thin film structures. It was found that the increase in depth of cut improved the material removal rate, but worsened the ground surface finish. The grinding perpendicular to the thin films caused less damage and produced better surface than that parallel to the films. The characteristics of wheel wear were also studied. Grit pull-out and micro-fracture should be attributed to the wheel wear.
Design and Solder Process Optimization in MID Technology for High Power Applications
Authors: Syed-Khaja Aarief , Franke Jörg
Published: September 2014

Molded interconnect device (MID) technology is a key enabling technology with growing markets in automotive, communications, consumer electronics through integration with lighting and sensor technologies. The MID technology is yet to be explored for high temperature applications in automotive or consumer lighting. One of the hindering factors for such implementation in the serial production and time to market is the improper electronic and thermal packaging of the light emitting diodes (LEDs) on the MID substrates. This paper addresses the optimization of mold design, surface metallization and soldering process for the effective thermal management of the high-power LED systems. By using a simulation model, the thermal distribution and the resultant decrease in temperatures for varying forward electrical currents in high-power LEDs by design optimization is demonstrated. In addition, the optimization of solder process with respect to solder profile in context of vacuum vapor-phase soldering for void-free solder connections is discussed.
Electrical Functionalization of Thermoplastics by Combining Plasmadust Coating and Aerosol Jet Printing
Authors: Schramm René , Hörber Johannes , Dold Christoph , Franke Jörg
Published: September 2014

Additive structuring and metallization technologies like Plasmadust or Aerosol Jet printing offer many advantages for future MID applications. Both digital writing technologies enable a highly flexible design of the circuit pattern and are capable of coating 3D substrates. Currently, Aerosol Jet printing is used to generate patterns with accurate and detailed features, and line widths of 100 μm. Plasmadust provides variable coating thicknesses up to 200 μm combined with a high process speed. Hence, a combination of both technologies appears to be advantageous for a broad range of MID applications. In this paper an initial study on the interconnection of plasmadust and Aerosol Jet generated conductive structures on thermoplastic substrate materials is presented. In this context different printing strategies and process variations are evaluated.
Orientation Dependence of Cycle Stability of Superelasticity Response in Quenched and Aged Ferromagnetic Co35Ni35Al30 Single Crystal
Authors: Eftifeeva A.S. , Panchenko E.Yu. , Chumlyakov Yuriy
Published: September 2014

Using Co35Ni35Al30 (at.%) single crystals the effects of crystals axis orientation and ageing at 673 K for 0.5 h in free state on superelasticity responses in compression are investigated. Ageing of these single crystals is found to result in strengthening of the high-temperature В2 phase and L10 martensite, twofold increasing of temperature interval of SE response and weakening of the orientation dependence and improving the cycle stability of superelasticity response. In [011]- and [123]-oriented single crystals the values of the stress hysteresis decrease a nearly threefold as compared to the quenched state. The combination of high-strength [001] crystal axis orientation and precipitation of coherent nanoscale particles leads to the best stability of SE response in aged Co35Ni35Al30 single crystals.
Role of Micro- and Nanofillers in Abrasive Wear of Composites Based on Ultra-High Molecular Weight Polyethylene
Authors: Panin Sergey , Kornienko Ludmila , Thuc Nguyen Xuan , Ivanova Larisa R. , Shilko Sergey V.
Published: September 2014

The abrasive wear of pure UHMWPE as well as one filled with nanoand microparticles (fibers) were investigated. It was found that abrasive wear resistance of microcomposites (containing AlO(OH) and Al2O3 microparticles) can grow up by 16-18 times in comparison with pure UHMWPE depending on the strength and size of the filler as well as abrasive grit. Nanofillers (AlO(OH) and carbon nanofibers (CNF) as well as SiO2 and Cu nanoparticles) as opposed to microfillers can improve abrasive wear resistance of UHMWPE in a significantly less degree (up to 50 %). Abrasive wear resistance of nanocomposites weakly depends on the type of filler and is defined by the polymeric matrix (permolecular) and counter-face abrasive grit. The comparative analysis of the wear mechanisms of UHMWPE based micro-and nanocomposites under abrasive wear (fixed abrasive particles) and dry sliding friction is carried out.
Sintering of NiO/YSZ Anode Layers for Metal-Supported Solid Oxide Fuel Cell
Authors: Solovyev Andrey A. , Ionov Igor V. , Kovalchuk Anastasya N. , Kirdyashkin Aleksandr I. , Maznoy A.S. , Kitler V.D.
Published: September 2014

The construction of a metal-supported fuel cell has been recently generating a growing interest among the designers of solid oxide fuel cells. The present work is aimed at solving the problem related to high-temperature sintering of fuel cell NiO/YSZ anode on the porous metal substrate functioning both as a supporting structure and a reliable current collector. Hence, its irreversible oxidation during high-temperature sintering should be avoided. NiO/YSZ layers were applied on porous metal samples by a screen-printing technique and sintered in reducing and inert atmospheres, as well as in vacuum. The obtained layers were studied by means of scanning electron microscopy and X-ray phase analysis. It was shown that a temperature of 1000°С does not ensure a substantial sintering of Ni and YSZ granules in a reducing atmosphere. Under the sintering temperature above 1230°С in an inert atmosphere and vacuum, the nickel oxide dissociation and its massive agglomeration are observed. The conditions of NiO/YSZ layer vacuum sintering were experimentally determined which provide a high-grade sintering of nickel cermet granules without Ni agglomeration, disturbance of homogeneity in the formed anode layer, and the metal substrate oxidation.
Study of Tungsten and Molybdenum Nanopowders Interaction with Sulphur in SHS Conditions and Synthesized Product Properties
Authors: Irtegov Yuriy , An Vladimir
Published: September 2014

X-ray and transmission electron microscopy results of initial tungsten and molybdenum nanopowders produced by electrical explosion of wire and used in metal sulfides synthesis is presented. Sulphur excess effect on metal nanopowders combustion with elementary sulphur and phase composition of products is studied. Tungsten and molybdenum disulfides obtained by self-propagating high-temperature synthesis under argon pressure 3 MPa and sulphur excess 15 wt. % in initial mixture are crystallized in layered aggregates with layer thickness 20-30 nm.
Development of New Ni-Al Porous Alloys for Metal-Supported Solid Oxide Fuel Cells
Authors: Kirdyashkin Alexander , Kitler V.D. , Maznoy A.S. , Solov’ev A.A. , Kovalchuk A.N. , Ionov Igor V.
Published: September 2014

The technique of synthesis of Ni+16mass%Al open cell type porous intermetallic materials that can be treated in inert or regenerative atmospheres at temperature up to 1600 K without changing their functional properties has been developed. Materials with Ni3Al + NiAl phase composition, porosity of 42 %, sizes of transport pores up to 10 μm, sizes of core elements equal to 40 μm, and specific surface of open porosity of 90 mm-1 have been produced. It is demonstrated that after complete oxidation of the given materials, the NiO-NiAl2O4 composite is formed, whose reduction in hydrogen flux results in the formation of Ni-NiAl2O4 cermet; the shape of the porous material in the course of oxidation/reduction does not change.
Decomposition and Preconcentration Methods for the Determination of Pt, Pd, Re in Mineral Raw Materials
Authors: Oskina Yulia A. , Pakrieva Ekaterina , Ustinova Elvira M. , Kryazhov Andrey
Published: September 2014

Nowadays the actual problem of geochemistry is a deep and complex processing of mineral raw materials. Data on the quantitative content of precious and rare metals in various types of ores and rocks are necessary. It stimulates the development and improvement of chemical analytical methods for determination of these elements. Such methods are not applicable without sample preparation stage. Preparation of samples for analysis is the decomposition and preconcentration of rare and precious metals from matrix of mineral raw materials. The sample preparation schemes of platinum, palladium and rhenium are described in this paper.
Electrochemical Response of Gold Nanoparticles at a Graphite Electrode
Authors: Perevezentseva Daria , Gorchakov E.V.
Published: September 2014

The electrochemical activity of gold nanoparticles at graphite electrodes by the method of cyclic voltammetry is studied. In this article the nature of the supporting electrolyte, modification time of graphite electrode by gold nanoparticles and the potential range on the value of the “inverse” cathodic peak are investigated. The “inverse” cathodic peak of gold nanoparticles formed in the reaction mixture HAuCl4:Na3C6H5O7:NaBH4=1:1:4 is observed on the cathodic branch of cyclic voltamperegram at Ec = 0.05 V at graphite electrode. The mechanism of stepwise electrochemical oxidation and reduction of the phase structure of gold on the surface of the graphite electrode in 0.1 M NaOH is offered. The “inverse” cathodic peak of gold nanoparticles on the cathodic branch of cyclic voltammogram at graphite electrode is caused by oxidation of Au2O to Au2O3.
Features of Processing of Ceramic Materials by an Electromagnetic Field
Authors: Klishin Andrey , Kovancev Alexander , Rudnev Stanislav , Zakutaev Alexander , Vereshchagin Vladimir
Published: September 2014

The issues of structural changes produced in ceramic materials on the basis of Al2O3 and ZrO2(Y2O3) during thermomagnetic processing (B=0.02–1 T) are considered. The contribution of the electromagnetic field to the linear shrinkage of processed ceramic samples has been estimated to be 1–6%. The possibility of using the thermomagnetic processing method for obtaining the disperse and homogeneous structure has been shown. The technological modes of processing under the electromagnetic field are suggested, facilitating self-cleaning and perfecting the crystalline structures of Al2O3 and ZrO2(Y2O3), including annealing in the temperature range of 800–1200 °C within 8–12 hours.
One-Pot Synthesis of Gelatinized Maize Starch-Graft-Polyacrylic Acid Films
Authors: Edeleva Mariya , Grekova Alexandra , Khlestkin Vadim
Published: September 2014

In this article we provide results on the preparation of starch-based block copolymer with polyacrylic acid by radical polymerization. Starch was pregelatinized and then reacted with acrylic acid in the presence of radical polymerization initiator. Resulting mixture was used to prepare cast-films. Structure of the polymer films was investigated by gel filtration chromatography, FTIR and DCS analysis. It was found that structure of the films represents starch-graft-polyacrylic acid dispersed in a starch matrix. Results of DCS and FTIR suggested that polyacrylic acid acts as additional plasticizer for starch films.
Processes of Ultra- and Nanofiltration for Cleaning Solutions from Iron Colloid Substances
Authors: Machekhina Ksenia , Shiyan Ludmila N.
Published: September 2014

The application of NF90 membrane was shown to be the most effective for the removal of silicon and iron ions and organic substances from natural water. In this case, the membrane retention capacity amounts to ~ 86.0 % for silicon ions. The application of GR81PP and GR95PP membranes was shown as the most effective for the removal of iron ions and organic substances from natural water. In this case, the membrane retention capacity amounts to ~ 86.0 % for organic substances and 99.8% for iron ions. Therefore, the processes of ultra- nanofiltration can be used as a post-treatment step for groundwater of Western Siberia.
Suppressing the Hydrogen Sulfide and Sulfur Dioxide Emission from Sulfur-Bituminous Concrete
Authors: Gladkikh Vitaliy A. , Korolev Evgeniy Valerjevich
Published: September 2014

There are numerous advantages of building materials based on sulfur-bituminous binder. Using the sulfur-bituminous concretes in road construction leads to improved quality of pavements. In particular, there is an increase of resistance to rutting when extending the bituminous concretes with sulfur. The well-known difficulty limiting the widespread practical use of the sulfur-bituminous concretes is the emission of toxic gases – hydrogen sulfide and sulfur dioxide – which are formed during the manufacture and installation of sulfur-bituminous concrete. The present paper is devoted to the said problem. The survey of processes occurring in sulfur-bituminous mixtures is carried out. This allowed us to select most prospective suppressors for toxic gases emitted during the production and laying of sulfur-bituminous concrete. Series of laboratory tests are made to proof our choice. The results of tests confirm that oxides of amphoteric metals neutralizers are effective suppressors for hydrogen sulfide and sulfur dioxide, while carbon only slightly reduces the emissions. The emission is primarily depends on temperature and water content. Therefore, we recommend not to exceed 145 °C during the production and laying. Components for asphalt must be dehydrated, and sulfur must be degassed. If these requirements are met, than production process of sulfur-bituminous concrete will meet the safety requirements.
Synthesis of β-SiAlON Porous Ceramics by Filtrational Combustion of Reactive Foams in Nitrogen Flow
Authors: Maznoy A.S. , Kirdyashkin Alexander , Gabbasov Ramil
Published: September 2014

Process of synthesis of porous ceramics via organization of the filtrational mode of combustion synthesis in reactive samples preliminary structured by the method of foaming of slurry is investigated. The Al + SiO2 + N2 system is investigated; the target product of synthesis is β-SiAlON. It is demonstrated that high-porosity ceramic materials inheriting initial structure of the porous space of reactive systems can be fabricated in the filtrational mode of combustion synthesis. This has allowed us to vary the pore space parameters in wide ranges. The β-SiAlON based ceramic materials with total porosity from 40 to 75%, sizes of core elements 250–750 μm, sizes of porous channels 10–200 μm, and specific surface 4–15 mm-1 have been fabricated. It is demonstrated that combustion in reactive gas flow considerably intensifies the process of combustion synthesis.
Performance Evaluation of Plasma Sulphate Disposal Lignin
Authors: Karengin A.G. , Karengin A.A. , Novoselov I.Yu. , Piunova K.G.
Published: September 2014

This article presents the review and analysis of the literature on methods of utilization of sulphate lignin. It is the product obtained after the processing of cellulose. As a result of the calculations the optimal compositions of the water, organic materials with mechanical impurities with adiabatic combustion temperature about 1200 K to spontaneous combustion were determined. With help of obtained results experimental studies in plasma catalytic reactor were carried out and the also reactor’s operation was optimized. The results can be used to build industrial plants on the basis of plasma catalytic reactor for utilization sulphate lignin.
Sol-Gel Synthesis of Chelate Containing Materials for Gas Chromatography
Authors: Gavrilenko Mikhail A. , Slizhov Yurii G. , Faustova Zhanna V. , Kasymova Tatiana A. , Gavrilenko Nataliya A.
Published: September 2014

The adsorption properties of mesoporous chelate containing sorbents which were prepared in two phases with europium and copper acetylacetonate complexes and PEG-115 as surfactant, were evaluated by column experiments.The adsorption properties of mesoporous silica with chelate complexes for some organic compounds were evaluated by gas chromatography. The best separation was achieved for europium acetylacetonate. From specific retention volumes measured at various temperatures the thermodynamic parameters of separation is discussed. Mutual separation of oxygen containing substances could also be demonstrated.
Numerical Comparison of Gas Flows through Plane Porous Heat-Evolutional Object with Axisymmetric one when Object's Outlet is Partially Closed
Authors: Lutsenko Nickolay A.
Published: September 2014

Using numerical experiment the gas flow in the gravity field through a plane porous object with heat sources inside and partial closure of the object's outlet has been investigated and compared with axisymmetric case. The influence of partial closure of the object's outlet on the cooling process of the plane porous objects with a non-uniform distribution of heat sources has been analyzed by means of computational experiment. It has been revealed that effect of the top cover on a cooling process of the plane porous objects is qualitatively the same as in the axisymmetric objects, but quantitative differences are significant.
Influence of Surfactants on the Structure and Wear Resistance of Copper Alloyed Hypereutectoid Steel
Authors: Stepanova Natalia , Razumakov Alexey , Lozhkina Elena , Zhil'tsov Ivan , Kuznetsov Viktor
Published: September 2014

Influence of modifying with silicocalcium (SiCa) on the structure and friction properties of the hypereutectoid steel alloyed with 8.85 wt. % of Cu was studied. SiCa modifying of the copper alloyed hypereutectoid steel, led to the formation of the vermicular graphite distributed in the indendritic space instead of cementite. Coefficient of friction reduction and increased wear resistance were marked in the copper alloyed hypereutectoid steel due to the presence of graphite and cupric inclusions in the steel structure. The wear resistance of the graphitized hypereutectoid steel alloyed with 8.85 wt. % of Cu was almost 5 times higher compared to the wear resistance of bronze BrA9J3L and 75% higher compared to the wear resistance of antifriction cast iron AChS-1.
Numerical Research on the Influence of Autonomous Power Plant Condenser Design on Two-Phase Stream Parameters
Authors: Vysokomornaya Olga V. , Kuznetsov Genii V. , Strizhak Pavel A.
Published: September 2014

In this paper, the mathematical model is developed for the numerical research on the condenser tubes’ relative position influence on the output temperature of a two-phase stream. The limit distance between the condenser tubes which provides the required output vapor parameters is established.
Residual Meso Stresses in Multilevel Crystal Plasticity Models
Authors: Volegov Pavel S. , Trusov Peter V. , Gribov Dmitry S.
Published: September 2014

The problems related to the construction of multi-level mathematical models of inelastic deformation of crystalline materials based on crystal plasticity are considered. The example of the two-level model for description the severe plastic deformation of fcc polycrystals is discussed. The issues relating to the description of hardening and rotations of crystal lattices of the grains are discussed. The focus is on the formation of residual mesostresses in individual grains in the case of polycrystalline stress relief with a representative volume in general.
Some Aspects of Computer Approaches to Simulation of Bimodal Sphere Packing in Material Engineering
Authors: Burtseva Larysa , Pestryakov Alexey , Romero Rainier , Valdez Benjamin , Petranovskii Vitalii
Published: September 2014

This paper summarize idealized theoretical studies of bicomponent particle packing parameters, affecting the phase and pore structure of obtained materials. Such a kind of analysis can be used both in theoretical consideration of material engineering problems and in chemical industry. The effects of key variables on the relationship between packing fraction and particle size were re-examined for general application. Potential applications of these results include synthesis of nanopaterials, adsorbents, catalyst carriers and packing for chromatographic columns. Directions for future research are suggested.
Viscoelastoplastic Model of FCC Monocrystals Deformation: Identification of Parameters
Authors: Gribov Dmitry S. , Volegov Pavel S.
Published: September 2014

This article considers the description of elastoviscoplastic deformation for FCC crystallite. The deformation model for crystallite is necessary for building the model of a polycrystal. The elastoviscoplastic model is used to consider the crystalline structure using crystalline directions and also using the continuum mechanics approach – averaging by the representative macrovolume. FCC crystalline plastic deformations are considered as a slip of dislocations on slipping systems. А pure fcc cuprum is used аs a material. The algorithm for description of the proposed measures of the stress-strain state is considered, and hardening laws are analyzed. The problem of stochastic optimization of inelastic crystalline deformation is solved. Hardening modules and initial critical stresses are identified and accepted stochastically. The squared difference between the computational and experimental stress intensity for several points have been used as the target function. To solve the optimizing problem, the authors have used the min-max model considering the solution with the least favorable conditions for controlling vector. Nelder-Mead method (numerical method for direct search) is applied to solve the optimization problem. We have provided a description and analysis of the numerical results, recommendations for choosing the values of the identified parameters.
Modeling the Dynamics of 3-D Elastic Anisotropic Solids Using Boundary Element Method
Authors: Igumnov Leonid A. , Markov Ivan , Rataushko Yan Yu.
Published: September 2014

The numerical modeling problem is solved using a direct formulation of the boundary element method. The integral Laplace transform is used, as well as time-step methods of its numerical inversion. Matrices of fundamental and singular solutions are computed with the help of a combined direct-interpolation approach. The computational results obtained are compared with the results of other authors.
Evaluation of Gravitational Force Effect on Balancing Processes in Liquid-Type Autobalancing Devices
Authors: Pashkov E.N. , Martyushev Nikita V. , Masson Igor A.
Published: September 2014

The article examines the effect of gravitational force on the operation of a liquid-type autobalancing device. Results of the mathematical analysis and experiments are presented. When performing a hydrodynamic calculation of the rotation speed the effects of gravitational and centrifugal forces as well as the effect of the liquid’s force friction against the housing are considered. The analysis results show that the speed at which the gravitational force in an autobalancing device may be negligible is greatly dependent upon the radius and coefficient of gravitation. Moreover, the less the gravitational coefficient and the greater the radius, the greater the angular velocity of an autobalancer. As a result of the conducted investigation, the speeds evaluating the possibility of using liquids as balancers at low rotation speeds are provided in this paper.
Self-Similar Reflection of Longitudinal Shock Wave from Free Boundary in Elastic Medium
Authors: Potyanikhin Dmitrii A. , Dudko Olga V.
Published: September 2014

Self-similar solution of two-dimensional problem of interaction between a plane longitudinal shock wave and free boundary of elastic half-space is considered. It is suggested that the intensity of this wave is constant. Feasible combinations of wave surfaces which may be generated in elastic medium as a result of such interaction are investigated. Choosing of unique physically admissible mode of deformation propagation from among mathematically possible wave patterns is related to shockwave evolutionary condition and the second law of thermodynamics.
Novel Techniques of Ceramic Shell Molds Production with Lost-Wax Method
Authors: Sapchenko Igor G. , Zhilin Sergey G. , Komarov Oleg N.
Published: September 2014

In this paper we propose novel techniques of ceramic shell mold production with lost-wax method of cast as well as technological methods aimed at fracture strength improvement. The distinguishing characteristic of application of these molds is the possibility to use them without buckling agent resulting in decrease of prime cost in casting.
On the Classification of Three-Link Mechanisms
Authors: Popugaev Maxim G. , Dvornikov Leonid T.
Published: September 2014

In this article we consider three-links mechanism. We try to classify them according to L.T. Dvornikov’s classification of mechanism, which subdivide them into families, types, classes, orders and also into assurovi and notassurovi.
Rational Designing Two-Stage Anvil Block of Impact Mechanisms
Authors: Zhukov I.A. , Molchanov V.V.
Published: September 2014

In the article the solution of the problem of heightening of efficiency of impact systems for the score of selection of rational shapes anvil blocks is reduced. Shape execution of anvil block in the form of two steps is offered - impact and cylindrical piston, which length steal up by "golden section" rule. Results of a finding of shapes of the impact impulses generated at direct blow on rods two-stage anvil blocks are reduced and analyzed.
The Analysis of Shale Thermal Destruction Paths under Electrophysical Treatment
Authors: Ivanov Alexei , Lopatin Vladimir V. , Martemyanov Sergey M. , Bukharkin Andrey A. , Koryashov Ilia A.
Published: September 2014

The possible ways of shale destruction under electrophysical treatment were discussed. The products destruction were analyzed by GC-MS, DTA-TG and elemental analysis. The pyrolysis products formation was shown.
The Reactive Deposition of TiOx Thin Films
Authors: Sidelev Dmitrii V , Yurjev Yuriy N.
Published: September 2014

The article reports on the aspects of reactive deposition ultra-thin TiOx films (50 nm) by means of dual magnetron system with mirror and closed magnetic field (B field) configurations. The hysteresis effect of electrical discharge characteristics and oxygen partial pressure P(O2) are presented. The dual magnetron with closed B field configuration has less hysteresis peculiarities and transits back to metallic deposition mode at higher O2 flow rate (Q). The deposition rates don’t depend on B field configuration and correlate with changing of P(O2) and discharge voltage. The refractive spectra and energy of band gap, which are measured by UV-visible spectrophotometry and ellipsometry (λ=632.8 nm) methods, have strong dependence on Q(O2).
Spark Plasma Sintering of Mechanically Activated Ni and Al Powders
Authors: Shevtsova Lilia I. , Korchagin Michail A. , Thömmes Alexander , Mali Vyacheslav I. , Anisimov Alexander G. , Nagavkin Sergey Yu.
Published: September 2014

In this paper structure and mechanical properties of Ni3Al intermetallic compound was studied. The materials was fabricated according to different schemes, which combined mechanical alloying of Ni and Al powders, self-propagating high temperature synthesis (SHS) and spark plasma sintering (SPS). Relative density of all sintered samples was ~ 97 %. Microhardness of the sintered materials ranged from 6100 to 6300 MPa. SPS of 86.71 % wt. Ni and 13.29 % wt. Ni powder at 1100 °C led to formation of material with the highest level of tensile strength equal to 400 MPa.
The Structural Particularities of Multilayered Metal-Intermetallic Composites Fabricated by the Spark Plasma Sintering Technology
Authors: Lazurenko Daria B. , Mali Vyacheslav I. , Anisimov Alexander G. , Yartsev Pavel S. , Lagereva Daria I. , Shevtsova Lilia I.
Published: September 2014

Particularities of the multilayered “Ti – Al3Ti” composites structure formation were investigated. Spark plasma sintering of Ti and Al plates in cylindrical molds at the temperature of 830 оС and pressure of 3 kN during 5 minutes was found to be the most efficient technology of formation of materials with intermetallic layers. The regime described above allows fabricating material with high-quality intermetallic layers and with microhardness level up to 3800 MPa.
Efficiency of Balancing by Liquid-Type Automatic Balancing Devices
Authors: Pashkov E.N. , Martyushev Nikita V. , Ponomarev Andrey V.
Published: September 2014

The article focuses on modelling the behaviour of a liquid-type automatic balancing device. To perform mathematical research the rotor model is used that contains a ring functioning as a vessel coupled to the rigid shaft being rotatable on bearings. Data on the influence of various factors on balancing accuracy are presented. The obtained modeling results indicate that the vibration amplitude at supercritical frequencies will decrease proportionally to the increase in the parameters of a liquid autobalancer. The performed calculation also reveals that the more the parameters of a liquid autobalancing device, the higher the efficiency of balancing. Provided the condition of the liquid sufficiency in the ring is satisfied, the independence of the rotor vibration amplitude from the mass of the liquid in the vessel is achieved. Critical rotor speed does not depend on the volume of the liquid in the ring if the condition of its sufficiency is met.
Engineering Analysis of Structural Variants of Corrugated Aperture in the Environment MSC.Patran/MSC.Marc
Authors: Koltsov Vladimir , Popova Elizaveta , Rakitskaya Valentina
Published: September 2014

This article provides the results of the study of the strain-stress state of two corrugated shell structures. Geometric modeling was conducted in “Autodesk Inventor” system. Corrugated shell structures were studied with the help of engineering analysis systems MSC.Patran and MSC.Marc. As a result of the study an optimal type of corrugated shell structure was chosen.
Molecular Dynamic Simulation of Carbon Nanostructures Formation
Authors: Tatarnikov Denis A. , Godovykh Aleksey V.
Published: September 2014

This paper is devoted to the study of stable structures of various carbon nanomaterials using molecular dynamic simulation, study of their properties and characteristics, as well as search for possible later use in nanoelectronics and nanomechanics. We develop programs for computation of the system of atoms at every step and visualization of that data, also we research of thermodynamic properties and conditions of formation of different carbon nanostructures, try to predict existence of new materials. Nowadays we have two separate programs: one for computation and one for visualization. We continue to collect statistical data, investigate behavior of the system under different conditions.
Roll Design Method of Single–Stage Profile Ring Rolling Based on Modified UVDET
Authors: Kim Byung Min , Lee Kyung Hun
Published: September 2014

The aim of this study is to suggest the die design method for single-profile ring rolling in the production of a large scale welding neck flange, based on the modified uniform volume distribution element technique (UVDET). UVDET is presented as the ratio of volume change of ring blanks to that of undeformed rings per unit height. A welding neck flange has only one–side contour without a symmetry plane and the highly different volume distribution. To manufacture this type of ring, the blank preforming is recommended before a single–stage profile ring rolling process. FE simulations were performed to test the validity of proposed die design method, under Forge software environment.
Study of the Effect of Cyclic Strain Reversal on the Interactions between SRX and PPT in the Microalloyed Austenite during Hot Rolling Process
Authors: Muszka Krzysztof , Lisiecka-Graca Paulina , Simm Thomas , Palmiere Eric J.
Published: September 2014

In the present work cyclic torsion test was used to simulate hot plate rolling process in order to study the effect of strain reversal on non-recrystallisation temperature using unalloyed and microalloyed austenite model alloys. It was found that the amount of strain reversal directly influences both static recrystallisation and strain-induced precipitation process significantly delaying their kinetics. The proper assessment of the interactions between strain reversal and microstructure evolution plays a crucial role during hot rolling process - as continuous changes in the deformation mode (strain reversal) affect the level of redundant strain (in the areas near the surface of the stock) and lead to strain inhomogeneity across the plate thickness. This complex strain path introduces microstructural inhomogeneity and makes its predictions very difficult. Proper understanding of the effects of strain reversal on microstructure evolution in the austenite will help to optimise the hot rolling process.
Influence of the Punch Penetration Depth in Half Punching on the Cut Edge after Shaving
Authors: Masahiro Sasada , Yusuke Kamiichi , Takayuki Kikuchi
Published: September 2014

Shaving is one of the precision shearing methods used to remove the rollover and fractured surface. The rollover and fractured surface formed in the punching stage are removed by shaving. It is expected that the rollover will be reduced when half punching with a negative clearance is carried out in the punching stage. In this study, the influence of the punch penetration depth in the punching stage on the cut edge after shaving was investigated. The results of this study clarified the followings: When the punch penetration depth in the punching stage with negative clearance is large, the sheared surface obtained by shaving after half punching with negative clearance is larger than that obtained by conventional punching. The sheared surface obtained by shaving after half punching with negative clearance increased with increasing the punch penetration depth in the punching stage with a negative clearance. The rollover produced by shaving after half punching with negative clearance is smaller than that produced by conventional shaving. In addition, the chip produced by shaving after half punching is connected to the sheet material under the punch. From the observed deformation of the chip produced in the shaving stage after half punching with negative clearance, the mechanism of shaving after half punching is considered to be cutting followed by shearing.
A Study on the Hinge Bracket Forming by Thickening of a Sheet
Authors: Lee Hyun Kyu , Kim Jong Ho , Kim Jong Bong
Published: September 2014

A hinge bracket is usually produced by bending of a sheet panel or welding of a hollow bar into a sheet panel. The hinge bracket that is made by bending or welding, however, does not have sufficient durability due to the stress concentration on the bended region or low corrosion resistance of the welded region. In order to make hinge bracket with high durability, a bracket is needed to be produced by forming process. In this study, a thickening process of a sheet panel for the hinge bracket is investigated. The maximum thickening limit in one stage was determined for various aspect ratios of specimen. Finally, the optimum multi-stage forming process was designed for hinge bracket forming and the process was verified by numerical experiment.
Investigation of the Mandrel’s Stress States and Wear Conditions during Tube Hot Extrusion of IN690 Superalloy
Authors: Yang Jing , Zhou Qing Jun , Sun Chao Yang , Liu Dong
Published: September 2014

A 2D axi-symmetric finite element model for tube hot extrusion process has been established by consideration of the billet transfer, glass lubrication, constitutive equation of IN690 superalloy and modified Archard wear model. The influence of extrusion process parameters on the stress state and wear conditions of the mandrel surface has been investigated. The results show that under the optimal extrusion process parameters of the extrusion speed of 250 mm/s, the friction factor of 0.05 and the billet preheating temperature of 1250 ̊C, the mandrel can be reused 200 times when it is fixed and 500 times when it moves with the ram.
Adjustment of Blank Holding Force Distribution Utilizing a Multi-Point Die Support System
Authors: Ohashi Takahiro , Tong Wan
Published: September 2014

In this study, the authors employ a multi-point die-support structure to hold the upper die for deep drawings in order to adjust the distribution of the blank holding force (BHF) so as to eliminate wrinkles. The developed multi-point support structure has 12 support cells (support units) between the upper die and the outer slide of a double-action press; the cells are metal cylinders working as springs. The support unit has a ball contact at the interface with the upper die, and the interface freely rotates and slides horizontally. The support unit has strain gauges on the side surface, and the bearing load at each unit can be determined, as well as the elastic deformation. The bearing load distribution is observed through a trial blow, and then the support units are manually relocated to better distribute the supporting points to create the appropriate BHF distribution. To demonstrate the efficiency of the suggested structure, the authors perform deep drawing with off-centered setting of a blank to create wrinkles intentionally. They then employ the multi-point die-support system, relocate the support units, and eliminate wrinkles.
Novel Wear Testing Apparatus to Investigate the Reciprocating Sliding Wear in Sheet Metal Forming at Elevated Temperatures
Authors: Ghiotti Andrea , Bruschi Stefania , Sgarabotto Francesco , Medea Francesco
Published: September 2014

Hot stamping has gained increasing importance in the last years due to the introduction of High Strength Steels (HSS) to improve the strength-to-mass ratio of stamped components. Despite the advantages in terms of load decrease, springback reduction and increased formability, the elevated temperatures the tools are subjected to may determine severe thermal mechanical cycling, increased oxidation and wear, which influence the tools service life and the quality of the produced parts. In addition, the frictional behaviour is also changing with temperature, thus affecting the performance of the forming operation itself. In this paper a novel experimental apparatus suitable for reciprocating sliding wear tests at elevated temperatures is presented. It consists of a linear sliding guideway connected to an electrical actuator and equipped with a heating plate to heat metal sheets. A solid frame embeds a screw device used to apply normal load. Thermocouples placed both on the plate and on sheet sample are used to control temperature during the test. The machine is also equipped with two load cells to record the normal and the tamgential loads. The 22MnB5 high strength steel was chosen as reference material for the machine testing. The results showed the capability of the new equipment and the good stability of the mechanical and thermal condition during testing.