Compression Texture Research Articles

Activation of contraction twins during compression and related texture characteristics in α-titanium

This work demonstrates that axial compression along 0002and101¯0 in individual grains of α-Titanium can effectively activate up to six variants of 112¯2112¯3¯ contraction twins (CT). Compression parallel to 101¯0 primarily introduces 101¯2101¯1¯ type extension twins (ET), orienting the c-axis almost along the compression axis. Further compression activates up to six 112¯2112¯3¯ CT variants, each with a specific orientation having Euler angles of (0°−60°+n60°, 63.5°, 30°), where n is the sequence number of the CT variant. All six CT variants may not be activated during uniaxial compression due to the deviation of the parent grains' c-axis from the compression direction (CD) and deformation heterogeneities. The nucleation and interaction of CT variants lead to the formation of coincident site lattice boundaries with characteristics (θ−uvtw) angle axis pair of 63.5°101¯0−∑7b, 51.2°11¯00−∑23a, 60°112¯1−∑19b, and 77.3°18¯70−∑17b. The activation of multi CT variants and their interaction can contribute to grain fragmentation and texture weakening. From statistical analyses, the nucleation and growth of CT variants appeared to follow the Schmid law. However, deviations from the Schmid behavior occurred by the activation of low Schmid factor CT variants and could be attributed to slip and twin activities in neighbor grains.

A detailed study on the cooking kinetics of fresh and hard to cook common beans (Phaseolus vulgaris L.): A case study on bean accessions of different market classes

A large-scale study was conducted to obtain a more holistic understanding of the cooking behavior for different bean accessions in terms of cooking kinetics and time to cook. Fresh and aged soaked beans from twenty-four accessions were assessed for texture evolution during cooking at 95 °C using the most informative objective compression texture analysis method. Texture evolution was modelled by the conventional fractional conversion model as well as modified three-parameter models to capture the lag phase. The initial texture varied across bean accessions and is significantly positively related to bean size. Significant but limited differences in initial texture on ageing were observed, the difference being accession dependent. The texture evolution during cooking, cooking kinetics and time to cook varied across bean accessions and storage conditions and all bean accessions developed the hard to cook defect. The softening rate constants for fresh beans were significantly higher (0.026–0.053) and more variable than for aged beans (0.008–0.014, almost similar values). Fresh and aged beans of a given accession softened to similar levels of final relative hardness. The lag phase was more prominent in aged beans (up to ≈25 min) than non-aged beans (0–7 min). Therefore, the difference in time to cook for fresh beans across accessions is mainly determined by the difference in initial hardness and cooking rate constant, while for aged beans these differences depend on initial hardness and lag time and to a lesser extent on the cooking rate constant.

Real‐Time Neural Materials using Block‐Compressed Features

AbstractNeural materials typically consist of a collection of neural features along with a decoder network. The main challenge in integrating such models in real‐time rendering pipelines lies in the large size required to store their features in GPU memory and the complexity of evaluating the network efficiently. We present a neural material model whose features and decoder are specifically designed to be used in real‐time rendering pipelines. Our framework leverages hardware‐based block compression (BC) texture formats to store the learned features and trains the model to output the material information continuously in space and scale. To achieve this, we organize the features in a block‐based manner and emulate BC6 decompression during training, making it possible to export them as regular BC6 textures. This structure allows us to use high resolution features while maintaining a low memory footprint. Consequently, this enhances our model's overall capability, enabling the use of a lightweight and simple decoder architecture that can be evaluated directly in a shader. Furthermore, since the learned features can be decoded continuously, it allows for random uv sampling and smooth transition between scales without needing any subsequent filtering. As a result, our neural material has a small memory footprint, can be decoded extremely fast adding a minimal computational overhead to the rendering pipeline.

Dynamic Shear Texture Evolution during the Symmetric and Differential Speed Rolling of Al-Si-Mg Alloys Fabricated by Twin Roll Casting.

The effects of a reduction in area (RA) and the speed ratio between the top and bottom rolls on a shear strain and the crystallographic texture evolution of Al-Si-Mg (1.0%Si-0.6%Mg) aluminum alloys fabricated by twin roll casting (TRC) were comprehensively examined experimentally and through numerical predictions. Initial twin-roll casted strips had a texture gradient from the surface to the center. ⟨111⟩//ND textures were found in the surface layer, and weak rolling textures existed in the center of the strip. The distributions of shear and plane strain compression (PSC) textures varied with the RA and differential speed ratio. Strong shear textures including a rotated cube, {100}⟨011⟩, were obtained from both the symmetric and differential speed rolling processes. Symmetric rolling with a different reduction in area (SRDRA) produced shear textures mainly in the surface layer. Differential speed rolling (DSR) caused dynamic shear textures along the thickness direction, not limited to the surface. Based on the finite element method and crystal plasticity, the effects of different RA values, differential speed ratios, and friction coefficients on shear strain and texture evolution are discussed in detail. Loads measured from work rolls during DSR decreased with an increase in the speed ratio.

Compression Behavior and Textures of Ti57-Nb43 Alloy at High Temperatures.

The mechanical behavior, microstructures, as well as the crystallographic textures of the Ti57-Nb43 alloy were investigated on cylindrical specimens compressed at high temperatures, in the range of 700-1000 °C, and strain rates between 0.001 and 1.0 s-1. Hardening, followed by softening behaviors, were observed as a function of strain due to the occurrence of dynamic recrystallization/recovery in hot deformation. The modified five-parameter Voce-type equation described well the stress-strain curves, but, for the present alloy, it was also possible with only four parameters. A new two-variables polynomial function was employed on the four parameters that described well the flow curves as a direct function of temperature and strain rate. It permitted the reduction in the number of parameters and had the predictive capacity for the flow stress at any temperature, strain, and strain rate in the investigated range. The crystallographic textures were similar at all temperatures, with an increase in intensity from 900 °C. The textures could be characterized by a double <100> and <111> fiber and a unique component of (001) <110>, the latter inherited from the initial hot-rolling texture. Viscoplastic polycrystal self-consistent deformation modeling reproduced the measured textures showing that dynamic recrystallization did not alter the development of the deformation texture, only increased its intensity.

Strain hardening rate and strain rate sensitivity behavior of bcc/fcc-dual-phase tungsten heavy alloy

90W-7Ni-3Fe alloy is a heterogeneous biphasic alloy, and it is essential to investigate the impact of the biphasic microstructure on key mechanical properties at varying strain rates. To address this issue, the quasi-static and dynamic compressive mechanical properties of dual-phase 90W-7Ni-3Fe alloy, single-phase pure W, and single-phase NiFe alloy were comparatively analyzed in conjunction with characterization analysis. The results indicate that the flow stress, strain hardening rate (SHR), and strain rate sensitivity (SRS) of the 90W-7Ni-3Fe alloy at various strain rates are mainly due to the involvement of W particles during the initial strain, although the overall plastic deformation of the alloy is attributed to the continuous coordinated deformation of the W particles with γ-(Ni, Fe) phases in various regions. In addition, the compressed W phase shows a typical 〈111〉 and 〈100〉 BCC compression texture and the compressed γ-(Ni, Fe) phase shows a typical 〈110〉 FCC compression texture, both with high Schmidt factors. These characteristics are essential for slip transfer and strain transfer from the γ-(Ni, Fe) phase to the W phase. Notably, the increased number of slip systems at high strain rates makes them more susceptible to both types of transfer, resulting in higher flow stress, SHR, and SRS during initial deformation.

Quantitative texture analysis comparison of three legumes.

A validated texture-analysis method to evaluate product quality in frozen or cooked legumes is needed to support high-quality vegetable production but is not currently established in the literature. Peas, lima beans, and edamame were investigated in this study due to similar market use as well as growth in plant-based protein consumption in the United States. These three legumes were evaluated after three different processing treatments (blanch/freeze/thaw (BFT); BFT+microwave heat (BFT+M); BF+stove-top cooking (BF+C)), using both compression and puncture analysis following an American Society of Agricultural and Biological Engineers (ASABE) texture analysis method and moisture testing following an American Society for Testing and Materials (ASTM) standard method. Texture analysis results showed differences between legumes and processing methods. Compression analysis identified more differences between treatments within product type than puncture for both edamame and lima beans indicating compression might be more sensitive to texture changes in these products. Implementation of a standard texture method for legume vegetables for growers and producers would provide a consistent quality check to support efficient production of high-quality legumes. Due to the sensitivity obtained from the compression texture method in this work, compression should be considered for future research into a robust method to evaluate edamame and lima bean textures throughout the growing and production processes.

Evaluation and relationship analysis of pea protein on structure and heat-induced gel performance of myofibrillar protein.

Surimi products occupy a large market in the food industry, and the gel performance is an important index to evaluate them. Thus, it is of great significance and practical value to find better food ingredients to regulate the structure and gel performance of surimi products. In this study, we used pea protein (PP) to restructure fish myofibrillar proteins (MPs) to achieve regulation of protein gel performance. PP could enhance MP gel performance in terms of compressive strength, water-holding capacity, and some texture parameters. This may be the result of an increasing β-sheet content and a decreasing trend in the α-helix content, along with enhancements in hydrophobic interactions, nonspecific associations, and ionic bonds in a mixed PP-MP gel. The compressive strength, texture, and water-holding capacity of MP gel were positively correlated with surface hydrophobicity, active sulfhydryl, turbidity, and β-sheet of the mixed PP-MP system. The findings suggest that PP can regulate the gel performance by remodeling the structure of MP. The regulation and correlation analysis between gel performance, structure, and physicochemical properties were explored and established to provide a theoretical basis for improving the quality of surimi products. This study will broaden the application of PP in the field of food processing and provide theoretical guidance for the manufacture of new surimi products. © 2023 Society of Chemical Industry.

Effect of strain rate on the compressive strength and texture of maraging steel grade 250

The present study demonstrates the effect of strain rates (in terms of cross head velocities of 0.1, 0.5 and 1 mm/min) during uniaxial compression test of cold rolled and annealed maraging steel (grade 250) on microstructure, texture and mechanical properties. The texture developed at lowest (0.1 mm/min) and highest (1 mm/min) strain rate facilitates the grains of the microstructure to take the equiaxed shape and bring some degree of uniformity as compared to the grains of starting (cold rolled and annealed) material. At intermediate (0.5 mm/min) strain rate the grains reorient towards the starting texture which provides a similarity in the microstructure of this and starting materials. The hardness and compressive strength at 15% total true strain of the alloy increases with increase in strain rates during the compression test. The role of texture in strengthening of compressed samples deformed with different strain rates as compared to the starting sample has been explained by the near Goss recrystallization component ((111) [1-1 0 ]) which is present in the starting material and remains absent in all the compressed samples. The (111)-fibre formation is observed to be an important phenomenon in this alloy. The (111)-fibre is strengthened in the starting material and the material compressed with 0.5 mm/min. The intensity of (111)-fibre becomes weaker for the samples compressed with lowest (0.1 mm/min) and highest (1 mm/min) strain rates and results in improved microstructure of the alloy.

Effect of Y2O3 dispersoids on microstructure and creep properties of Hastelloy X processed by laser powder-bed fusion

• The effect of Y 2 O 3 dispersoids on microstructure and creep properties of Hastelloy X processed by LPBF is investigated. • Grains are found aligned along build direction, with a strong <001>Ni texture along both build and laser scanning directions. • LPBF Hastelloy X exhibits anisotropic creep response, with elongated grains showing higher creep resistance when aligned along loading direction than when aligned perpendicular to loading direction. • Y 2 O 3 dispersoids improve alloy creep resistance at dislocation-creep regime. • Alloy grain structure remains resistant to recrystallization during high-temperature solutionizing and creeping. Laser powder bed fusion (LPBF) was used to consolidate powders of a Ni-Cr-Fe-Mo alloy (Hastelloy X) blended with 1 wt% Y 2 O 3 nanometric powders. The nearly-dense, crack-free specimens, with and without oxide dispersion strengthening (ODS), exhibit high-aspect ratio grains, aligned in the build direction and with a strong texture: 〈001〉 is aligned along both build direction and laser scanning direction. Creep tests performed at 950 °C, with compressive stresses aligned with the elongated grains (and the build direction), reveal two creep regimes: (i) at stresses below ∼50 MPa, diffusional creep dominates, and the ODS alloy is less creep resistant than the non-ODS alloy, consistent with a somewhat smaller grain size resulting from grain-boundary pinning by the oxide dispersoids; (ii) at stresses above ∼50 MPa, dislocation creep dominates and the ODS alloy is more creep resistant, as expected from oxide dispersoids impeding dislocation motion. When tested perpendicular to the build direction, both alloys have the same creep resistance, which is however much lower than when the stress is aligned with the build direction, reflecting a strong effect of texture and grain shape. After ∼10% compressive creep deformation, grain structure and texture remain largely unchanged as compared to pre-creep structure.

Edge-Based Video Compression Texture Synthesis Using Generative Adversarial Network

It has been recognized that texture patterns with abundant high-frequency components, such as grass and water, produce visual masking effects, and the distortion in textures is hard to be perceived by human eyes than structure regions. However, modern video codecs in a rate-distortion optimized manner usually consume a lot of bits to encode textures, leading to the insufficiency in perceptual coding performance. Nowadays, with the rapid development of deep learning, learning based texture synthesis methods have been proposed to replace the coding process of prediction residuals to reduce the rate cost. In this paper, we present a deep texture synthesizer named edge-based texture synthesis framework (ETSF). At encoder side, the framework detects texture regions by semantic and fidelity classification criteria, and the detected regions are quantized coarsely by the hybrid coding framework. In texture characterization, ETSF extracts low-level edge features representing pixel intensity variation. Feature processing tools are developed to remove the spatiotemporal redundancy of edges. The processed edge information is compressed and transmitted. To effectively recover textures, we design an edge-based texture synthesis generative adversarial network (ETSGAN) at the decoder of ETSF, which can incorporate edge information into convolutional layers and generate realistic textures. Experimental results on a collected texture dataset show that the proposed ETSF can achieve an average of -12.8%, -14.2% and -9.6% MOS BD-rate under lowdelay_B, lowdelay_P and random_access configurations of VVC coding, respectively.

Effect of laser shock peening on tensile properties and microstructure of selective laser melted 316L stainless steel with different build directions

316L stainless steel tensile samples were fabricated via selective laser melting (SLM), wherein the build directions (BD) deviated from the tensile directions by 0°, 45°, and 90°. The effects of BD and laser shock peening (LSP) on compressive residual stress distribution, microstructure, texture, and tensile properties were investigated. The intensity and volume fraction of strong <110> fibre texture decreased after LSP, and the sample with a build angle of 90° had the weakest intensity and the least volume fraction. A tensile test was conducted at 25 °C temperature to investigate the effects of the BD and LSP on strength and ductility. LSP resulted in a noticeable improvement in the strength of all the samples, but the ductility of the samples with 0° and 45° build angles declined. Additionally, it was found that 316L fabricated via SLM with a build angle of 90° and subjected to LSP had the optimal combination of strength and ductility.

PSNR 값 기반의자동화된 ASTC 블록 크기 결정 방법

ASTC is one of the standard texture formats supported in OpenGL ES 3.2 and Vulkan 1.0 (and later versions), and it has been increasingly used on mobile platforms (Android and iOS). ASTC’s most important feature is the block size configuration, thereby providing a trade-off between compression quality and rates. With the higher number of textures, however, it is difficult to manually determine the optimal block sizes of each texture. To solve the problem, we present a new approach based on PSNR values to automatically determine the ASTC block size. A brute-force approach, which compresses a texture on all block sizes and compares the PSNR values of the compressed textures, can increase the compression time by up to 14 times. In contrast, our three-step approach minimizes the compression-time overhead. According to our experiments on a texture set including 64 various textures, our method determined the block sizes from 4x4 to 12x12 and reduced the size of compressed files by 68%.

Microstructural origin and control mechanism of the mixed grain structure in Ni-based superalloys

Mixed grain structure, as an incomplete recrystallization, should be homogenized and refined by subsequent processing to improve the mechanical properties of the aeroengine components. The microstructural origin and control mechanism is quite necessary for the microstructure homogenizing and grain refining through thermo-mechanical processing. In present research, microstructural origin and control mechanism of the mixed grain structure have been conducted deeply. With the consideration of temperature drop in practical industrial forging, the optimum processing parameters can be determined as 1110–1140 °C/1.0 s−1 to obtain homogeneous equiaxed grains. The microstructure evolution corresponding to the identified optimal parameters, viz., deformation temperature and strain rate, were systematically investigated. Higher dynamic recrystallization (DRX) fraction and coarser DRX grains can be observed at super-solvus temperature deformation (1140 °C). In addition, sub-solvus deformation (1110 °C) shows random orientated distribution while near< 001 > compression texture can be detected in super-solvus deformation. Particular attention was paid to the DRX mechanisms during hot deformation. Discontinuous dynamic recrystallization (DDRX) and continuous dynamic recrystallization (CDRX) occur simultaneously, and the synergistic effect of them contributes to microstructure control. Moreover, DDRX characterized by grain boundary bulging dominants the microstructure control. Progressive subgrain rotation labeled as CDRX can be regarded as an important assistant mechanism. The findings would provide theoretical support for microstructure control of Ni-based superalloys with mixed grain structure, which is of vital importance for components to obtain excellent performance.

Residual properties of steel slag coarse aggregate concrete after exposure to elevated temperatures

Steel slag, waste by-product during steelmaking process, has great potential in concrete production. Over the past few decades, extensive research studies were conducted on the mechanical behaviour and chemical property of concrete made with steel slag at ambient temperature. However, relatively little effort has been put to study the behaviour of concrete with steel slag after exposure to elevated temperatures. To fill up this research gap, an experimental study was conducted in which five concrete mixes with steel slag replacing natural coarse aggregate (crushed granite) were prepared. The effect of slag replacement ratio by volume (0%, 25%, 50%, 75% and 100%) on the heating behaviour, residual compressive strength, weight loss and surface texture of concrete under curing period of 28 and 91 days, after exposure to 25℃ (ambient temperature), 400℃, 600℃, 800℃ and 1000℃ was investigated. Besides, chemical deterioration behaviour was studied using X-ray diffraction analysis. From the test results, it is evident that with steel slag partially or totally replacing crushed granite, the heat insulation ability of concrete could be enhanced. Moreover, the residual strength of concrete with slag replacement ratio of 100% after exposure to elevated temperatures ≥600℃ would be comparable to concrete with crushed granite only. Lastly, the design model by EC2 was adopted to predict the residual strength of concrete with and without slag and results demonstrated that EC2 was conservative.

Geometrically necessary dislocation density evolution as a function of microstructure and strain rate

The role of microstructure and strain rate on the development of geometrically necessary dislocation (GND) density in polycrystalline copper subjected to compression is assessed via crystal plasticity modelling and electron microscopy. Micropolar crystal plasticity finite element (MP-CPFE) simulations show that GND density is strongly dependent on crystal orientation, with the highest values in grains with a <101> direction parallel to the compression axis. Experimental analysis shows that this relationship breaks down and demonstrates that orientation is only one of many microstructural features that contributes to dislocation density evolution. Texture development as a function of strain rate is also considered, and it is found that the commonly observed <101> compression texture is delocalized from that pole at high strain rate. Furthermore, quantitative analysis of the role of grain boundaries in GND density evolution highlights their role as strong dislocation sources.

Microstructure and Texture Evolution of Repetitive Upsetting-Extruded (RUEed) Mg-Gd-Y-Zn-Zr Alloy after Hot Compression

In order to determine the deformation temperature of next pass, the hot compression tests were performed by Gleeble-3800 at different temperature form 380 to 420 °C. The microstructure and texture evolution of repetitive upsetting-extruded (RUEed) Mg-Gd-Y-Zn-Zr alloy during hot compression were studied by electron backscattering diffraction (EBSD) analysis. The results showed that the dynamic recrystallization (DRX) occured during the hot compression processing from the strain-stress flow curves. When the temperature increased to 420 °C, the average grain size reduced to 6.64 μm, and the volume fraction of DRXed grains increased to 81.5%. All the compressed alloys exhibited a typical compression texture, the maximum texture intensity of {0001} plane gradually decreased with increasing temperature. When the compression temperature was up to 420°C, the the maximum texture intensity of {0001} plane was 3.207 due to the effect of DRXed grains. Finally, 420°C is chosen as the next deformation of next pass because of the more precipitation and DRXed grains.

Effects of temperature and strain rate on the tension-compression asymmetric plastic deformation behavior of ME20M magnesium alloy: Experiments and modeling

The tension-compression asymmetry of a rare-earth-containing alloy sheet, ME20M, is experimentally investigated along the rolling direction over a wide strain-rate range from 0.001 to 2500 s−1 and at temperatures from 213 to 488 K. The asymmetry of yield stress in tension and compression decreases with increasing temperature and decreasing strain rate. The strain-rate sensitivity of the tension-compression asymmetry during the plastic deformation stage increases with increasing temperature. It is observed that the compressive strain-hardening rate is much higher than the tensile one due to more {101-2} tension twins occurring in the compressive plastic deformation. A viscoplastic self-consistent (VPSC) model is employed to simulate the tensile and compressive stress-strain responses, deformation texture, and deformation mechanism evolution over wide ranges of strain rates and temperatures. Results indicate that the VPSC model is capable of capturing the macroscopic plastic deformation characteristics of ME20M alloy. Tensile plastic deformation is dominated by slip at strain rates up to 103 s−1, and basal slip and tension twinning are the main deformation modes in compressive plastic deformation. Effects of strain rate and temperature on the main plastic deformation mechanism of ME20M alloy are insignificant within the tested rate and temperature ranges.

Assessing the creep performance of full-scale bamboo scrimber columns

Bamboo scrimber is a kind of artificial processing material with high compressive strength, large size, natural texture, and wide application. It is made by rolling and de-fibering bamboo into a loose reticulate bundle, which is unbroken transversely, and loosely interlaced in the longitudinal direction, followed by drying, gluing, assembling, and hot pressing. In this study, to better understand the application value of bamboo scrimber in construction engineering, the performance of axially compressed solid columns that have been completed with three full-scale solid bamboo scrimber columns of 100 mm width, 100 mm height, and 2000 mm length were subjected to creep tests for 3 months. The specimens J1, J2, and J3 were designed to carry the long-term load of 0.2, 0.4, and 0.6 times the short-term test failure load of the same batch of specimens, respectively. The experimental study found that the bamboo scrimber columns could not bear 0.6 times of the short-term test failure load Pu, and that temperature and humidity greatly influenced creep of the specimens. Finally, a creep constitutive equation was established using a three-parameter model, and the equation matched well with the creep test data.

Influence of water loss on mechanical properties of stored blueberries

Moisture loss is considered a main cause of blueberry softening during postharvest storage. However, the causal relationship between softening and water loss has only previously been described by force to 1 mm compression. This study was performed to identify suitable instrumental tests that allow the separation of blueberries with different water loss values during storage. Mechanical properties were measured by double compression (Texture Profile Analysis) and puncture test. Variability on blueberry mechanical properties was created by regulating storage humidity and consequently water loss. As water loss increases during storage, hardness slope (slope of a straight line drawn between the trigger force of 0.06 N and the force at 15 % strain) obtained by the compression test reduces, and the displacement at berry skin break obtained by puncture test, increases. Therefore, these parameters can be potentially used to quantify mechanical changes in stored blueberries.