scholarly journals Reduced Statistical Representation of Crystallographic Textures Based on Symmetry-Invariant Clustering of Lattice Orientations

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 336
Author(s):  
Kirill V. Ostapovich ◽  
Peter V. Trusov
Keyword(s):  
Rotational Symmetry ◽  
Physical And Mechanical Properties ◽  
Orientation Distribution ◽  
Effective Characteristics ◽  
Crystalline Lattice ◽  
Reduced Form ◽  
Modern Material ◽  
Statistical Representation ◽  
Operational Characteristics ◽  
Macro Scale

As proven in numerous experimental and theoretical studies, physical and mechanical properties of materials are determined by their internal structure. In the particular case of polycrystalline metals and alloys, an important role is given to the orientation distributions of crystalline lattices, or, in other words, crystallographic textures. Physically reasonable models of texture formation are highly demanded in modern Material Science and Engineering since they can provide an efficient tool for designing polycrystalline products with improved operational characteristics. Models of interest can be obtained on the basis of statistical formulations of multilevel approaches and crystal elasto–visco–plasticity theories (in particular, Taylor–Bishop–Hill models and their various modifications are appropriate here). In such a framework, a representative volume element of a polycrystal is numerically implemented as a finite aggregate of crystallites (grains or subgrains) with a homogenized response at the macro-scale. Quantitative texture analysis of this aggregate requires estimating statistically stable features of the orientation distribution. The present paper introduces a clustering-based approach for executing this task with regard to preferred orientations. The proposed procedure operates with a weighted sample of orientations representing the aggregate and divides it into clusters, i.e., disjoint subsets of close elements. The closeness criterion is supposed to be defined with the help of a special pseudometric distance, which takes rotational symmetry of the crystalline lattice into account. A specific illustrative example is provided for better understanding the developed procedure. The texture in the clustered aggregate can be described reductively in terms of effective characteristics of distinguished clusters. Several possible reduced-form representations are considered and investigated from the viewpoint of aggregating elastic properties in application to some numerically simulated textures.

Macroscopic 2D Design of Micro/Nano Grain Architectures by Laser Interference Metallurgy

2007 ◽  
Vol 1059 ◽  
Author(s):  
Frank Muecklich ◽  
Carsten Gachot ◽  
Rodolphe Catrin ◽  
Ulrich Schmid ◽  
Andrés Lasagni
Keyword(s):  
Electron Backscatter Diffraction ◽  
New Technology ◽  
Orientation Distribution ◽  
Crystalline Lattice ◽  
Recrystallization Process ◽  
Laser Interference ◽  
Nano Structures ◽  
Grain Formation ◽  
Dimensional Finite Element ◽  
Backscatter Diffraction

ABSTRACTTailoring of micro/nano structures and surface functionalization are key goals in surface processing of materials. A new technology for a unique geometric precise 2D micro/nano design of grain architectures is presented. By means of super lateral grain growth crystalline lattice patterns such as line-, dot- and cross-like patterns were generated. The grain dimensions may be selected between a few nanometers and about 10 micrometers. The phase and grain formation was characterized by Electron Backscatter Diffraction with regard to orientation distribution and texture formation. Furthermore, dynamic aspects of this laser induced recrystallization process are studied, such as the heat transport in the films, comparing the vertical with the lateral solidification velocities by two-dimensional finite element method (FEM) simulations. Finally, the mechanical properties of the tailored thin films have been determined using nanoindentation experiments.

scholarly journals Operational characteristics of four metering systems for agricultural fertilizers and amendments

2009 ◽  
Vol 29 (4) ◽  
pp. 605-613 ◽  
Author(s):  
Jesus H. Camacho-Tamayo ◽  
Angela M. Barbosa ◽  
Nancy M. Pérez ◽  
Fabio R. Leiva ◽  
Gonzalo A. Rodríguez
Keyword(s):  
Physical And Mechanical Properties ◽  
Crop Productivity ◽  
Operational Parameters ◽  
Commercial Fertilizer ◽  
Rotating Speed ◽  
Feed Screw ◽  
Operational Characteristics ◽  
Speed Range ◽  
Unloading Rate ◽  
Lime Powder

The use of fertilizers and solid amendments in agriculture generates special interest for their effect on crop productivity, as well as for their environmental impact. The efficient use of these products demands knowing their physical and mechanical properties, the storing conditions effect and the operational characteristics of the metering systems used in the fertilizing equipment. In this context, the present study was developed with the purpose of evaluating the operational characteristics of different fertilizing metering systems and to determine the adequate metering system-product operational parameters, using powder lime, powder gypsum, granular 10-30-10 (N-P-K), and granular urea. Operational differences were established among four types of commercial fertilizer metering systems, including wire auger, star-shaped feed wheel, feed screw and ridged traction wheel. The study found that the unloading rate depends directly on the fertilizer metering system's rotating speed and is affected by particle size, repose angle, bulk density and moisture content of the applied product. The wire auger and star-shaped feed wheel metering systems were adequate for the distribution of powder products and the feed screw for granulated fertilizers. Furthermore, theoretical and experimental characteristic equations were established, defining curves for calibration and handling of the products plus the rotating speed range in which a better distributing behavior was achieved.

scholarly journals Optimization of Ingredients upon Development of the Protective Polymeric Composite Coatings for the River and Sea Transport

2021 ◽  
Vol 23 (2) ◽  
pp. B89-B96
Author(s):  
Andriy Buketov ◽  
Serhii Yakushchenko ◽  
Abdellah Menou ◽  
Oleh Bezbakh ◽  
Roman Vrublevskyi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Epoxy Composite ◽  
Composite Coatings ◽  
Physical And Mechanical Properties ◽  
Polymeric Composite ◽  
Epoxy Oligomer ◽  
Mathematical Planning ◽  
Sea Transport ◽  
Operational Characteristics ◽  
Critical Content

It is proved that in order to increase the operational characteristics of parts of the river and sea transport, including their physical and mechanical properties, it is advisable to use the protective polymeric composite coatings. The effect of fillers on the flexural stresses of the developed epoxy composite was analyzed. The critical content of components was determined by the method of mathematical planning of the experiment: the synthesized powder mixture - 0.05 pts.wt., discrete fibers - 0.10 to 0.15 pts.wt. per 100 pts.wt. of epoxy oligomer ED-20. Introduction of such ingredients into the epoxy binder allows to increase the flexural stresses to σ f=77.4…78.6 MPa. The obtained results allow to create materials with improved values of physical and mechanical properties.

Study of Micro Ultrasonic Machining of CFRP/Ti Stacks

2017 ◽  
Author(s):  
Abhishek Sonate ◽  
Dheeraj Vepuri ◽  
Sagil James
Keyword(s):  
Three Dimensional ◽  
Weight Ratio ◽  
Tool Material ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Groove Depth ◽  
Machining Process ◽  
Shear Stresses ◽  
Ultrasonic Machining ◽  
Macro Scale

Carbon fiber reinforced plastic (CFRP) composite is one of the most sought after material owing to its superior physical and mechanical properties such as high-durability and high strength-to-weight ratio. CFRP composites are often used by stacking up with titanium (Ti) to form multi-layered material stacks for applications involving extreme mechanical loads. However, machining of CFRP/Ti multi-stacks is quite complex and challenging task since both materials are difficult-to-machine materials and show completely different machinability properties. The challenge is further escalated when there is a need to machine CFRP/Ti stacks at micron level. Several problems arise during the machining process due to the non-homogeneous structure, anisotropic and abrasive properties of composite. Traditional methods of micromachining the CFRP/Ti stacks results in several issues including high cutting force and torque and high tool wear, composite delamination, large groove depth in composite, and poor surface quality. Ultrasonic machining (USM) process has been successfully used to machine titanium, CFRP and CFRP/Ti stack at macro scale. Micro Ultrasonic machining is a downsized version of macro ultrasonic machining process that is developed to machine hard and brittle materials. This research explores the possibility of using Micro USM process to conduct micromachining of CFRP/Ti multi stacks. The effect of various process parameters including abrasive grit size, tool material and type on the material removal process is studied. The study found that micro ultrasonic machining process is capable of successfully micromachining CFRP/Ti stacks with zero CFRP delamination, minimal variation in CFRP and Ti hole sizes and longer tool life. Further, a three-dimensional finite element simulation study is performed on micro ultrasonic machining of CFRP/Ti stacks. The simulation results revealed that the workpiece is not subject to any significant normal stresses during the machining process, while variations in shear stresses is seen on the inside surfaces of the machined cavities.

scholarly journals EFFECT OF NANODIAMONDS ON OPERATIONAL CHARACTERISTICS OF FILLED COMPOSITE MATERIALS

2021 ◽  
Vol 64 (5) ◽  
pp. 57-62
Author(s):  
Tatyana V. Burdikova ◽  
Sergey S. Ivshin ◽  
Alina A. Ivshina ◽  
Lyubov A. Zenitova
Keyword(s):  
Functional Groups ◽  
Chemical Interaction ◽  
Physical And Mechanical Properties ◽  
Temperature Stability ◽  
Diamond Powder ◽  
Polymer Composition ◽  
Carbon Powder ◽  
Operational Characteristics ◽  
Strength And Stiffness ◽  
Destructive Processes

The paper presents the results of a study evaluating the effect of the addition of nanosized detonation diamond of the NA-SP brand on the characteristics of a filled polymer composition based on SKU PFL-100 prepolymer manufactured by Kazan Synthetic Rubber Plant JSC cured by 4,4'-methylene-bis-orthochloraniline. The scale of heterogeneity of the carbon powder was estimated. It is shown that the studied additive allows you to create a fairly dense and developed structure in a dispersion medium. The discussion of interfacial interaction at the nanodiamond – polyurethane interface is carried out, as well as the influence of the carbon nature of the filler particles. A possible chemical interaction between the functional groups of the prepolymer, hardener and particles of the studied additives is shown. The results of the experimental evaluation show that the combination of chemistry features (the presence of functional groups) and the mechanics of nanodiamond powder affects both the physical and mechanical properties of the filled polyurethane composition and its thermal stability. It was found that the introduction of up to 1% detonation diamond allows to increase the strength and stiffness of the polymer by approximately 2 times. As a result of the approximation of the experimental data, quadratic dependences of the physical and mechanical characteristics of the filled polyurethane system on the content of nanoscale diamonds in the range 0 - 1% (mass.) were obtained. The results of thermogravimetric analysis show that the introduction of 1% (mass.) detonation diamond powder can increase the temperature of destructive processes by about 20 °С. Anomalies in the dynamics of the process of dissociation of filled polyurethane are noted. It has been suggested that the introduction of detonation diamond leads to the initiation of secondary synthesis reactions with the formation of allophate and biuret groups with low temperature stability.

scholarly journals MODIFICATION OF COMPOSITE MIXTURES FOR MANUFACTURING SHIP CABLEWARE MATERIALS

2017 ◽  
Vol 12 (6) ◽  
pp. 91-97
Author(s):  
K. V. Raev ◽  
N. V. Chernousova
Keyword(s):  
Oxygen Index ◽  
Operating Temperature ◽  
Fire Hazard ◽  
Operating Time ◽  
Physical And Mechanical Properties ◽  
Polymeric Composite ◽  
Polymer Composition ◽  
Aggressive Environment ◽  
Operational Characteristics ◽  
Composite Mixture

The purpose of this work was to develop a modified polymeric composite mixture for the manufacture of the outer shell of a ship's cable operating under conditions of aggressive environment and increased fire hazard. The performed research resulted in the analysis of the basic polymeric composite mixtures. A complex of the most important technical and operational characteristics of the cable shell was formed. These characteristics are wear resistance, oil resistance and fire safety. On the basis of these assumptions a new polymer composition based on chloropolyethylene TYRIN CM 3630E with an increased oxygen index and improved physical and mechanical properties was developed. Modification of the mixture was carried out by increasing the mass fraction of flame-retardant additives and adding stabilizers to the mixture. Thanks to a balanced combination of technical and operational properties the use of the developed compound will increase the cable service life and operating time and will reduce the overall weight of the cable by using conductors of a smaller cross-section at a higher operating temperature.

scholarly journals Dark-field X-ray microscopy for multiscale structural characterization

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
H. Simons ◽  
A. King ◽  
W. Ludwig ◽  
C. Detlefs ◽  
W. Pantleon ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Structural Evolution ◽  
Physical And Mechanical Properties ◽  
Dark Field ◽  
Crystalline Materials ◽  
X Ray ◽  
Microscopy Technique ◽  
Three Dimensional Mapping ◽  
Macro Scale ◽  
Annealing Study

Abstract Many physical and mechanical properties of crystalline materials depend strongly on their internal structure, which is typically organized into grains and domains on several length scales. Here we present dark-field X-ray microscopy; a non-destructive microscopy technique for the three-dimensional mapping of orientations and stresses on lengths scales from 100 nm to 1 mm within embedded sampling volumes. The technique, which allows ‘zooming’ in and out in both direct and angular space, is demonstrated by an annealing study of plastically deformed aluminium. Facilitating the direct study of the interactions between crystalline elements is a key step towards the formulation and validation of multiscale models that account for the entire heterogeneity of a material. Furthermore, dark-field X-ray microscopy is well suited to applied topics, where the structural evolution of internal nanoscale elements (for example, positioned at interfaces) is crucial to the performance and lifetime of macro-scale devices and components thereof.

scholarly journals Finite Element Modelling for Tensile Behaviour of Thermally Bonded Nonwoven Fabric

2015 ◽  
Vol 15 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Xiaoping Gao ◽  
Liping Wang
Keyword(s):  
Finite Element ◽  
Cell Model ◽  
Orientation Distribution ◽  
Nonwoven Fabric ◽  
Tensile Behaviour ◽  
Fe Model ◽  
Machine Direction ◽  
Nonwoven Fabrics ◽  
Shear Property ◽  
Macro Scale

Abstract A nonwoven fabric has been widely used in geotextile engineering in recent years; its tensile strength is an important behaviour. Since the fibre distributions in nonwoven fabrics are random and discontinuous, the unit-cell model of a nonwoven fabric cannot be developed to simulate its tensile behaviour. This article presents our research on using finite element method (FEM) to study the tensile behaviour of a nonwoven fabric in macro-scale based on the classical laminate composite theory. The laminate orientation was considered with orientation distribution function of fibres, which has been obtained by analysing the data acquired from scanning electron microscopy with Hough Transform. The FE model of a nonwoven fabric was developed using ABAQUS software; the required engineering constants of a nonwoven fabric were obtained from experimental data. Finally, the nonwoven specimens were stretched along with machine direction and cross direction. The experimental stress-strain curves were compared with the results of FE simulations. The approximate agreement proves the validity of an FE model, which could be used to precisely simulate the stress relaxation, strain creep, bending and shear property of a nonwoven fabric.

scholarly journals CHANGE IN THE PROPERTIES OF ASPHALT CONCRETE WHEN USING HYDROPHOBIZED MINERAL POWDER

2020 ◽  
pp. 17-23
Author(s):  
V. Yadykina ◽  
E. Kuznetsova ◽  
M. Lebedev
Keyword(s):  
Asphalt Concrete ◽  
Water Saturation ◽  
Physical And Mechanical Properties ◽  
The Road ◽  
Operational Characteristics ◽  
Effect Of Treatment ◽  
Mineral Powder ◽  
Positive Effect

One of the main factors is the structure of asphalt concrete. The most important structural component in asphalt concrete is mineral powder, the quality of which depends on the technical and operational characteristics of the road surface. Different methods of processing mineral materials are used to improve the performance of asphalt concrete in Russia and abroad. In most cases, mechanical activation with organic substances is used during the grinding process. The article presents the results of research on the effect of treatment of mineral powder with the preparation GF-1 on its characteristics and on changes in the physical and mechanical properties of asphalt concrete, as well as on indicators for long-term water saturation. It is shown that as a result of modification, the mineral powder becomes hydrophobic, which has a positive effect on the physical and mechanical characteristics of asphalt concrete with its use. It is found that hydrophobization of mineral powder significantly reduces water saturation and swelling; increases water resistance during long-term water saturation (up to 90 days) of asphalt concrete samples. As a result of hydrophobization, the temperature sensitivity of asphalt concrete increases significantly. Therefore, the composite will work reliably in a wider temperature range.

Two-Scale Thermo-Crystal Plasticity Finite Element Analysis of Dynamic-Recrystallization Texture Evolution

2016 ◽  
Author(s):  
Yuhei Ueda ◽  
Yu Goto ◽  
Toshihiko Yamaguchi ◽  
Yoshihiro Tomita ◽  
Yusuke Morita ◽  
...  
Keyword(s):  
Finite Element ◽  
Dynamic Recrystallization ◽  
Heat Generation ◽  
Texture Evolution ◽  
Plastic Anisotropy ◽  
Shear Bands ◽  
Orientation Distribution ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
Macro Scale

In order to predict dynamic recrystallization (DRX) texture evolution during the forming processes of aluminum alloy, we propose a hypothesis to predict DRX evolution and develop a comprehensive computational tool for the thermal process metallurgy simulation. It consists of the two-scale finite element method based on the thermo-coupled elasto-crystalline plasticity analysis and the dynamic-explicit finite element procedure. It can predict the heat generation and diffusion, and plastic anisotropy at the macro-scale, and the crystal texture evolution including DRX due to the plastic deformation and heat generation at the micro-scale. The computationally evaluated texture evolution, which includes DRX texture, under the severe compression at high temperature is compared against the experimental results of pole figures and orientation distribution function (ODF) analyses. The results predict the evolution of the cube component which is observed in the experiments. Therefore, our proposed method is approved to have a potential predicting DRX texture evolution. Furthermore, we clarify the effect of DRX texture on the onset of such instabilities as necking, surface instability and shear bands which are closely related to the formability or failure of the materials.

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