Articoli di riviste: "Microstructure and crystal texture characterization"

1

Zhang, Kai, Knut Marthinsen, Bjørn Holmedal, Jesper Friis, Tanja Pettersen e Antonio Segatori. "Characterization and Modelling of the Microstructure and Texture Evolution in AlMgSi-Extrusions". Materials Science Forum 879 (novembre 2016): 1239–44. http://dx.doi.org/10.4028/www.scientific.net/msf.879.1239.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The properties and surface appearance of aluminium extrusion are critically dependent on the microstructure and texture of the extruded profiles, and the requirements with respect to these aspects may vary with applications. Moreover it is often a challenge to produce extrusions with a consistent and homogenous grain structure and texture along as well as through the cross section of the profiles. It is thus vital to understand and be able to predict (model) how different microstructures and textures are formed and how they evolve during and after extrusion. In the present work a model framework has been implemented which includes a FEM model to account for the strain, strain rate and temperature along a set of particle paths during extrusion. From these the deformation texture and grain structure are calculated with an appropriate deformation texture model and a sub-structure evolution model, respectively. The sub-structure model have in the present work been coupled to a crystal plasticity model to provide an orientation dependent subgrain size and dislocation density during deformation which provides the driving force for the post-extrusion recovery and possible recrystallization behaviour. The post-extrusion microstructure and texture evolution is calculated with a recovery and recrystallization model, which is accompanied by a recrystallization texture model. The framework and its constituent models and their interplay are presented, and some preliminary results when applying this modelling framework to Al-Mg-Si extrusions are presented and discussed in view of corresponding experimental results.

2

Rahmayeni, Syukri Arief, Yeni Stiadi e Herlin Oktavani. "PEMBUATAN DAN KARAKTERISASI NANOKOMPOSIT MFe2O4 DAN MFe2O4-SiO2 (M = Cu, Ni)". Jurnal Riset Kimia 4, n. 1 (11 febbraio 2015): 55. http://dx.doi.org/10.25077/jrk.v4i1.84.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Nanocomposites of MFe2O4 and MFe2O4-SiO2 (M= Cu, Ni) were prepared by complexation and complexs polymerization methods using citric acid as complexing agent, tetraethylorthosilicate (TEOS), metal (Cu, Ni) nitrate and iron chloride as precursors. FT-IR spectroscopy was used to analysis the complexation and polymerization process. The decomposition of material was investigated by TG-DTA. Microstructure characterization was carried out by XRD and SEM. Peaks in XRD pattern indicate that the nanocomposites products consist of copper iron oxide (CuFe2O4) and (NiFe2O4) crystals, copper iron oxide crystal distributed in silica (CuFe2O4-SiO2) and nickel iron oxide crystal distributed in silica (NiFe2O4-SiO2). SEM images of CuFe2O4 and NiFe2O4 show that the composites have porous and spherical texture. The surface texture of CuFe2O4-SiO2 composite is triangel like and has porous but NiFe2O4-SiO2 is not regulated texture and has porous. Keywords: MFe2O4, MFe2O4/SiO2, citric acid and complexs polymerization method

3

Rauch, Johannes, Frank Kern e Rainer Gadow. "Polarization Light Optical Texture Analysis for the Structural Characterization of CIM Components". Advances in Science and Technology 45 (ottobre 2006): 1690–95. http://dx.doi.org/10.4028/www.scientific.net/ast.45.1690.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The mechanical properties of ceramic injection molded (CIM) components are largely influenced by microstructural inhomogeneities that result from the interaction of rheological properties of the thermoplastic feedstock with machine parameters and the design of mold and injection gate. These inhomogeneities (e. g. texture, turbulences, joints, and density gradients) can form weak spots in the material or lead to anisotropy of the material properties. Additionally, they can influence the local sinter shrinkage behavior and thereby lead to the formation of residual stresses in the component. For this reason, it is of great importance to analyze these inhomogeneities in order to improve CIM processes and CIM components. A method has been developed for the investigation of preferred crystal orientation and microstructural defects, applying polarization microscopy of ceramic thin sections and colorimetry. Polarization microscopy is used in order to visualize the crystal orientation of the single grains. Different orientations of the optical axes will result in different colors of interference for optically uniaxial materials. The polarization micrographs themselves are already suitable for the analysis of the microstructure of CIM components regarding texture, separation planes, etc. Colorimetry is used in order to measure and describe the colors in a standardized color system. By means of color/orientation calibration curves that are measured with single crystal references, a quantitative description of the orientation of single grains as well as texturized areas can be obtained.

4

Viney, Christopher, e Wendy S. Putnam. "Characterization of sheared liquid crystalline polymers by light microscopy". Proceedings, annual meeting, Electron Microscopy Society of America 51 (1 agosto 1993): 864–65. http://dx.doi.org/10.1017/s0424820100150150.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

It is widely observed that nematic and cholesteric liquid crystalline materials develop a one-dimensional periodic microstructure during and/or after a uniaxial draw or simple shear (Fig. 1). This property is common to lyotropic and thermotropic examples of both small-molecule and polymeric liquid crystals. The periodic microstructure gives rise to a banded texture between crossed polars (Fig 2).A material under load will extend more readily if the microstructure contains crimps that can be straightened, compared to the extension that is achieved if covalent backbone bonds are highly aligned along the direction of load. The microstructure in Fig. 1 therefore is regarded as a stiffness-reducing defect. Two classes of stiff polymer that are produced from lyotropic solutions do not exhibit banded textures: the highest modulus variant of poly(p-phenyleneterephthalamide) (Kevlar), and various natural silk fibers. However, a banded texture is present in the less stiff variants of Kevlar, and also in silk fibers that have been drawn by hand from natural secretions, which demonstrates that the defect is not intrinsic to liquid crystalline molecular order, but is related to processing.

5

Chaudry, Umer Masood, Kotiba Hamad e Tea-Sung Jun. "Investigating the Microstructure, Crystallographic Texture and Mechanical Behavior of Hot-Rolled Pure Mg and Mg-2Al-1Zn-1Ca Alloy". Crystals 12, n. 10 (21 settembre 2022): 1330. http://dx.doi.org/10.3390/cryst12101330.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

In this study, the microstructure, crystallographic texture and the mechanical performance of hot-rolled pure Mg and Mg-2Al-1Zn-1Ca (herein inferred as AZX211) were thoroughly investigated. The results showed that the designed AZX211 alloy exhibited an exceptional strength/ductility synergy where an almost 40% increase in ductility was received for AZX211. The microstructural characterization revealed the grain refinement in the AZX211, where the grain size was reduced by more than 50% (24.5 µm, 10 µm for the pure Mg and the AZX211, respectively). Moreover, a discernible number of precipitates were dispersed in the AZX211, which were confirmed to be (Mg, Al)2Ca. The pure Mg showed a conventional strong basal texture while a significantly weakened split basal texture was received for the AZX211. The fraction of basal-oriented grains was 21% for the pure Mg and 5% for the AZX211. The significant texture weakening for the AZX211 can be attributed to the precipitation and co-segregation that triggered the preferential evolution of the non-basal grains while impeding the growth of the basal grains. This was also confirmed by the crystal orientation and the pseudo-rocking curves. The higher ductility of the AZX211 was explained based on the texture softening and Schmid factor for the basal and non-basal slip systems.

6

Zhang, Miao, e Shujie Liu. "Microstructure of laser cladding nickel-based superalloy: characterization, finite element modeling, and fatigue analysis". Journal of Physics: Conference Series 2184, n. 1 (1 marzo 2022): 012047. http://dx.doi.org/10.1088/1742-6596/2184/1/012047.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Abstract After laser cladding, the mechanical response of nickel-based single crystal superalloy is more complex when the loading direction is perpendicular to the columnar grain growth direction. In order to understand the deformation at grain level, a representative volume element (RVE) model based on the randomness of columnar grain texture was established for DD6 single crystal alloy, and the finite element model simulation of crystal plasticity (CPFEM) was performed. The results show that the stress and strain responses of the cladding microstructure are related to the grain distribution. The orientation difference between columnar grains in the epitaxial growth microstructure leads to non-uniform deformation and local stress concentration. The greater the crystal orientation difference is, the more obvious the stress concentration phenomenon is. On this basis, the statistical standard deviation of strain component is chosen to represent the fatigue damage of material, and the relationship between the statistical standard deviation of strain component and the external load strain is studied, which has certain reference value for the fatigue damage research of micro-cladding.

7

Black, David R. "Microstructural characterization using x-ray diffraction imaging". Proceedings, annual meeting, Electron Microscopy Society of America 51 (1 agosto 1993): 504–5. http://dx.doi.org/10.1017/s0424820100148356.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

X-ray diffraction imaging, also known as x-ray topography, is a powerful tool to study the defect microstructure of single crystals. As the name implies, this technique is based on recording an image of the diffracted x-ray beam from a crystal. Contrast in the image results from point-to-point variation in the diffracted intensity through the crystal. An example of a diffraction image is shown in figure 1. That this image is in some way a topographic representation of the sample can be seen in the impression of differing elevations and textures in different parts of the image. However, since this image is a result of diffraction from the sample the interpretation of the image is much more complex.Diffraction contrast is usually separated into two types: mosaic contrast and extinction contrast. Mosaic contrast occurs for crystals considered to be formed from a collection of small perfect crystal blocks. These blocks have a well defined rocking curve width, the angular range over which they will diffract, and may be slightly misoriented with respect to each other and/or may have different lattice spacing.

8

DiMasi, E., e M. Sarikaya. "Synchrotron x-ray microbeam diffraction from abalone shell". Journal of Materials Research 19, n. 5 (maggio 2004): 1471–76. http://dx.doi.org/10.1557/jmr.2004.0196.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Microstructured biomaterials such as mollusk shells receive much attention at present, due to the promise that advanced materials can be designed and synthesized with biomimetic techniques that take advantage of self-assembly and aqueous, ambient processing conditions. A satisfactory understanding of this process requires characterization of the microstructure not only in the mature biomaterial, but at the growth fronts where the control over crystal morphology and orientation is enacted. In this paper, we present synchrotron microbeam x-ray diffraction (XRD) and electron microscopy observations near the nacre–prismatic interface of red abalone shell. The relative orientations of calcite and aragonite grains exhibit some differences from the idealizations reported previously. Long calcite grains impinge the nacre–prismatic boundary at 45° angles, suggestive of nucleation on (104) planes followed by growth along the c axis. In the region within 100 μm of the boundary, calcite and aragonite crystals lose their bulk orientational order, but we found no evidence for qualitative changes in long-range order such as ideal powder texture or an amorphous structure factor. XRD rocking curves determined the mosaic of calcite crystals in the prismatic region to be no broader than the 0.3° resolution limit of the beamline’s capillary optics, comparable to what can be measured on geological calcite single crystals.

9

Claves, Steven R., Wojciech Z. Misiolek, William H. Van Geertruyden e David B. Williams. "Use of Electron Backscatter Diffraction Technique in Characterization of 6XXX Aluminum Alloy Extrusions". Microscopy and Microanalysis 6, S2 (agosto 2000): 954–55. http://dx.doi.org/10.1017/s1431927600037260.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Electron Backscattering Diffraction (EBSD) is an important tool for analyzing the crystal grain orientation of a microstructure and can be used to formulate conclusions about microtexture, texture determined from individual grains. This technique has been used to study a 6xxx series aluminum alloy's response to the deformation of the extrusion process. Extrusion is the process by which a billet of material is forced, under high pressure, through a die. The material undergoes a significant decrease in cross sectional area, and is formed into a shape equivalent to the geometry of the die orifice. Different bearing lands are shown in shown in Figure 1. These surfaces form the part, and are designed to control the metal flow making it uniform through the die, thus yielding good mechanical properties. This research was focused on the resultant microstructure. The shaded regions of Figure 2 show the two surface regions where EBSD measurements were taken.

10

Habibi, Niloufar, Napat Vajragupta e Sebastian Münstermann. "Deformation and Damage Assessments of Two DP1000 Steels Using a Micromechanical Modelling Method". Crystals 11, n. 7 (10 luglio 2021): 805. http://dx.doi.org/10.3390/cryst11070805.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Damage characterization and micromechanical modelling in dual-phase (DP) steels have recently drawn attention, since any changes in the alloying elements or process route strongly influence the microstructural features, deformation behavior of the phases, and damage to the micro-mechanisms, and subsequently the particular mechanical properties of the material. This approach can be used to stablish microstructure–properties relationships. For instance, the effects of local damage from shear cutting on edge crack sensitivity in the following deformation process can be studied. This work evaluated the deformation and damage behaviors of two DP1000 steels using a microstructure-based approach to estimate the edge cracking resistance. Phase fraction, grain size, phase distribution, and texture were analyzed using electron backscatter diffraction and secondary electron detectors of a scanning electron microscope and employed in 3D representative volume elements. The deformation behavior of the ferrite phase was defined using a crystal plasticity model, which was calibrated through nanoindentation tests. Various loading conditions, including uniaxial tension, equi-biaxial tension, plane strain tension, and shearing, along with the maximum shear stress criterion were applied to investigate the damage initiation and describe the edge cracking sensitivity of the studied steels. The results revealed that a homogenous microstructure leads to homogenous stress–strain partitioning, delayed damage initiation, and high edge cracking resistance.

11

Mania, I., H. Paul, R. Chulist, P. Petrzak e M. Prażmowski. "Crystallographic aspect of shear bands formation in pure iron deformed at high strain rates". IOP Conference Series: Materials Science and Engineering 1270, n. 1 (1 dicembre 2022): 012099. http://dx.doi.org/10.1088/1757-899x/1270/1/012099.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

In this paper results on shear bands developed in pure iron are presented. The main focus was put on microstructural characterization and crystal lattice rotation in sheared regions. The hat-shaped samples were deformed at a high strain rate of 560 s−1 using a drop-hammer. The microstructure of deformed specimen was investigated by optical microscopy and scanning electron microscopy equipped with a high-resolution electron backscattered diffraction facility. The changes of mechanical properties in the band area and neighbouring matrix were investigated using nano-indentation test. This paper clearly shows that initial stages of shear bands formation are associated with the formation of kink-type bands. The orientation maps revealed the crystallographic determination of the shear band formation. During deformation in each grain located within the sheared region, one of the {110}-type planes situate along the macro-shear band plane and <111> direction situates along the shear direction. In consequence, the formation of specific texture components within the shear band region was observed, different from texture observed in deformed matrix. In micro-scale no effects of dynamic recrystallization were observed. Nano-hardness tests indicated that notable increase of strain hardening is related to the strain localization in narrow shear band’ regions, while the matrix undergoes almost no deformation.

12

Luo, Z. X., J. P. He, D. Y. Li e Y. H. Peng. "Crystal plasticity modeling on the selective laser melted AlSi10Mg alloy". IOP Conference Series: Materials Science and Engineering 1270, n. 1 (1 dicembre 2022): 012024. http://dx.doi.org/10.1088/1757-899x/1270/1/012024.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Additive manufacturing (AM) has been developing into a revolutionary technique, in which parts are created by additive processing as opposed to the conventional subtractive manners. AM components possess the characterization of special microstructure and porosity. In this paper, a computational method is developed to investigate the mechanical property of selectively laser melted (SLM) AlSi10Mg alloy. The DREAM.3D software is utilized to generate a polycrystal model based on electron backscatter diffraction (EBSD) results. The investigated alloy shows a weak texture that the grain preferential grows along the <100> orientation. The real defect geometries are reconstructed from X-ray Computed Tomography (XCT) experimental slices and embedded into a representative volume element (RVE) model. Furthermore, a crystal plasticity (CP) model integrated fast Fourier transform method (FFT) in Düsseldorf Advanced Material Simulation Kit (DAMASK) package is implemented to simulate the mechanical response for the RVE model. The effect of porosity on tensile strength is studied, and result shows the defects degrade tensile strength.

13

Coghe, Frederik, Wim Tirry, Luc Rabet e Paul van Houtte. "Characterization and Modeling of Twinning in a Titanium Alloy Ti-6Al-4V". Materials Science Forum 702-703 (dicembre 2011): 237–40. http://dx.doi.org/10.4028/www.scientific.net/msf.702-703.237.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The twinning behavior of a commercial Ti-6Al-4V alloy is studied using a combined experimental and numerical approach. An extensive microstructural investigation was performed to identify and quantify the active twin systems. The mechanical behavior as a function of initial texture and strain rate was then modeled using a visco-plastic self-consistent crystal plasticity code (VPSC7). Earlier obtained quasi-static and dynamic data served to fit the parameters of the model, giving good agreement. However, even if the model gave qualitatively good predictions of the stress-strain curves and the texture evolution for the different loadings, the calculated twin fractions differed considerably of the experimental results.

14

Lim, Ji-Eun, Jae Kyeong Jeong, Kun Ho Ahn, Hyeong Joon Kim, Cheol Seong Hwang, Dong-Yeon Park e Dong-Su Lee. "Microstructural characterization of sputter-deposited Pt thin film electrode". Journal of Materials Research 19, n. 2 (febbraio 2004): 460–68. http://dx.doi.org/10.1557/jmr.2004.19.2.460.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Pt thin films of various thicknesses (30 nm ∼ 200 nm) were deposited on Si wafers with SiO2, Ti, TiO2, or IrO2 buffer layers at various temperatures (room temperature ∼200 °C) by a direct current magnetron sputtering process. The Pt films showed a strong (111)-preferred texture irrespective of the thickness, under-layer, and growth temperature. The authors previously reported [J-E. Lim, D-Y. Park, J.K. Jeong, G. Darlinski, H.J. Kim, and C.S. Hwang, Appl. Phys. Lett. 81, 3224 (2002)] that the films were composed of three kinds of grains with slightly different (111) lattice parameters (bulklike, 1.0% and 2.1% larger). This study details the microstructural variations of the Pt films according to the variations of experimental parameters. The different deposition conditions produced slightly different crystalline structures, but the three different (111) lattice parameters were always found. Epitaxial (200) Pt films on a (200) MgO substrate and a highly (111) textured Au thin film on a SiO2/Si did not show the same splitting in the lattice parameter. The grains with 1.0% and 2.1% larger (111) lattice parameter almost disappeared after postannealing at 1000 °C. However, surface chemical binding of the Pt film before and after annealing was unchanged. Therefore, it is believed that the lattice parameter splitting in the (111) textured Pt film originated from the interfacial grains with the distorted crystal structure due probably to growth stress.

15

Sperling, Evan A., Rajarshi Banerjee, Gregory B. Thompson, Jason P. Fain, Peter M. Anderson e Hamish L. Fraser. "Processing and microstructural characterization of sputter-deposited Ni/Ni3Al multilayered thin films". Journal of Materials Research 18, n. 4 (aprile 2003): 979–87. http://dx.doi.org/10.1557/jmr.2003.0134.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The crystallographic texture, orientation relationships, coherency stress, and thermal stability of sputter-deposited Ni/Ni3Al multilayered thin films were studied as a function of bilayer period (Λ) as well as processing parameters such as substrate type, deposition temperature, and prebake conditions. Deposition onto oxidized Si or single-crystal Cu(001), NaCl(001), or KBr(001) substrates near room temperature produces multilayers with a [111] crystallographic texture along the Ni/Ni3Al interface normal and a disordered face-centered cubic structure for the Ni3Al phase. In contrast, deposition at 673 K onto NaCl(001) or KBr(001) substrates that are prebaked in vacuum at 693 K produces a chemically ordered L12 structure for the Ni3Al phase and (001) epitaxial growth. X-ray diffraction measurements of (001) multilayers with equal volume fraction of Ni and Ni3Al reveals a transition from a nearly incoherent state at Λ=40 nm to a semicoherent one at Λ 40 nm. Remarkably, (001) multilayers were observed to solutionize at 1373 K, which is approximately 100 K below that predicted by the Ni–Al phase diagram.

16

Zhu, Zhaoge, Longqing Zou, Huaxing Li e Hongbin Zhang. "Preparation and Characterization of Pulse Electrodeposited Ni/W-SiC Nanocomposite Coating on Mild Steel Substrate". Coatings 13, n. 3 (21 febbraio 2023): 484. http://dx.doi.org/10.3390/coatings13030484.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

In order to improve the performances of metal containers, furnace bodies and agricultural tools manufactured by mild steels, Ni/W-SiC nanocomposites are prefabricated on mild steel substrate by the pulse electrodeposition (PED) method. The morphology, texture, microstructure, microhardness, and wear performances of Ni/W-SiC nanocomposites are examined by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), dispersive X-ray spectroscopy (EDX), hardness tester, and friction wear testing. The results indicate that the SiC size in nanocomposites is ~32.4 nm when its concentration in electrolytes is 7 g/L. The S1 and S4 nanocomposites’ microstructures (the S1 composite was prefabricated at 4 g/L, and the S4 composite was deposited at 13 g/L) reveal many large cauliflower-shaped grains. However, the S2 nanocomposite (the S2 composite was obtained at 7 g/L) demonstrates the homogeneous, finest and smoothest surface morphology. The diffraction angles of S1 nanocomposite are 41.2°, 51.7°, and 71.2° depicting the sharpest diffraction peaks, corresponding to the (1 1 1), (2 0 0), and (2 2 0) crystal planes of Ni-W grains, respectively. Moreover, the S2 nanocomposite exhibits the lowest wear depth and width of 34.2 μm and 5.5 mm, respectively. Some shallow and fine scratches on the as-described nanocomposites’ surface indicate its excellent tribological performance. However, the S4 nanocomposite exhibits a wear depth of 86.3 μm and a width of 11.9 mm.

17

He, You Liang, Mehdi Mehdi, Erik J. Hilinski, Tom Zhou, Peter Badgley, Leo A. I. Kestens e Afsaneh Edrisy. "Shear Banding in Rotated Goss Grains and its Effect on the Formation of Cube Texture in Non-Oriented Electrical Steel". Materials Science Forum 1016 (gennaio 2021): 528–33. http://dx.doi.org/10.4028/www.scientific.net/msf.1016.528.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Cube texture ({001}<100>) is a desired final texture in non-oriented electrical steel sheets used as magnetic cores because it contains two easy <100> axes in the sheet plane, which is beneficial to the magnetic properties. However, the cube texture is very difficult to form in non-oriented electrical steels through conventional rolling and annealing. It has been shown that after conventional rolling, the deformed <111>//ND (normal direction) grains provided nucleation sites for the unfavourable <111>//ND texture during recrystallization, leading to a final <111>//ND texture. To eliminate the <111>//ND texture and promote the {001}<100> texture, an uncommon rolling process, i.e. inclined rolling, was adopted in this study. By rotating the hot rolling direction by 60° around the ND, an uncommon initial texture, the rotated Goss ({110}<110>), was intentionally generated. This was intended to change the orientation flow during plastic deformation, and suppress the formation of the conventional <111>//ND texture in the deformed microstructure. Plane-strain compression (rolling) of the rotated Goss grains produced shear bands within these grains due to their large Taylor factor. Electron backscatter diffraction (EBSD) characterization of the shear bands illustrated that, crystallites with the cube orientation were formed within these shear bands. During recrystallization, the shear bands provided preferential nucleation sites, and the cube crystallites preferentially nucleate within the shear bands. These cube crystals can then grow into the deformed matrix, and lead to the formation of a strong cube texture in the final annealed steel sheets.

18

WEI, CHUN, QIU-SHAN GAO, YONG-YANG GONG, XUE-MEI XIONG e XIN SHEN. "SYNTHESIS AND CHARACTERIZATION OF A RODLIKE LIQUID CRYSTALLINE POLYURETHANE OLIGOMER". Functional Materials Letters 03, n. 03 (settembre 2010): 169–72. http://dx.doi.org/10.1142/s1793604710001172.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

A novel rodlike liquid crystalline polyurethane (LCPU) oligomer was synthesized by polyaddition of hexane-1,6-diylbis(4-hydroxybenzoate) with toluene 2,4-diissocyanate in N, N′-dimethylformamide solution. The properties of the LCPU oligomer were investigated by FT-IR, DSC, TGA, POM, WAXD and SEM. The LCPU oligomer was a yellow powder at room temperature, which maintained a stable rodlike microstructure below its melting point, and had high crystallinity. The LCPU oligomer exhibited thermotropic liquid crystalline properties between 166–183°C, and the smectic-A phase with focal conic fan textures at the liquid crystal state was observed by POM. The decomposition temperature of the LCPU oligomer at 5% weight loss was 282°C.

19

Sutliff, J. A., e B. P. Bewlay. "Orientation Imaging of A Nb-Ti-Si Directionally Solidified In-Situ Composite". Proceedings, annual meeting, Electron Microscopy Society of America 54 (11 agosto 1996): 350–51. http://dx.doi.org/10.1017/s0424820100164210.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

In this paper we report on the microstructural characterization of a directionally solidified (DS) Nb-Ti-Si alloy. The solidified ingot had a nominal composition of Nb-33 at%Ti-16 at% Si and was grown using the Czochralski technique with growth rate of 5 mm/min. The as-solidified ingot was approximately 50 mm long with a 10 mm diameter. The microstructure was examined using backscatter electron imaging and the microtexture of each of the phases was determined using the Electron BackScattering Pattern (EBSP) technique for electron diffraction in the scanning electron microscope. The details of the experiments are similar to those we have reported previously. Automated EBSP scans were acquired in order to map the local texture (microtexture) over most of a transverse cross-section through the ingot.Figure 1 is a backscattered electron image (BEI) of a transverse section of the as-solidified microstructure. In this image, the bcc-Nb phase is the lighter gray phase and has a dendritic structure. The dark gray phase is (Nb,Ti)3Si having a Ti3P crystal structure. The silicide phase appears as both multiply-faceted dendrites and irregularly bounded grains. A pattern of shading, due to Ti segregation, can be seen in figure 1 and suggests a cellular solidification structure. Figure 2 is a BEI taken at higher magnification to show a region that was analyzed by automated-EBSP. Figure 3 contains orientation images generated from the automated-EBSP data set. In Figure 3a, the color black signifies positions for which no Nb diffraction patterns could be indexed and other shades of gray signify specific Nb orientations, as described by a set of Euler angles. A similarly generated orientation image for the silicide phase is shown in Figure 3b. The greyscale image presented here is actually a rendering of a truecolor image based on a RGB triplet using the Euler angles.

20

Hailong, Liang, Li Ruiqin, Wang Hongfu e An Hong En. "Study on Microstructure Refinement Mechanism in Deeply Supercooled Solidification of Ni-25at.%Cu Alloys". Science of Advanced Materials 13, n. 11 (1 novembre 2021): 2250–58. http://dx.doi.org/10.1166/sam.2021.4156.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Maximum undercooling degrees were obtained by glass purification and superheating. Rapid solidification in an undercooled alloy was systematically studied. As the undercooling increases, the solidification front appears randomly. The microstructure undergoes a transformation from coarse dendrite grains to granular grains to oriented dendrite to equiaxed crystal. The results show two grain refinement under high and low undercooling. No high strength textures are found under high undercooling conditions, and many grain boundaries of high angle nature are observed, which confirms recrystallization. In the TEM characterization of high undercooling, high density dislocation strain indicates that accumulated stress in the rapid solidification process induces microstructure plastic strain and promotes recrystallization. The results show that the grain boundary of refined grain is coarser at low undercooling, but narrower at high undercooling. Twins and subgrains observed at large undercooling indicate that the grain refinement mechanisms are very different.

21

Chen, Furong, e Chenghao Liu. "Improving the Properties of Laser-Welded Al–Zn–Mg–Cu Alloy Joints by Aging and Double-Sided Ultrasonic Impact Compound Treatment". Materials 14, n. 11 (22 maggio 2021): 2742. http://dx.doi.org/10.3390/ma14112742.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

To improve the loose structure and serious porosity of (Al–Zn–Mg–Cu) 7075 aluminum alloy laser-welded joints, aging treatment, double-sided ultrasonic impact treatment (DSUIT), and a combination of aging and DSUIT (A–DSUIT) were used to treat joints. In this experiment, the mechanism of A–DSUIT on the microstructure and properties of welded joints was analyzed. The microstructure of the welded joints was observed using optical microscopy, scanning electron microscopy, and electron backscatter diffraction (EBSD). The hardness and tensile properties of the welded components under the different processes were examined via Vickers hardness test and a universal tensile testing machine. The results showed that, after the aging treatment, the dendritic structure of the welded joints transformed into an equiaxed crystal structure. Moreover, the residual tensile stress generated in the welding process was weakened, and the hardness and tensile strength were significantly improved. After DSUIT, a plastic deformation layer of a certain thickness was generated from the surface downward, and the residual compressive stress was introduced to a certain depth of the joint. However, the weld zone unaffected by DSUIT still exhibited residual tensile stress. The inner microhardness of the joint surface improved; the impact surface hardness was the largest and gradually decreased inward to the weld zone base metal hardness, with a small improvement in the tensile strength. Compared with the single treatment process, the microstructural and mechanical properties of the welded joint after A–DSUIT were comprehensively improved. The microhardness and tensile strength of the welded joint reached 200 HV and 615 MPa, respectively, for an increase of 45.8% and 61.8%, respectively. Observation of the fractures of the tensile specimens under the different treatment processes showed that the fractures before the aging treatment were mainly ductile fractures while those after were mainly brittle fractures. After DSUIT of the welded joints, a clear and dense plastic deformation layer was observed in the fracture of the tensile specimens and effectively improved the tensile properties of the welded joints. Under the EBSD characterization, the larger the residual compressive stress near the ultrasonic impact surface, the smaller the grain diameter and misorientation angle, and the lower the texture strength. Finally, after A–DSUIT, the hardness and tensile properties improved the most.

22

Zuo, J. M. "Automation in electron diffraction analysis". Proceedings, annual meeting, Electron Microscopy Society of America 53 (13 agosto 1995): 170–71. http://dx.doi.org/10.1017/s0424820100137227.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Automated lattice parameter measurement and orientation analysis are often needed in the characterization of microstructures using electron diffraction, and is made possible with increasingly popular use of slow scan CCD camera and imaging plates. Both of these two detectors are largely linear and digital. Typical electron diffraction analysis has three steps: 1) diffraction pattern measurement, 2) diffraction pattern indexing and 3) solution. Full automation in all these three steps is desired, however, may be hard to achieve especially for complex crystal structures. The importance of automation in each of these steps depends on the type of analysis and the number of analysis needed. Full automation is necessary in the type of applications where the same analysis is repeated many times, such as in texture analysis. In table 1, various applications of electron diffraction and automation needed are listed.There are two types of approach to the automatic indexing. The commonly used method is to matching a calculated list of g's with the measured ones.

23

Cook, Phil K., Cristian Mocuta, Élise Dufour, Marie-Angélique Languille e Loïc Bertrand. "Full-section otolith microtexture imaged by local-probe X-ray diffraction". Journal of Applied Crystallography 51, n. 4 (26 luglio 2018): 1182–96. http://dx.doi.org/10.1107/s1600576718008610.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

An optimized synchrotron-based X-ray diffraction method is described for the direct and efficient measurement of crystallite phase and orientation at micrometre resolution across textured polycrystalline samples of millimetre size (high scale dynamics) within a reasonable time frame. The method is demonstrated by application to biomineral fish otoliths. Otoliths are calcium carbonate accretions formed in the inner ears of vertebrates. Fish otoliths are essential biological archives, providing information for individual age estimation, the study of population dynamics and fish stock management, as well as past environmental and climatic conditions from archaeological specimens. Here, X-ray diffraction mapping is discussed as a means of describing the mineralogical structure and microtexture of otoliths. Texture maps could be generated with a fewa priorihypotheses on the aragonitic system. Full-section imaging allows quantitative intercomparison of crystal orientation coupled to microstructural description, across the zones of the otoliths that represent distinctive mineral organization. It reveals the extents of these regions and their internal textural structure. Characterization of structural and textural correlations across whole images is therefore proposed as a complementary approach to investigate and validate the local in-depth nanometre-scale study of biominerals. The estimation of crystallite size and orientational distribution points to diffracting domains intermediate in size between the otolith nanogranules and the crystalline units, in agreement with recently reported results.

24

Sanchez-Mata, Oscar, Xianglong Wang, Jose Alberto Muñiz-Lerma, Sıla Ece Atabay, Mohammad Attarian Shandiz e Mathieu Brochu. "Characterization of the microstructure and mechanical properties of highly textured and single crystal Hastelloy X thin struts fabricated by laser powder bed fusion". Journal of Alloys and Compounds 901 (aprile 2022): 163465. http://dx.doi.org/10.1016/j.jallcom.2021.163465.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

25

Park, H., e J. A. Szpunar. "The Microstructural Characterization of Electrogalvanized Zinc–Iron and Zinc–Nickel Coatings". Textures and Microstructures 34, n. 2-3 (1 gennaio 2000): 119–46. http://dx.doi.org/10.1155/tsm.34.119.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

In this study, the development of the microstructure of zinc–iron and zinc–nickel coatings on steel sheet electrodeposited at various deposition conditions, is analyzed. The evolution of the coating microstructure – texture, surface morphology, crystallographic lattice, microstress, alloy composition and phase of coatings – is investigated at different current densities and deposition times. The microstructure of zinc alloy coatings varies significantly with the change of deposition parameters. The present study proposes that the transformarion of texture during the alloy codeposition is closely related to the morphological characteristics of the coating surface and the change of alloy and phase composition of the deposit. Anomalous codeposition behavior, is considered responsible for the change or transformation of the microstructure of coatings. The texture of zinc–iron coatings changes from the combined texture of the basal fiber and non-fiber pyramidal component to the pyramidal fiber texture with the current density increase. In the case of zinc–nickel coatings, the intensity of the {101} texture of γ phase increases with increasing nickel content, while the intensity of the {100} texture decreases. A correlation between the texture, morphology and alloy content in the deposits is discussed.

26

Walker, T., N. Mattern e M. Herrmann. "Texture and Microstructure in Hot-Pressed Si3N4". Textures and Microstructures 24, n. 1-3 (1 gennaio 1995): 75–91. http://dx.doi.org/10.1155/tsm.24.75.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The texture formation in hot-pressed Si3N4-ceramics was investigated by means of X-ray diffraction. A ring-fibre texture is observed with the basal plane (002) perpendicular to the hot-pressing axis. The texture index of hot-pressed Si3N4 depends on the starting powder mixture and process parameters. The α→β phase transfomation and the growth of β-Si3N4 needlelike grains are correlated with the texture. Measurements of fracture toughness and aspect ratio confirm the correlation with microstructure. The structure is the result of crystal growth and flow process during hot-pressing.

27

Goran, D., Jean-Jacques Fundenberger, Satyam Suwas, Emmanuel Bouzy, László S. Tóth, Werner Skrotzki e Thierry Grosdidier. "Pure Ni Single Crystal of Cube Orientation Deformed by Equal Channel Angular Extrusion". Solid State Phenomena 105 (luglio 2005): 333–38. http://dx.doi.org/10.4028/www.scientific.net/ssp.105.333.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Texture and microstructure were investigated after 1 pass equal channel angular extrusion (ECAE) of a single crystal cube oriented Ni billet. Neutron and X-ray diffraction were used to determine global and local textures, respectively. To investigate the fine scale microstructural features EBSD was used. Substantial variations in texture and microstructure resulting from different efficiencies in the shearing process were locally recorded through the billet height.

28

Penelle, Richard, e Thierry Baudin. "Multiscale Approach to Texture-Microstructure Coupling". Materials Science Forum 509 (marzo 2006): 1–10. http://dx.doi.org/10.4028/www.scientific.net/msf.509.1.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Materials exhibit microstructures and textures that influence their use and properties. Xray and neutron diffraction allow characterization of the bulk texture, whereas Electron Backscattered Diffraction (EBSD) permits determination of the local texture. In many cases Transmission Electron Microscopy (TEM) remains necessary to characterize the substructure and the local texture for highly deformed materials. Depending on the scale considered, all these complementary techniques permit the coupling of texture and microstructure so that it becomes possible to control microstructure and its evolution during a processing route. Some examples in titanium aluminides, (α + β) titanium alloys and an Fe-Ni alloy will illustrate this challenge.

29

Jakubowska, D., J. Zdunek, M. Kulczyk, J. Mizera e K. J. Kurzydłowski. "Microstructure Evolution and Texture Development in a Cu-8.5%AT. AL Material Subjected to Hydrostatic Extrusion". Archives of Metallurgy and Materials 61, n. 2 (1 giugno 2016): 933–36. http://dx.doi.org/10.1515/amm-2016-0158.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

AbstractThe aim of the present paper was to investigate microstructure and texture evolution of two single crystals and polycrystal of Cu-8.5%at.Al material. All of mentioned samples were deformed by HE to achieve true strain ε = 1.17. For microstructure analyzes observations by transmission electron microscope (STEM) were done. Crystalline size for samples after SPD were determine using XRD method. The global texture measurements were done using Bruker D8 Discover diffractometer equipped in Cr radiation. Microstructure investigations revealed nanocrystalline structure in single crystals with initial orientations <110> and <100> and polycrystalline Cu-8.5%at.Al material after SPD. The global texture measurements have shown the stability of initial orientation of <100> Cu-8.5%at.Al single crystal after HE, whereas the same SPD process strongly brakes up the orientation <110> Cu-8.5%at. Al single crystal.

30

El-Danaf, Ehab, Muneer Baig, Abdulhakim Almajid, Waleed Alshalfan, Marawan Al-Mojil e Saeed Al-Shahrani. "Mechanical, microstructure and texture characterization of API X65 steel". Materials & Design 47 (maggio 2013): 529–38. http://dx.doi.org/10.1016/j.matdes.2012.12.031.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

31

Kishida, Kyosuke, Masahiko Demura e Toshiyuki Hirano. "Anisotropy in Cold Rolling of Single Crystalline Ni₃-Al-Base Intermetallic Alloys". Materials Science Forum 495-497 (settembre 2005): 737–42. http://dx.doi.org/10.4028/www.scientific.net/msf.495-497.737.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Texture and microstructure evolution during cold rolling of binary Ni3Al single crystals were studied as a function of the initial crystal orientations. Cold rolling behavior of the single crystals is strongly dependent on the initial crystal orientations, especially on the initial rolling direction (RD). Macroscopic texture evolutions for binary Ni3Al single crystals with the initial RD close to <001> are characterized as development of dual {110}<¯112> texture above 90% cold reduction and the banded structure formation. Microstructure observations reveal the extensive formation and accumulation of the planar defects including the stacking faults and the planes where the localized shear deformations occurs, which must be responsible for the observed anisotropic cold rolling behavior of Ni3Al single crystals.

32

Jin, Zi Li, Wei Li e Yi Ming Li. "Effect of Hot-Rolled Microstructure on the Recrystallization Texture of Cold-Rolled Non-Oriented Electrical Steel". Advanced Materials Research 298 (luglio 2011): 203–8. http://dx.doi.org/10.4028/www.scientific.net/amr.298.203.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

With the help of orientation distribution function (ODF) analysis, experiments of different hot band grain microstructure 0.33% silicon steel were cold-rolled and annealed in the laboratory，to study the effect of the microstructure hot-rolled steel strip for cold rolled non-oriented silicon steel microstructure and texture of recrystallization annealing. The results show that hot rolled microstructure on cold rolled Non-Oriented Electrical Steel cold-rolled sheet evolution of texture and recrystallization have important influence, the quiaxed grain structure of steel by cold rolling and recrystallization annealing, the recrystallization speed than the fiber grain-based mixed crystals recrystallization fast , With the equiaxed grains made of cold rolled silicon steel after annealing the {110}<UVW> texture components was enhanced and {100}<uwv> texture components weakened. Different microstructure condition prior to cold rolling in the recrystallization annealing process the texture evolution has the obvious difference, the equiaxial grain steel belt cold rolling and annealing, has the strong crystal orientation. This shows that the equiaxed grain when hot microstructure is detrimental to the magnetic properties of cold-rolled non-oriented silicon steel to improve and increase.

33

Petrov, Roumen H., Orlando León García, J. J. L. Mulders, Ana Carmen C. Reis, Jin Ho Bae, Leo Kestens e Yvan Houbaert. "Three Dimensional Microstructure–Microtexture Characterization of Pipeline Steel". Materials Science Forum 550 (luglio 2007): 625–30. http://dx.doi.org/10.4028/www.scientific.net/msf.550.625.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The microstructural anisotropy together with the crystallographic texture of an industrial grade of X70 pipeline steel is studied by means of the 3D-EBSD technique known also as EBS3 which was recently developed by FEI. Samples of size 8x10x3mm³ were cut from the middle thickness of an industrial rolled plate and after special sample preparation have been studied in a Nova 600 dual beam scanning electron microscope equipped with a field emission gun and HKL Channel 6 EBSD data collection software for crystallographic orientation, which allows multiple sectioning of the sample in automatic mode and, afterwards reconstruction of both the 3D microstructure and texture of the examined volume. Three scanned zones of different volumes that varied between 15x10x27 4m³ and 16x14x6 4m³ have been examined and the results for the crystallographic orientation, grain shape and grain shape orientation are discussed together with the data for the anisotropy of the Charpy impact toughness of the material.

34

Wang, Zhi Gang, Zheng Zhi Zhao, Ai Min Zhao e Jie Yun Ye. "Microstructure and Recrystallization Texture Characterization of Cold-Rolled Dual-Phase Steel". Advanced Materials Research 430-432 (gennaio 2012): 1223–26. http://dx.doi.org/10.4028/www.scientific.net/amr.430-432.1223.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Deep drawing dual phase steel was designed and trial-produced in the laboratory. The microstructure and recrystallization texture was studied using OM,TEM and XRD techniques. The results show that texture components typically in DP steels are γ (<111>//ND) and α (<110>//RD) fibers, which is partly attributed to the precipitation of Mo-based carbides in hot-rolled plate. Besides, {554}<225> and {332}<113> texture components are also founded in deep drawing DP steels, which are beneficial to improvement of drawability. With the increasing of annealing temperature, the tensile strength and elongation of DP steels are increased and decreased, respectively, and the r value is reduced slightly.

35

Chateigner, Daniel, Philippe Blanchart, Sarah Deniel, Luca Lutterotti e Hans Rudolf Wenk. "Characterization of Microstructure and Crystallographic Texture of Silicate and Phyllosilicate Ceramics". Advances in Science and Technology 68 (ottobre 2010): 13–22. http://dx.doi.org/10.4028/www.scientific.net/ast.68.13.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

We illustrate the x-ray Combined Analysis approach capabilities in characterizing silicates and phyllosilicates for samples exhibiting crystallographic textures. Two mullite composite ceramics, one elaborated under uniaxial pressure the other under centrifugation, and one uniaxially pressed montmorillonite aggregate, are studied in terms of texture, cell parameters and phase contents. Several weak texture components are present in the mullite samples, combinations of planar- and fibre-like textures. The methodology is able to take account of the amorphous silica-like matrix of the composite, and cell parameters and structure of mullite correspond to the commonly modelled used for this phase. The montmorillonite turbostratic phase is correctly reproduced with its fibre texture, eventhough minor phases are also present and modelled in the aggregate.

36

Rodriguez-Calvillo, Pablo, N. Salazar, Juergen Schneider e Yvan Houbaert. "Microstructure Characterization by EBSD of Hot Rolled High-Silicon Steel". Defect and Diffusion Forum 273-276 (febbraio 2008): 69–74. http://dx.doi.org/10.4028/www.scientific.net/ddf.273-276.69.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Non oriented electrical steels are soft magnetic materials used in the core of electrical motors. No preferential anisotropy of the electrical texture in the rolling plane is desired. Nowadays these special steels are mainly alloyed with Si, Al and some additives to improve the magnetic properties and to reach a good of formability. For (Si, Al)-concentrations higher than 2 wt.% the α- γ-α phase transformation is suppressed, resulting in a bcc crystalline structure from liquidus to room temperature. These electrical steels, which will be discussed in the paper, exhibit the lowest values of the magnetic losses. Hot rolling of FeSi electrical steels has been found to be one of the fundamental steps in producing these materials with optimum properties. The resulting properties, as well known, are determined by the type of magnetic textures and the structural inhomogeneities. Electron Backscattered Diffraction (EBSD) is a reliable tool for microstructural and texture characterization of different materials. Two compositions of electrical steel are studied by optical microscopy and EBSD, with special attention paid to characterize the grain morphology and its texture through thickness.

37

Bonarski, Jan T. "Quantification of Texture Inhomogeneity". Materials Science Forum 495-497 (settembre 2005): 149–56. http://dx.doi.org/10.4028/www.scientific.net/msf.495-497.149.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

In the paper some aspects of analysis of crystallographic texture concerned to evaluation^of its inhomogeneity have been described. The introduced classification and quantitative measure of texture inhomogeneity have been applied in microstructure characterization of cold rolled Cu-sheet and of electrodeposited Cu-layer with a depth-graded structure.

38

Ostafin, M., Jan Pospiech e Robert A. Schwarzer. "Microstructure and Texture in Copper Sheets after Reverse and Cross Rolling". Solid State Phenomena 105 (luglio 2005): 309–14. http://dx.doi.org/10.4028/www.scientific.net/ssp.105.309.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The objectives of this investigation are structural effects in electrolytic copper sheets which are caused by the change of the direction of rolling. Unidirectional, reverse as well as cross-rolling at 90° respectively at 45° to the precedent rolling direction have been applied down to final deformations as low as 80% reduction in thickness. Texture has been determined by ACOM (Automated Crystal Orientation Measurement, “Automated EBSD”) in the SEM and by X-ray pole figure measurement. The main benefits of ACOM are a high spatial resolution which enables the investigation of texture gradients from the mid plane to the surface of the sheet, and the visualization of the microstructure by crystal orientation mapping. In addition to local texture, statistical distributions of misorientations across grain boundaries and of S grain boundaries have been derived from the individual grain orientation data. The change of the path of plastic deformation induces a destabilization of the substructure which is formed during the primary step of unidirectional rolling. A distinct change of texture is found depending on the deformation process. In cross rolling, the b fiber changes into the unstable b90 fiber which almost disappears with progressive deformation along the new rolling direction.

39

Goran, D., Jean-Jacques Fundenberger, Satyam Suwas, Emmanuel Bouzy, László S. Tóth, Werner Skrotzki e Thierry Grosdidier. "Heterogeneity of Deformation in Pure Ni Single Crystal of Cube Orientation Deformed by Equal Channel Angular Extrusion". Materials Science Forum 495-497 (settembre 2005): 833–38. http://dx.doi.org/10.4028/www.scientific.net/msf.495-497.833.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Texture and microstructure were investigated after 1 pass equal channel angular extrusion (ECAE) of a single crystal cube oriented Ni billet. Neutron and X-ray diffraction were used to determine global and local textures, respectively. EBSD and TEM investigations were also carried out in order to study fine scale microstructural features. Substantial variations in texture and microstructure, resulting from different efficiencies in the shearing process, were locally recorded through the billet height. The deformation was heterogeneous on both micro and macro scales.

40

Jakubowska, D., J. Zdunek, M. Kulczyk, J. Mizera e K. J. Kurzydłowski. "Microstructure and Texture of Hydrostatic Extrusion Deformed Ni Single Crystals and Polycrystal". Advances in Materials Science and Engineering 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/613839.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The differences in the microstructure and texture of two Ni single crystals, with different initial orientations (100and110), and of polycrystalline nickel, before and after severe plastic deformation (SPD) produced by hydrostatic extrusion (HE), have been investigated. The crystals were deformed by a two-step HE process with a total deformation value ofε=1.2. The global texture, mechanical properties, and microstructure were examined after the deformation. In every investigated sample, the presence of111fibre texture was noted, while the starting orientation of a100Ni single crystal was preserved in 50% of the volume. The results obtained were compared with the relevant literature data.

41

Chen, Jian, Wen Yan, Bing Li, XiaoGuang Ma, XinZhi Du e XinHui Fan. "Microstructure and texture evolution of cold drawing 〈110〉 single crystal copper". Science China Technological Sciences 54, n. 6 (12 aprile 2011): 1551–59. http://dx.doi.org/10.1007/s11431-011-4349-5.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

42

Chen, Jian, Wen Yan, Jian Miao, Chunxia Liu e Xinhui Fan. "Microstructure and Texture Evolution of Cold-Drawn 〈111〉 Single-Crystal Copper". Metallurgical and Materials Transactions A 42, n. 8 (22 marzo 2011): 2373–83. http://dx.doi.org/10.1007/s11661-011-0654-7.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

43

Liu, Xu, Ruiling Jia, Huixia Zhang, Wenhua Cheng e Xiwei Zhai. "EBSD Characterization of the Microstructure of 7A52 Aluminum Alloy Joints Welded by Friction Stir Welding". Materials 14, n. 21 (24 ottobre 2021): 6362. http://dx.doi.org/10.3390/ma14216362.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The microstructure and texture of materials significantly influence the mechanical properties and fracture behavior; the effect of microstructure in different zones of friction stir-welded joints of 7A52 aluminum alloy on fracture behavior was investigated in this paper. The microstructural characteristics of sections of the welded joints were tested using the electron backscattered diffraction (EBSD) technique. The results indicate that the fracture is located at the advancing side of the thermomechanically affected zone (AS-TMAZ) and the stir zone (SZ) interface. The AS-TMAZ microstructure is vastly different from the microstructure and texture of other areas. The grain orientation is disordered, and the grain shape is seriously deformed under the action of stirring force. The grain size grows unevenly under the input of friction heat, resulting in a large amount of recrystallization, and there is a significant difference in the Taylor factor between adjacent grains and the AS-TMAZ–SZ interface. On the contrary, there are fine and uniform equiaxed grains in the nugget zone, the microstructure is uniform, and the Taylor factor is small at adjacent grains. Therefore, the uneven transition of microstructure and texture in the AS-TMAZ and the SZ provide conditions for crack initiation, which become the weak point of mechanical properties.

44

Wang, Yong, Guangqiang Li, Chengyi Zhu, Xinbin Liu, Yulong Liu, Yang Gao e Yu Liu. "Micro Characterization of Hot-Rolled Plate of Nb-Bearing Grain-Oriented Silicon Steel". Materials 15, n. 2 (7 gennaio 2022): 429. http://dx.doi.org/10.3390/ma15020429.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

In this study, niobium was added into grain-oriented silicon steels, four Nb-bearing hot-rolled bands with Nb content range from 0–0.025 wt% were prepared and a detailed study of the micro characterization (microstructure, texture and precipitates) of hot-rolled bands was carried out by various analysis methods, such as EBSD and TEM. The results indicate that the precipitates in Nb-free steel are MnS and AlN; however, in the Nb-bearing steel they are MnS, AlN and Nb(C, N). The precipitates are finer and more dispersed in Nb-bearing steel, and a stronger pining force was obtained, which contributes to the finer microstructure and less recrystallization fractions of the hot-rolled bands. A larger volume fraction and stronger intensity of Goss texture is presented in steel with 0.025 wt% Nb due to the effective inhibiting effect. However, it has little effect on the changes of microstructure and texture when the Nb content is more than 0.009 wt%.

45

Adams, W. W., D. Yang e E. L. Thomas. "Direct visualization of microstructure deformation processes in polyethylene". Proceedings, annual meeting, Electron Microscopy Society of America 45 (agosto 1987): 456–59. http://dx.doi.org/10.1017/s0424820100127001.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Deformation processes of semicrystalline polymers are highly dependent on microstructure and its orientation, as for example in the different zones of spherulites. The elucidation of the deformation mechanisms is a complex problem, primarily due to the hierarchy of structural features present. Our approach to the determination of the important morphological processes occuring during deformation is to simplify both the sample morphology and the applied stress. The production of near single-crystal texture thin polyethylene (PE) film was made possible by modification of Petermann's method to prepare highly chain axis oriented and planar textured films of high density (HD) PE, in both as-drawn (AD) and annealed (AN) forms. These single crystal texture films were ideal for in situ microscopic deformation studies.HDPE (Marlex 6003 from Phillips Chemical) was melt-drawn from a glass slide at 120°C to form AD films, some of which were then annealed on glycerol at 128°C for two hours.

46

LI, Hong-ping, Ling-ying YE, Pan ZHANG, Jue ZHONG e Ming-hui HUANG. "Microstructure and texture characterization of superplastic Al-Mg-Li alloy". Transactions of Nonferrous Metals Society of China 24, n. 7 (luglio 2014): 2079–87. http://dx.doi.org/10.1016/s1003-6326(14)63315-x.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

47

Emadinia, Omid, Jorge Gil, Rui Amaral, Cláudia Lopes, Rui Rocha e Ana Reis. "Laser Deposited 18Ni300 Alloy Powder on 1045 Steel: Effect of Passes and Preheating on Microstructure". Materials 15, n. 3 (5 febbraio 2022): 1209. http://dx.doi.org/10.3390/ma15031209.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The application of maraging steels such as 18Ni300 alloy is noteworthy for mould industries, applying repair purposes through direct energy deposition process. This objective requires microstructural characterizations and the evaluation of mechanical behaviour such as hardness. The state of substrate material, including the heat-affected zone (HAZ) and the interface between the HAZ and deposited layer, is essential, the formation of hard phases and abrupt transitions. Thus, the influence of the number of deposited layers or the pre-heating condition appears noteworthy. In the current study, microscopy observations did not reveal the presence of any crack in the cross-sections of deposited 18Ni300 alloy powder on AISI 1045 sheet steel; however, pores were observed in deposited layers. Besides, microscopic analyses revealed the achievement of a smooth HAZ in the deposited layers composed of three-layered depositions or that received preheating, confirmed by hardness measurements as well. Dilution effect ensured a metallurgical bonding between depositions and substrate, strongly affected by preheating. The HAZ microstructure, mainly martensitic transformation, distribution of chemical composition, epitaxial growth at the interface, and the size of crystals and grains were affected by preheating or the number of layers. Moreover, the heat propagation and/or dissipation across the deposited layers influenced the dendrite morphology and the texture of grains. The preheating condition provoked the formation of cellular/equiaxed dendrites that was highlighted in the three-layered deposition, increase in dendrite interspace growth.

48

Low, It Meng, Wei Kong Pang e Ian J. Davies. "Mapping the Microstructure–Property Relationships in Cortical Bone". Key Engineering Materials 309-311 (maggio 2006): 523–26. http://dx.doi.org/10.4028/www.scientific.net/kem.309-311.523.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Structure-property relationships in bovine cortical bone have been characterised using grazing-incidence synchrotron radiation diffraction, Vickers indentation and mechanical testing. Depth profiling results indicated the existence of distinct gradual changes in crystal disorder, phase abundance, and texture of hydroxyapatite whilst the crystallite size was depth-independent.

49

Gong, Jian, Andrew Godfrey, Jiaji Ma e Ruifeng Li. "Investigation of microstructure and texture as related to primary recrystallization of grain-oriented silicon steel". Journal of Physics: Conference Series 2635, n. 1 (1 novembre 2023): 012009. http://dx.doi.org/10.1088/1742-6596/2635/1/012009.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Abstract Grain-oriented silicon steel requires a very strong Goss {110}<001> texture and as such a comprehensive control of thermo-mechanical processing parameters is required to achieve a strict control of texture. In particular the cold rolling and decarburization annealing process parameters have a determining effect on the grain size, the grain size distribution and the crystal texture distribution. In this study, the effect of cold rolling reduction on texture distribution in cold-rolled sheet has been analyzed. Secondary recrystallization of grain-oriented silicon steel is also highly dependent on the microstructure and texture after primary recrystallization. The influence of annealing temperature and carbides on the primary recrystallization process has also been investigated by measurements of grain growth and texture following primary recrystallization. By optimizing the microstructure and the texture of primary recrystallization of grain-oriented silicon steel, it is shown that a grain-oriented silicon steel exhibiting high magnetic induction low iron loss has been developed at Shougang Steel.

50

Raptopoulos, Luciano Santos Constantin, Gilberto Alexandre Castello-Branco, Cristiane Maria Basto Bacaltchuk, Iuliana Dragomir-Cernatescu e Hamid Garmestani. "Evolution and Prediction of Texture in Commercially Pure Warm Rolled Titanium". Materials Science Forum 758 (giugno 2013): 99–105. http://dx.doi.org/10.4028/www.scientific.net/msf.758.99.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Titanium alloys are used in a wide variety of aerospace, energy, industrial and biomedical applications, among other reasons, due to their superior properties. These properties are highly dependent of materials microstructure, i.e. texture, dislocation density and slip system activity. Therefore, in order to be able to design materials with certain properties it is crucial an understanding of the deformation process in terms of microstructural parameters. Microstructure evolution in warm rolled commercially pure titanium was investigated by means of X-ray diffraction and modeled with a crystal plasticity self-consistent scheme. Texture measurements and peak profile analysis were used to characterize the deformation texture and evaluate the relative activity of the various slips systems activated during the deformation process. The peak profile analysis data and the self-consistent predictions of texture evolution showed a good agreement with the experimental deformation texture evolution.

Articoli di riviste sul tema "Microstructure and crystal texture characterization"

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili