Textured Samples Research Articles

Mechanism of microstructure and texture evolution during hot rolling of pure Mg and Mg-0.2%Ce alloy

ABSTRACT The extruded samples of pure Mg and Mg-0.2%Ce alloy were subjected to a 90% reduction in thickness at 250°C during hot rolling. The microstructure, texture, and mechanical properties of the hot-rolled samples were evaluated. The microstructural evolution shows the presence of shear bands in Mg-0.2%Ce alloy at an angle of 30-35° concerning the normal direction and no such bands are observed in pure Mg. Upon annealing the samples at 400°C for one hour, it is observed that the grain size of Mg-0.2%Ce is smaller than pure Mg indicating that the precipitates of Ce arrest grain boundary mobility. The ex-situ EBSD microstructure analysis results show a higher change in the value of α33 components after annealing for pure Mg compared to Mg-0.2%Ce alloy suggesting the precipitates of Mg12Ce stabilises the pyr. <c + a > dislocations. The basal texture is observed in both samples after hot rolling. The experimental texture was simulated using the visco-plastic self-consistent (VPSC) modelling where it is observed that the initial extruded texture is favourable for the higher activity of pyr. <c + a > dislocation and extension twinning in Mg-0.2% e alloy. Further, the yield locus shows that Mg-0.2%Ce alloy shows relatively lower anisotropy compared to pure Mg. The yield strength and UTS of the pure Mg are higher than the Mg-0.2%Ce alloy which is attributed to the relatively more dislocation-dislocation interaction in pure Mg compared to Mg-0.2%Ce alloy resulting in the lower mean free path of the dislocations in pure Mg.

Estimation, Spatiotemporal Dynamics, and Driving Factors of Grassland Biomass Carbon Storage Based on Machine Learning Methods: A Case Study of the Hulunbuir Grassland

Precisely estimating the grassland biomass carbon storage is vital for evaluating grassland carbon sequestration potential and the monitoring and management of grassland resources. With the increasing intensity of climate change (CC) and human activities (HA), it is necessary to explore spatiotemporal variations in biomass carbon storage and its response to CC and HA. In this study, we focused on the Hulunbuir Grassland, utilizing sample plots data, MODIS data, environmental factors (terrain, soil, and climate), location factor, and texture characteristics to assess the performance of four machine learning algorithms: random forest, support vector machine, gradient boosting decision tree, and extreme gradient boosting in estimating grassland aboveground biomass (AGB). Based on the optimal model combined with root-shoot ratio data, grassland distribution data, and carbon content coefficients, the spatiotemporal characteristics and driving factors of biomass carbon storage from 2001–2022 were analyzed. The results showed that (1) the random forest achieved the highest prediction accuracy for grassland AGB, making it appropriate for AGB estimation in the Hulunbuir Grassland. (2) The spectral indices were the key variables of the grassland AGB, especially the enhanced vegetation index and difference vegetation index. (3) The 22-year average total biomass (TB) of the study area was 1037.10 gC/m2, of which the 22-year average AGB was 48.73 gC/m2 and 22-year average belowground biomass was 988.37 gC/m2, showing a spatial distribution feature of gradual increase from west to east. (4) From 2001–2022, TB carbon storage showed an insignificant growth trend (p &gt; 0.05). The 22-year average carbon storage of TB was 72.34 ± 18.07 gC. (5) Climate factors were the main driving factors for the spatial pattern of grassland TB carbon density, while the combined effects of CC and HA were the main contributors to the interannual increase in grassland TB carbon density.

Study on the surface performance strengthening of AlCrN coated cemented carbide by micro-texture laser preparation process

The combined application of coating and surface texture technology on the material surface can enhance its performance. However, the two procedure and their joint mechanism have not been fully revealed. Therefore, this paper takes the micro-textured coated cemented carbide as the research object, and focuses on the influence of preparation procedure and process parameters on surface characteristics and friction behavior. The results show that compared with the coating textured (XT) sample, the textured coating (XW) sample has more advantages in micro-hardness, microstructure and wear degree. The Rockwell hardness of the XT sample is better. Compared with the single coating sample, the coating micro-hardness of the XW sample is increased by 10 %, the Rockwell hardness is reduced by 2 %, the average grain size is reduced by 7.9 %, and the friction force is reduced by 6.2 %. Additionally, within a certain range, the increase of Al content will increase the sample hardness, reduce friction, and inhibit the Cr content and the growth of CrN phase grains. Complete process parameter optimization based on the ideal solution.

Towards end-to-end structure determination from x-ray diffraction data using deep learning

Powder crystallography is the experimental science of determining the structure of molecules provided in crystalline-powder form, by analyzing their x-ray diffraction (XRD) patterns. Since many materials are readily available as crystalline powder, powder crystallography is of growing usefulness to many fields. However, powder crystallography does not have an analytically known solution, and therefore the structural inference typically involves a laborious process of iterative design, structural refinement, and domain knowledge of skilled experts. A key obstacle to fully automating the inference process computationally has been formulating the problem in an end-to-end quantitative form that is suitable for machine learning, while capturing the ambiguities around molecule orientation, symmetries, and reconstruction resolution. Here we present an ML approach for structure determination from powder diffraction data. It works by estimating the electron density in a unit cell using a variational coordinate-based deep neural network. We demonstrate the approach on computed powder x-ray diffraction (PXRD), along with partial chemical composition information, as input. When evaluated on theoretically simulated data for the cubic and trigonal crystal systems, the system achieves up to 93.4% average similarity (as measured by structural similarity index) with the ground truth on unseen materials, both with known and partially-known chemical composition information, showing great promise for successful structure solution even from degraded and incomplete input data. The approach does not presuppose a crystalline structure and the approach are readily extended to other situations such as nanomaterials and textured samples, paving the way to reconstruction of yet unresolved nanostructures.

An innovative process chain for the production of antibiofouling polymer parts using ultrafast laser texturing

Polymers are versatile materials widely used in various industries, with significant applications in biomedicine where biofouling on polymer surfaces presents major health and economic challenges. Biofouling, initiated by bacterial adhesion, can be mitigated by modifying surface properties through laser micro- and nano-texturing, an approach that offers advantages over chemical treatments. This study introduces an economical mass production process for textured polymeric components using injection molding to replicate hierarchical textures. Testing revealed that all textured samples significantly reduced bacterial adhesion compared to untextured surfaces across different designs and bacteria types after 24 h of culture. The study examined factors like wettability, nanoscale roughness, and pattern dimensions to explain these outcomes, comparing them with existing studies. Despite all textured samples showing decreased wettability and roughness, these factors alone did not ensure reduced bacterial adhesion. The most effective anti-adhesive performance was observed in surfaces with parallel ridge patterns, which segmented the surface into isolated areas that limited bacterial interaction and hindered micro-colony formation, highlighting the importance of specific surface patterning in combating biofouling.

Enhanced Scratch Detection for Textured Materials Based on Optimized Photometric Stereo Vision and Fast Fourier Transform–Gabor Filtering

In the process of scratch defect detection in textured materials, there are often problems of low efficiency in traditional manual detection, large errors in machine vision, and difficulty in distinguishing defective scratches from the background texture. In order to solve these problems, we developed an enhanced scratch defect detection system for textured materials based on optimized photometric stereo vision and FFT-Gabor filtering. We designed and optimized a novel hemispherical image acquisition device that allows for selective lighting angles. This device integrates images captured under multiple light sources to obtain richer surface gradient information for textured materials, overcoming issues caused by high reflections or dark shadows under a single light source angle. At the same time, for the textured material, scratches and a textured background are difficult to distinguish; therefore, we introduced a Gabor filter-based convolution kernel, leveraging the fast Fourier transform (FFT), to perform convolution operations and spatial domain phase subtraction. This process effectively enhances the defect information while suppressing the textured background. The effectiveness and superiority of the proposed method were validated through material applicability experiments and comparative method evaluations using a variety of textured material samples. The results demonstrated a stable scratch capture success rate of 100% and a recognition detection success rate of 98.43% ± 1.0%.

The impact of pulsed Nd:YAG laser on the surface of n-Si and photo-electrical performance of silicon solar cells

Texturizing the surface of a silicon solar cell enhances performance by reducing reflection losses. Pyramidal texturization via wet chemical etching is standard in manufacturing, while plasma etching is often used for vertical hole texturization. Laser texturization offers a chemical-free, user-friendly alternative to plasma etching. Infrared (IR) transmission studies indicate that laser-textured samples transmit more IR light through n-Si than normally textured samples, suggesting that vertical grooves from laser texturization allow deeper light penetration. Analyses using cross-sectional Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersion x-ray (EDX), and Energy Dispersive Spectroscopy (EDS) demonstrate the effects of laser texturization on the front surface of textured n-Si wafers. However, silicon solar cells with laser-textured surfaces demonstrated lower conversion efficiencies (1.20% to 4.30%) compared to conventionally textured cells (14.30%). The short-circuit current density (JSC) was also lower in laser-textured cells, below 17 mA cm−2, compared to 34.44 mA cm−2 in normally textured cells. At the same time, higher laser power (114 W) during texturization also led to the lowest JSC and open-circuit voltage (VOC), indicating that laser texturization may introduce defects and dislocations that degrade Si properties.

Fabrication of superhydrophobic titanium surfaces: impact of different micropatterns

ABSTRACT Offshore and nuclear power plants use titanium condensers to cool exhaust steam from turbines. Preparation of robust superhydrophobic Titanium surfaces is necessary to protect these condensers from fouling and pitting phenomena. This study investigates the impact of various laser-textured Titanium grade 2 surface configurations followed by silicone oil heat treatment on enhancing its wettability and tribological properties. Seven distinct micropatterns were fabricated using a fiber laser with a laser power of 7.5 W, a scanning speed of 300 mm/s, a scan loop of 10, and a pulse frequency of 20 kHz. Patterned surfaces were characterized using different techniques, namely, micro-hardness, surface morphology, wettability, elemental analysis and wear. Improvement in wetting property was observed in laser textured samples after heating with silicone oil due to the adsorption of nonpolar groups (C=O, –CH3) resulting in a low energy surface. The grid pattern surface exhibited the highest water contact angle (WCA) of 151.01° due to a dense microstructure.

Carbon quantum dots derived from rice straw doped with N and S and its nanocomposites with hydroxypropyl cellulose nanocomposite

As biomass, rice straw (RS) is often valorized as a precursor of green products. In this respect, the RS-based carbon quantum dots (CQDs) are synthesized doped with N and S during the preparation. Synergistic doping with lipoic acid and ethylenediamine can vastly increase the yield of CQD from rice straw from 6.14 % to 62.8 %, and sulfur doping plays a more important role on the surface functional groups of the quantum dots. Further assessment is achieved toward the performance of SN-CQDs-hydroxypropyl cellulose nanocomposites. The optical behavior of synthesized SN-CQDs, and the critical concentration of its liquid crystal behaviors, at which the anisotropic phase begins to emerge, is approximately 1 %. Incorporating it into HPC, especially at 5 %, provided nanocomposite films with effective liquid crystal, tensile strength, and thermal stability. This sample's texture reveals a planar structure with colors ranging from yellow to red. The synergistic effect of incorporating SN-CQDs is shown by improving the strength to ~282.1 %, and the activation energy increased from 583.6 kJ.mol−1 to 615.1 kJ/mol. HPC-SN-CQDs can be assembled into an LED device, emitting warm light, of which CIE coordinate is (0.34,0.43).

Influence of bionic texture on the mechanical properties of 6061Al/CFRTP laser joints

Joining carbon fiber reinforced thermoplastic composites (CFRTP) with metals is a significant challenge for lightweighting in the automotive sector. The lower strength of hybrid joints limits their applications in the relevant fields. In this study, three distinct surface textures were applied to 6061 aluminum alloy (6061Al), including a traditional groove texture and two novel bionic textures (shark skin and fish scale), to enhance the strength of the hybrid joint between the materials. The impact of these textures on the mechanical properties of 6061Al/CFRTP hybrid joints was investigated through experimental methods and finite element simulations. The results indicated that the stress distribution at the interface of the bionic textured samples was more uniform, reducing stress concentration at the interface. Furthermore, the hybrid joint strength was improved as the bionic texture hindered crack initiation and propagation and facilitated crack deflection. Compared to the untextured samples, the fish scale textured samples exhibited the highest strength, which increased by 431.3 % relative to the untextured samples.

Neuronal and Behavioral Responses to Naturalistic Texture Images in Macaque Monkeys.

The visual world is richly adorned with texture, which can serve to delineate important elements of natural scenes. In anesthetized macaque monkeys, selectivity for the statistical features of natural texture is weak in V1, but substantial in V2, suggesting that neuronal activity in V2 might directly support texture perception. To test this, we investigated the relation between single cell activity in macaque V1 and V2 and simultaneously measured behavioral judgments of texture. We generated stimuli along a continuum between naturalistic texture and phase-randomized noise and trained two macaque monkeys to judge whether a sample texture more closely resembled one or the other extreme. Analysis of responses revealed that individual V1 and V2 neurons carried much less information about texture naturalness than behavioral reports. However, the sensitivity of V2 neurons, especially those preferring naturalistic textures, was significantly closer to that of behavior compared with V1. The firing of both V1 and V2 neurons predicted perceptual choices in response to repeated presentations of the same ambiguous stimulus in one monkey, despite low individual neural sensitivity. However, neither population predicted choice in the second monkey. We conclude that neural responses supporting texture perception likely continue to develop downstream of V2. Further, combined with neural data recorded while the same two monkeys performed an orientation discrimination task, our results demonstrate that choice-correlated neural activity in early sensory cortex is unstable across observers and tasks, untethered from neuronal sensitivity, and therefore unlikely to directly reflect the formation of perceptual decisions.

Unravelling the nexus between structure, texture, and acoustic traits of fried chicken nuggets

SummaryTexture is a multi‐parameter attribute and one of the prime quality attributes of fried products. This study explored the nexus between microstructure and texture of fried breaded chicken nuggets. Chicken nuggets were deep‐fat fried (2, 4, 6, and 8 min) in canola oil at different frying temperature (170, 180, and 190 °C). Microstructure and texture of fried samples were assessed by scanning electron microscopy (SEM) and acoustic‐mechanical texture analyser, respectively. Maximum force (Fmax), number of force peaks (NFP), area under force‐deformation plots (FA), sound pressure level (SPL), number of sound peaks (AUX), and area under amplitude‐time curves (SA) were used to describe the textural parameters. Microstructural indices (porosity, number of pores, average pore area, polydispersity index, and average shape factor) were estimated from the SEM images. Results revealed that, both the frying time and temperature were positively correlated with the mechanical (Fmax: 25–55 N, NFP: 05–74 N, FA: 6500–15 000 N.sec) and acoustic (SPL: 88–97 dB, AUX: 650–810 dB, SA: 380–405 dB.sec) parameters. Frying time and temperature significantly (P &lt; 0.05) impacted the formation of micropores in fried chicken nuggets. Crust microporosity showed strong positive correlations (r = 0.82) with the AUX value. The NFP, SPL, and SA of the fried nuggets were significantly (P &lt; 0.05) impacted by the crust microporosity. Crust porosity (10–30%), number of pores (8–400), average pore area (10–4000 μm2), polydispersity index (0.05–0.2), and average shape factor (0.8–1.1) of fried nuggets were significantly (P &lt; 0.05) influenced by both the frying time and temperature. Findings from this study would be useful in quality improvement and process monitoring including modelling of coated fried products.

Effects of preexisting dislocations on phase transition and deformation of NiTi shape memory alloy: An in situ multi-scale study

Phase transition and deformation in cold-rolled and heat-treated Ni50.6Ti49.4 alloys are explored by in situ multi-scale measurements with simultaneous X-ray diffraction and optical digital image correlation. Macroscale stress−strain curves, mesoscale strain fields and microscale X-ray diffraction peaks are obtained. Electron backscatter diffraction and transmission electron microscopy are also conducted on samples before and after tension as complements. For cold-rolled samples, since martensite nucleation is strongly associated with the widely distributed preexisting dislocations, homogeneous martensite phase transition takes place, in contrast with the localized mode in heat-treated samples. For localized phase transition, the intense growth of martensite results in clear Lüders bands. The beginning and the end of phase transition plateau on the stress−strain curve are associated with the initiation and complete propagation of Lüders bands. For the homogeneous phase transition, broad growth of martensite leads obscure Lüders bands and uniform strain fields, without any phase transition plateau. Given the initial {110}〈110〉 and {111}〈110〉 sheet textures in the heat-treated samples, different martensite variants with different preferred orientations are activated with respect to the loading directions.

Influence of various corn syrup types on the quality and sensory properties of gelatin-based jelly confectionery

Jelly candies are soft confectionery products primarily composed of sucrose, corn syrup and gelling agents. This study investigates the impact of six different corn syrup, all used at constant amount (46.22%), on the physicochemical (moisture content, pH, Colour), texture and sensory properties of gelatin-based jelly samples. The Moisture content, pH, colour, and texture properties of samples were analysed at 0th, 15th, 30th, 45th, and 60th day during storage. Before storage moisture content of the candiesranged from21.03 to 22.57% whereas after 60 days, it was found between 19.31 and 20.72%. Sample JF42 exhibited the least moisture rate loss. The type of corn syrup did not significantly affect the pH of the samples. Samples with higher fructose content in the corn syrup had the lowest hardness, whereas the sample with the highest maltose content exhibited the highest hardness. Changes in gumminess and chewiness paralleled variations in hardness results. Hardness and gumminess were found suitable to follow up gelatin-based samples storage using the zero-order kinetics modelling. Corn syrups with high fructose amounts intensified the redness, while those with high glucose levels led to yellowness in the candies. In sensory evaluation, products made with G40, G60, and M50 corn syrups received higher general Understanding how various types of corn syrup impact the candies quality helps producers optimize their formulation. This information enables producers to mitigate quality deterioration during storage, ensuring that their candies maintain at the desired level and appeal to consumers.

Influences of Surface Texture on the Friction Characteristics of Powder Metallurgy Clutch Disks

Many studies have consistently demonstrated the positive effects of surface texture on the performance of friction couples. Circular dimple textures are made on the flat surfaces of the copper-based powder metallurgy friction disk samples from a multi-disk clutch with five different circular densities. Long-term pin-on-disk sliding experiments under different loads are conducted. Surface morphology analysis is also conducted to evaluate the wear characteristics of the sample disks. Results show that the working load does not significantly affect the coefficient of friction (COF) of the flat surface samples, but there exist significant differences of the COF at different radii with the same rotation speed. Compared with the flat surface samples, the textured samples have a 20–65% decrease of COF under light load conditions but have a more than 30% increase under heavy load conditions. Furthermore, the wear of the textured samples is substantially reduced by more than 19% and 40% respectively. Therefore, the circular dimple texture can significantly enhance the friction and wear performances of the copper-based powder metallurgy friction disks, especially under heavy load working conditions.

Tribological behaviour of laser textured Ti3AlV 2.5V alloy under simulated body fluid

The use of lasers to fabricate micro-textures on the surface of medical implants is an effective method to improve their bio-tribological properties. In the present study, three distinct configurations of micro-textures, namely, co-axial circles, hexagon, and line with varying spacing of 300 µm, 400 µm, and 500 µm, were fabricated on Ti3Al2.5V alloy using Nd:YAG fibre lasers. The influence of micro-textured geometries on microhardness, coefficient of friction (COF), and wear rate was estimated. The tribological properties of the polished and textured samples were investigated using a linear reciprocating tribometer against silicon nitride (Si3N4) balls under simulated body fluid (SBF) lubricant. Orthogonal results indicate that the co-axial circles with a spacing of 305 µm prove to be the most efficient in enhancing the tribological performance of textured surfaces. This configuration demonstrates a significant improvement, with a 33.62 % reduction in friction coefficient and a 61.81 % reduction in wear rate compared to polished samples. The decrease in spacing appears to enhance the anti-friction and anti-wear properties of the textured surfaces. The working mechanism behind the reduction in the friction coefficient and wear rate lies in the capacity of the textures to trap particles.

Effect of laser ablation over cavitation, slurry erosion, and surface properties of 86WC-10Co-4Cr based ceramic coating developed using HP-HVOLF

The manuscript presents a detailed study on WC-10Co-4Cr powder coatings applied via HP-HVOLF and subjected to laser ablation. FESEM analysis showed strong metallurgical bonding between the coating and SS410 substrate (≈75 MPa), crucial for durability. Despite the presence of cavities and pits, the coating's overall thickness remains consistent post-ablation, affirming stability. EDS mapping confirmed uniform elemental distribution, with well-bonded transition zones. Vickers hardness increased in laser-ablated samples (HV0.3 ≈ 1523) compared to unablated samples (HV0.3 ≈ 1344). Slurry and cavitation erosion analyses demonstrated superior resistance in laser-ablated samples due to higher microhardness and elevated static contact angles. Contact angle measurements indicated hydrophobicity in both un-textured and textured samples, with textured surfaces showing increased hydrophobicity.

Microstructures and mechanical properties of Co-based Elgiloy fabricated by wire arc additive manufacturing

Wire arc additive manufacturing (WAAM) has emerged as a promising method for additive manufacturing due to its high efficiency and cost-effectiveness. This study aimed to fabricate Co-based Elgiloy by WAAM based on cold metal transfer technology. An 18-layers thin alloy wall was prepared. The microstructure, texture and mechanical properties of the as-deposited samples were investigated. Results indicated that the prepared alloy had good formability and was composed of a single face center cubic structure. The tensile properties of the alloy exhibited anisotropy due to the large number of columnar grains growing along the building direction in the alloy. The tensile samples along the building direction exhibited lower yield strength but better elongation due to the columnar grain growth direction and the softening effect of the remelted zone.

Study on Effect of Surface Micro-Texture of Cemented Carbide on Tribological Properties of Bovine Cortical Bone.

In bone-milling surgical procedures, the intense friction between the tool and bone material often results in high cutting temperatures, leading to the thermal necrosis of bone cells. This paper aims to investigate the effect of micro-texture on the tribological properties of YG8 cemented carbide in contact with bone. The main objective is to guide the design of tool surface microstructures to reduce frictional heat generation. To minimize experimental consumables and save time, numerical simulations are first conducted to determine the optimal machining depth for the texture. Subsequently, micro-textures with different shapes and pitches are prepared on the surface of YG8 cemented carbide. These textured samples are paired with bovine cortical bone pins featuring various bone unit arrangements, and friction and wear tests are conducted under physiological saline lubrication. The experimental results indicate that the appropriate shape and pitch of the micro-texture can minimize the coefficient of friction. The parallel arrangement of bone units exhibits a lower coefficient of friction compared to the vertical arrangement. This study holds significant implications for the design and fabrication of future micro-texture milling cutters.

Effect of temperature on the rheological, textural, and sensory properties of butters from New Zealand market.

Texture and sensory studies at various temperatures are important in evaluating and improving the functionality of butter. While literature is scarce, we evaluated and compared the effect of temperature (5-25°C) on the texture, rheological and sensory properties of commercial butter samples (salted, unsalted, cultured, and spreadable) from the New Zealand market. In addition, the instrumental analyses were compared with the sensory evaluation, to understand the possibility of using instrumental analysis to evaluate consumer liking for different butters. Butter type, temperature, and their type-temperature interaction exhibited significant differences for all instrumental textural parameters. As expected, higher temperature produced softer butter that was more spreadable, liquid-like, less adhesive, less cohesive, had lower storage modulus (G') and lower loss modulus (G″) with the melting of milk fat crystals; however, the rate of change varied for the different butter samples. We have established meltability as the parameter for evaluating butter selection for different applications. The spreadable butter sample exhibited the lowest hardness and G', and highest spreadability (p < .05) at all temperatures, owing to its low solid fat content and the abundance of low-melting triglycerides. The cultured butter sample had the highest melting point, owing to compositional differences. The instrumental and sensory texture analyses were highly correlated, indicating the comparative effectiveness of both approaches for studying the effects of different temperatures on butter textural properties. Overall, our findings provide detailed reference to the dairy industry for butter manufacture, considering variation in fatty acid composition, texture analysis, rheology, and sensory analysis, over the range of storage/usage temperatures.