Textural Characterization Research Articles

Design, machining and characterization of the components required for the manufacture of a supercapacitor

One of the main European objectives is to promote the change of consumption towards renewable energies, which have shown a remarkable worldwide growth, the problem lies in the fact that the technologies used, which have been developed very rapidly during these years, do not have sufficiently advanced energy storage systems.The main objectives of this study have been the design and manufacture of supercapacitors that do not suffer corrosion processes and with higher performance.To this end, supercapacitor connectors have been designed and machined with different materials in order to find the one that best ensures the non-influence of corrosion processes and ensures correct parallelism. In addition, different carbonaceous materials have been tested for the manufacture and subsequent textural, chemical and morphological characterization of the different electrodes and, finally, charge/discharge and cyclic voltammetry tests have been carried out to analyze which parameters are key for the manufacture and improvement of the supercapacitors.The results showed that the proposed supercapacitor manufacturing methodology is highly recommended to avoid problems derived from poor assembly, reproducibility of results or problems due to the appearance of galvanic couples. Moreover, the electrodes tested showed very interesting results, as demonstrated by the voltammograms, the chronopotentiograms and the specific energy values, the latter showing that the capacitance exerts a notable influence on the energy values, with the PCO1000C/Graphite and PCO1000C/rGO samples showing the highest energy values.

Comparative phenomenological modeling of the overall adsorption rate of drugs onto activated carbon. The case of the chlorpheniramine

The adsorption of chlorpheniramine on a predominantly acid-granular activated carbon was studied using diffusional kinetic models. The experiments were performed on rotatory basket batch adsorbers at pH values of 4, 7 and 9 and temperatures of 25, 35 and 45 °C using the equilibrium concentration and uptake of each experiment to describe the equilibrium behavior. The textural characterization demonstrated a type IV N2 isotherm, indicating that the active carbon used combines micro and mesopores. The adsorption isotherms obtained presented Langmuir behavior with an average deviation of 3%. The diffusional modelling revealed that surface diffusion is the predominant intraparticle diffusion mechanism governing the adsorption process, with contributions to the total intraparticle diffusion being higher than 96% regardless of the radial position. However, these contributions decreased as low as 50% when Chlorpheniramine (CPM) uptake increased. The pH studies demonstrated that the surface diffusion coefficient increased as the pH increased due to a combination of stronger π stacking interactions and electrostatic interactions. Meanwhile the temperature study demonstrated an increase in surface diffusivity as the temperature increased due to the higher energy that the chlorpheniramine molecules gained due to the temperature increment.

Plasmonic Photocatalysts Based on Au Nanoparticles and WO3 for Visible Light-Induced Photocatalytic Activity

In this work, we report the application of Au/WO3 composite as a photocatalyst for the degradation of dyes under solar light irradiation. Au/WO3 nanocomposites were synthesized using an acid precipitation method followed by an impregnation/reduction at room temperature. Two composites were obtained by loading gold nanoparticles on two morphologies of nanostructured WO3, nanoplatelets (NP), and pseudospheres (PS). The elaboration parameters of the nanocomposites were optimized according to the gold mass percentage, the HAuCl4 precursor concentration, and the impregnation time. The structural, microstructural, and textural characterization were conducted using advanced techniques: XRD, SEM/TEM microscopies, and XPS and DRS spectroscopies. The optimal synthesis parameters are a 48 h impregnation of a five mass percentage of gold from a HAuCl4 precursor with a concentration of 10−3 mol·L−1. The obtained composites were formed with Au nanoparticles of 7 nm in size. The XRD analyses did not reveal any modification of the oxide supports structure after gold grafting, contrary to the sorption analyses, which evidenced a change in the state of the materials surface. XPS analysis revealed the reduction of W6+ ions into W5+, favoring the presence of oxygen vacancies. Furthermore, a localized surface plasmon resonance effect was observed in the composite at 540 nm. The photocatalysis results of several dye pollutants have shown a selective degradation efficiency depending on the charge of the polluting molecules, pH medium, and mass loading of the catalysts. At the native pH, the photocatalysis process is highly efficient on a cationic molecule, with a low adsorption capacity. Au/WO3 PS composite appears to be the most efficient, degrading almost the whole RhB and MB only in 60 min and 90 min, respectively, while, for the MO anionic dye, the degradation is more efficient in acidic medium (80%) than in basic medium (0%). Trap tests of the main active species were investigated and a photodecomposition mechanism is proposed.

High‐pressure methane storage on metal‐organic frameworks

AbstractMethane storage performance of a series of metal‐organic frameworks (MOFs) has been thoroughly examined over a wide pressure range up to 750 bar. Based on volumetric adsorption measurements, crystal structure and porous texture characterization, excess, total and working adsorption capacities, and heat of adsorption as functions of pressure have been evaluated. It has been found that the use of MOFs demonstrates a significant advantage in methane storage capacity over compressed gas, and the Gain can reach 300% to 400% depending on the pressure‐temperature operating conditions. However, the benefit of adsorption storage drops with increasing pressure. Even for the best MOF adsorbent, this methane storage method becomes technologically unreasonable above 280 bar. The data obtained allowed us to conclude that conventionally reported excess adsorption does not give a complete picture of the effectiveness of MOFs. Besides high specific surface area, optimal density of the skeleton and moderate heat of adsorption are required for the best storage performance.

Chemical, microbiological, textural, and sensory characteristics of pilot-scale Caciofiore cheese curdled with commercial Cynara cardunculus rennet and crude extracts from spontaneous and cultivated Onopordum tauricum

The aim of this study was the chemical, microbiological, textural, and sensory characterization of pilot-scale prototypes of an Italian ewe’s raw milk cheese (Caciofiore) curdled with commercial Cynara cardunculus rennet, used as a control, and crude extracts obtained from flowers of either spontaneous or cultivated Onopordum tauricum. Hence, the control and experimental cheese prototypes produced in two rounds of cheesemaking trials were assayed, at the end of their 60-day maturation, for the following features: pH, titratable acidity, dry matter, fat, total and soluble nitrogen (TN and SN, respectively), ash, salt, protein, lactose, viable plate counts and composition of the bacterial and fungal populations, color, texture, volatile organic compounds (VOCs), and olfactory attributes by sensory analysis (the latter for the sole prototypes curdled with the commercial rennet and the extract obtained from cultivated O. tauricum). The data overall collected showed a very low impact of the type of thistle rennet on the analyzed cheese traits, with significant differences being exclusively found for SN/TN%, titratable acidity, color, and adhesiveness. By contrast, a higher impact of the cheesemaking round was seen, with significant differences being observed for salt content, load of presumptive lactobacilli, thermophilic cocci, and Escherichia coli, and levels of the following VOCs: 2,3-butanedione, 2-pentanone, 1-butanol, 2-heptanone, 3-methyl-1-butanol, 2-heptanol, 2-nonanone, dimethyl trisulfide, 2-methyl propanoic acid, butanoic acid, and 3-methyl butanoic acid. Sensory analysis revealed a strong ewe’s cheese odor, accompanied by other olfactory notes, such as pungent, sour curd, sweet, and Parmesan cheese-like notes, in all the analysed cheese prototypes. Moreover, key odor active compounds, including butanoic acid, ethyl butanoate, 2,3-butanedione, 1-octen-3-one, and dimethyl trisulfide, were identified by GC-olfactometry analysis. Regarding the odor attributes as determined by sensory analysis, again the type of rennet had an almost negligible impact, with significant differences being only perceived for 1 or 2 out of 20 odor attributes, depending on the analytical conditions applied. Although some aspects deserve further investigation, the results herein collected confirm that O. tauricum can be regarded as an alternative source of thistle rennet for the manufacture of Caciofiore cheese, and more in general, Mediterranean ewe’s milk cheeses.

Robocasting of ordered mesoporous silica‐based monoliths: Rheological, textural, and mechanical characterization

AbstractHierarchically porous, high‐surface‐area silica materials are excellent candidates for multiple applications like catalysis and environmental remediation. Shaping these materials with additive manufacturing (AM) techniques, like robocasting, could enable their use with the benefit of on‐demand, customized shaping and maximizing performance. Herein, ordered mesoporous silica COK‐12 slurries were robocasted into monoliths, containing different ratios of uncalcined COK‐12 and sodium bentonite (0–25 wt.%). The rheology of the mixed slurries is characterized by lower flow indexes (0.69 vs. 0.32) and higher yield stresses (96 vs. 259 Pa) compared to pure COK‐12 ones. Monoliths were printed in woodpile structures and calcined at 600°C. Micro‐CT measurements showed a linear shrinkage of 25% after calcination. Mechanical characterization showed increased uniaxial strength (0.20 ± 0.07 to 1.0 ± 0.3 MPa) with increasing binder/solids ratio from 13 to 25%. The amorphous, mesoporous structure of COK‐12 was retained. The structures exhibited open porosities of 52 ± 4% and showed higher specific mesopore volumes, and increased average mesopore size (6 vs. 8 nm) compared to COK‐12. Small‐angle x‐ray scattering analysis revealed an increased lattice parameter (10.3 vs. 11.0 nm) and reduced wall thickness (3.1 nm vs. 4.1 nm) of the COK‐12 in the monoliths. These properties indicate suitability for their application as porous supports and adsorbents.

Lung CT stabilization with high-frequency non-invasive ventilation (HF-NIV) and breath-hold (BH) in lung nodule assessment by PET/CT

PurposeTo evaluate the effect of lung stabilization using high-frequency non-invasive ventilation (HF-NIV) and breath-hold (BH) techniques on lung nodule detection and texture assessment in PET/CT compared to a free-breathing (FB) standard lung CT acquisition in PET/CT.Materials and methodsSix patients aged 65 ± 7 years, addressed for initial assessment of at least one suspicious lung nodule with 18F-FDG PET/CT, underwent three consecutive lung PET/CT acquisitions with FB, HF-NIV and BH. Lung nodules were assessed on all three CT acquisitions of the PET/CT and characterized for any size, volume and solid/sub-solid nature.ResultsBH detected a significantly higher number of nodules (n = 422) compared to HF-NIV (n = 368) and FB (n = 191) (p < 0.001). The mean nodule size (mm) was 2.4 ± 2.1, 2.6 ± 1.9 and 3.2 ± 2.4 in BH, HF-NIV and FB, respectively, for long axis and 1.5 ± 1.3, 1.6 ± 1.2 and 2.1 ± 1.7 in BH, HF-NIV and FB, respectively, for short axis. Long- and short-axis diameters were significantly different between BH and FB (p < 0.001) and between HF-NIV and FB (p < 0.001 and p = 0.008), but not between BH and HF-NIV. A trend for higher volume was shown in FB compared to BH (p = 0.055) and HF-NIV (p = 0.068) without significant difference between BH and HF-NIV (p = 1). We found a significant difference in detectability of sub-solid nodules between the three acquisitions, with BH showing a higher number of sub-solid nodules (n = 128) compared to HF-NIV (n = 72) and FB (n = 44) (p = 0.002).ConclusionWe observed a higher detection rate of pulmonary nodules on CT under BH or HF-NIV conditions applied to PET/CT than with FB. BH and HF-NIV demonstrated comparable texture assessment and performed better than FB in assessing size and volume. BH showed a better performance for detecting sub-solid nodules compared to HF-NIV and FB. The addition of BH or HF-NIV to PET/CT can help improve the detection and texture characterization of lung nodules by CT, therefore improving the accuracy of oncological lung disease assessment. The ease of use of BH and its added value should prompt its use in routine practice.

Characterisation and analysis of the surface texture of injection-moulded automotive interior ABS and PP components

Interior automotive plastic components are often manufactured by injection moulding since this technique enables cost-efficient manufacturing, large design freedom, and easy integration of functions. However, to obtain a high-quality impression, it is important to produce components with uniformity in texture, colour, and gloss. Unfortunately, this is rather difficult since a large number of material and processing parameters affect the surface topography and thereby the texture, colour, and gloss. It is therefore important to improve the understanding of how different material and processing parameters affect the surface topography, and in the present study, the influence on surface topography of ABS (Acrylonitrile Butadiene Styrene) and PP (Polypropylene) by melt temperature, tool temperature, and injection speed is investigated by coherence scanning interferometry. Area scale analysis is used to identify the wavelengths of interest, and areal surface parameters are statistically screened to identify robust surface parameters that can be used to discriminate between the surfaces and quantify the influence on surface topography by different material and process variables. Results from the study suggest that tool temperature and injection speed have significant influence on certain surface parameters and, particularly, arithmetic mean height (Sa) and root mean square gradient (Sdq) by approximately 40%, core material volume (Vmc) by 35%, and core roughness depth (Sk) by 50%. These surface parameters are identified as significant and used to discriminate between the sample surfaces.

Surface Texture and Microstructural Characterization of Thin-Walled Ti6Al4V Part Processed Using Laser Powder Bed Fusion Technique: Effect of Build Direction

Abstract Objective: The current research investigates the surface texture and microstructural characterization of thin-walled Ti6Al4V along the build direction processed using laser powder bed fusion (LPBF) technology using an intra-comparison approach. Methodology: The two-dimensional and three-dimensional surface morphology and multi-scale surface roughness analysis of all Ti6Al4V samples were performed using an opto-digital microscope (with extended focus imaging coupled with high dynamic range imaging). Moreover, the scanning electron microscope, microhardness tester, and X-ray diffraction techniques were used to analyze the microstructural and microhardness values. Findings: (1) The lath thickness was relatively thicker in the LPBF-processed Ti6Al4V sample’s microstructure at central locations than in the top and bottom locations. (2) The areal surface roughness (Sa), Rk, and Sk values were relatively lower for the middle region than for the bottom and top regions of the thin-walled part, implying nonuniform surface topography along the build direction. (3) The middle region had a higher surface texture and texture amplitude symmetry periodicity than the top and bottom regions along the build direction. Value: Overall, the established methodology employed on the thin-walled Ti6Al4V part processed using LPBF technology enables the selection criteria of a suitable surface finishing process to achieve isotropic finish for practical industrial applications.

Effect of combined cold deformation and subsequent heat treatment on the microstructure, texture, mechanical properties and cementite spheroidization in AISI 1070 steel

In this study, the effects of thermomechanical heat treatments on two batches of commercial AISI 1070 steel were investigated. Both samples underwent cold rolling and annealing at 600 °C for 30 min, and their microstructure and crystallographic texture were analyzed using XRD, SEM observations, and EBSD measurements. Tensile testing was also conducted to evaluate the mechanical properties of the steels. The results showed that the lamella pearlitic microstructure of both samples was transformed into α-ferrite matrix with spheroidal cementite particles (Fe3C). Sample A exhibited a strong γ-fiber texture parallel to the rolling plane, with a typical cold-rolled texture and high anisotropic characterization dominated by (111)<uvw> orientation. Sample B, on the other hand, exhibited (111)[12¯1] and GOSS (110)<001> texture components with dominant (111) and (101) grain orientations along the rolling direction. While the yield stress and tensile strength were higher in sample A, sample B had better toughness and elongation properties, indicating that it was more ductile. These findings highlight the importance of controlling heat treatment processes to achieve desired microstructures and mechanical properties in steels and provide insights into the relationship between microstructure, crystallographic texture, and mechanical properties. The results of this research could be useful in optimizing the process and performance of steels in various industrial applications.

Outstanding performance of hierarchical alumina microspheres for boron removal in the presence of competing ions

Developing efficient materials for the removal of boron from aqueous solutions is becoming an important task to overcome boron pollution. Herein, we present hierarchical alumina microspheres (HAM) as an outstanding adsorbent, synthesized via a microwave-assisted co-precipitation method. The microstructure, morphology, and textural characterization of the HAM particles carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) revealed hollow γ-Al2O3 particles with a porous dandelion-like shape and an average size of 1.5 μm. The analysis of the adsorption data indicated that the adsorption was homogeneous in a single layer and that chemical adsorption was the controlling step in the process. The adsorption capacity obtained at an initial concentration of 800 mg·L−1 was 51.60 mg·g−1, and the theoretically calculated maximum adsorption capacity using the Langmuir model was 138.50 mg·g−1, which outperforms previously reported adsorbents. The determination of thermodynamic parameters indicated that the adsorption is an exothermic and non-spontaneous process. The XPS spectra of HAM after adsorption indicated the formation of Al-O-B bonds. Of particular interest for industrial applications, the HAM adsorbent showed excellent selectivity for boron in the presence of competing cations or anions and at different ionic strengths. In addition, HAM maintained a high adsorption capacity after five consecutive adsorption/desorption cycles. These findings highlight the potential of HAM as a highly microporous material for boron removal in real industrial applications.

Scale effects on surface texture characterisation of ultra-precision diamond milling

Surfaces with nanometric texture, machined by ultra-precision diamond milling (UPDM), have wide applications for their functionalities. Surface texture characterisation is crucial for their quality evaluation and it would vary in the measurement data processing under various scales, which is termed scale effects. However, the scale effects have not been comprehensively studied. In this work, we focus on the scale effects on surface texture characterisation of UPDM. Firstly, a series of experiments were conducted at different material removal rates to produce surfaces with nanometric texture. Secondly, a discrete wavelet transform (DWT)-based method was employed for surface filtering and surface texture parameters (Sa, Sq, and Sz) were evaluated according to ISO standards. Thirdly, power spectral density (PSD) analysis and surface filtering comparison were performed to realize a scale observation. Furthermore, the effects of the filtering scale, the sampling scale, and the subarea scale on surface texture characterisation were investigated. Finally, the results showed that surface topographies were governed by various machining factors which resulted in multi-scale topographical components. The PSD analysis enabled discrimination of the multi-scale topographical components to the underlying machining factors. The DWT-based method achieved a relatively small deviation (<4%) for surface filtering as compared to the zero-order Gaussian regression filter. The filtering scale affected the filtered topographical components and it visualised and differentiated those components with the machining mechanisms. The sampling scale determined the filtered components to yield an impact on the characterisation results and Sz was more sensitive to this effect than Sa and Sq. The subarea scale influenced the probability distributions and statistical values of surface texture parameters within its contained components and it indicated that the increased material removal rate resulted in a deterioration of surface uniformity.

Characterization of fibre texture in satin spar using wide-range reciprocal-space mapping

Characterization of fibre texture in satin spar using wide-range reciprocal-space mapping

Texture Characterization Fuzzy Logic-Based Model for Melanoma Diagnosis

Over the past two decades, the world has known a significant number of deaths from cancer. More specifically, melanoma which is considered the deadliest form of skin cancer causes a remarkable percentage of all cancer deaths. Therefore, the health and disease management community has exceedingly invested in creating efficient devices that help dermatologists to early evaluate and inspect a specific kind of skin disease. These systems use some measurable visual component describing the shape, color, and texture of skin diseases to recognize them and to specify their malignancy. In this article, a fuzzy logic-based model is introduced which characterizes statistical texture features. The fuzzy model is built to classify skin lesions into malignant and benign based on the characterization of statistical texture features. This method has been proven to yield reliable results compared to the machine learning-based model. Besides, it is more stable and unbiased in classifying skin lesions than machine learning models.

Carbon Materials Prepared from Invading Pelagic Sargassum for Supercapacitors' Electrodes.

Since 2011, substantial amounts of pelagic Sargassum algae have washed up along the Caribbean beaches and the Gulf of Mexico, leading to negative impacts on the economy and the environment of those areas. Hence, it is now crucial to develop strategies to mitigate this problem while valorizing such invasive biomass. This work deals with the successful exploitation of this pelagic Sargassum seaweed for the fabrication of carbon materials that can be used as electrodes for supercapacitors. Pelagic Sargassum precursors were simply pyrolyzed at temperatures varying from 600 to 900 °C. The resultant carbonaceous materials were then extensively characterized using different techniques, such as nitrogen adsorption for textural characterization, as well as X-ray photoelectron (XPS), Fourier transform infrared spectroscopies (FT-IR) and scanning electron microscopy (SEM), to understand their structures and functionalities. The electrochemical properties of the carbon materials were also tested for their performance as supercapacitors using cyclic voltammetry (CV), the galvanostatic method and electrochemical impedance spectroscopy analyses (EIS). We managed to have a large specific surface, i.e., 1664 m2 g-1 for biochar prepared at 800 °C (CS800). Eventually, CS800 turned out to exhibit the highest capacitance (96 F g-1) over the four samples, along with the highest specific surface (1664 m2 g-1), with specific resistance of about 0.07 Ω g -1.

Multi-scale and multi-modal imaging study of mantle xenoliths and petrological implications

Abstract The accurate textural characterization of mantle xenoliths is one of the fundamental steps to understanding the main processes occurring in the upper mantle, such as sub-solidus recrystallization, magmatic crystallization, and metasomatism. Texture, composition, and mineralogy reflect the temperature, pressure, stress conditions, melting, and/or contamination events undergone before and during the entrapment in the host magma. For these reasons, characterizing the three-dimensional (3D) texture of silicate, oxide, sulfide, and glass phases has great importance in the study of mantle xenoliths. We performed a multi-scale and multi-modal 3D textural analysis based on X-ray computed microtomography (µ-CT) data of three mantle xenoliths from different geodynamic settings (i.e., mobile belt zone, pericraton, oceanic hotspot). The samples were selected to represent different, variably complex internal structures composed of grains of different phases, fractures, voids, and fluid inclusions of different sizes. We used an approach structured in increasing steps of spatial and contrast resolution, starting with in-house X-ray µ-CT imaging (spatial resolution from 30 µm down to 6.25 µm) and moving to high-resolution synchrotron X-ray µ-CT at the micrometer scale. We performed a 3D characterization of mantle xenoliths, comparing the results with the analysis of conventional 2D images (thin sections) obtained by optical microscopy and simulating the random sectioning of several thin sections to estimate the probability of correct modal classification. The 3D models allow the extraction of textural information that cannot be quantified solely from thin sections: spinel layering, distribution of silicic glass, and related vesicles. Moreover, high-density volumes identified as sulfides were detected in two xenoliths, showing no relation with the spinel layering in one case and a preferential concentration along fractures in the other. Given the variety of textures and mineral assemblages of mantle xenoliths worldwide, the results are used to suggest experimental and analytical protocols for the characterization of these materials.

Cathodic microenvironment reconstruction boost electrocoagulation treatment of photovoltaic wastewater

Electrocoagulation has emerged as a rapidly advancing area in the field of wastewater treatment due to its capability to eliminate pollutants that are typically resistant to filtration or chemical treatment methods, as well as its overall effectiveness, which is often impeded by the formation and growth of flocs. In this study, simulated photovoltaic wastewater was treated using the electrocoagulation method, with cathodic water reduction employed to induce a highly efficient electrocoagulation rate towards the removal of SiO2 and F−. Our results demonstrate that the optimal conditions for this process involved the use of an Al anode, Nickel foam as cathode, an inter-electrode distance of 1.0 cm, a current density of 30 mA cm−2, a stirring speed of 300 rpm, sodium chloride as supporting electrolyte, and an initial pH of 7. Our experimental findings indicated satisfactory performance with respect to EC, as evidenced by the reduction of F− content from 25 mg L−1 to 3.68 mg L−1, and the complete removal of SiO2 from 16 mg L−1. Furthermore, electrochemical analysis and texture characterization revealed that the overall rate of flocculation was dependent on the cathodic material, with in-situ generated OH− in the electrolysis cell influencing the microenvironment of iron hydroxide floc formation and sedimentation. Our study offers conclusive evidence that the optimal cathodic material capable of intensifying OH− concentration from water dissociation is key to achieving superior electrocoagulation performance.

Effects of Variated Final Temperature and Workpiece Thickness for Hot Rolling of Aluminum Alloy EN AW-8011

Hot rolling in the process chain of aluminum-rolled products presents the critical element of material quality and influences productivity. To increase the letter demand modifications of hot rolling, the consequential changes of microstructure, crystallographic texture, and mechanical and formability properties must be acknowledged and consistently considered when planning the rolling process and rolled product. Achieving lower thicknesses of the hot-rolled band would enable fewer passes with cold rolling; consequently, hot rolling with the same number of passes can be completed with lower temperatures. Microstructural and texture characterizations conducted using the light microscope and scanning electron microscope, respectively, of the 3.25 mm hot-rolled band revealed that the smaller grains appeared in the center of the cross-section, unlike for the 6 mm hot-rolled band, where smaller grains were detected on the top and bottom positions of the cross-section. Furthermore, the comparison also shows that the 6 mm hot-rolled band had 64% of random texture components and 83% of recrystallized grains, whereas the proportional adjustment for the 3.25 mm hot-rolled band had 42% of random texture components and 55% of recrystallized grains. For the mechanical testing results, the elongation values in rolling and transverse directions significantly differ only in the case of a hot-rolled band of 3.25 mm. Consequently, the earing results are more than 1.5% higher for the 3.25 mm hot-rolled band, than the 6 mm hot-rolled band.

Comparison of Optical and Stylus Methods for Surface Texture Characterisation in Industrial Quality Assurance of Post-Processed Laser Metal Additive Ti-6Al-4V.

Additive manufacturing technologies enable lightweight, functionally integrated designs and development of biomimetic structures. They contribute to the reduction in material waste and decrease in overall process duration. A major challenge for the qualification for aerospace applications is the surface quality. Considering Ti-64 laser powder bed fusion (LPBF) parts, particle agglomerations and resulting re-entrant features are characteristic of the upper surface layer. Wet-chemical post-processing of the components ensures reproducible surface quality for improved fatigue behaviour and application of functional coatings. The 3D SurFin® and chemical milling treatments result in smoother surface finishes with characteristic properties. In order to characterise these surfaces, three methods for surface texture measurement (contact and non-contact) were applied, namely confocal microscopy, fringe projection and stylus profilometry. The aim of this work was to show their suitability for measurement of laser powder bed fusion as-built and post-processed surfaces and compare results across the evaluated surface conditions. A user-oriented rating of the methods, summarising advantages and disadvantages of the used instruments specifically and the methods in general, is provided. Confocal microscopy reaches the highest resolution amongst the methods, but measurements take a long time. The raw data exhibit large measurement artefacts for as-built and chemically milled conditions, requiring proper data post-processing. The stylus method can only capture 2D profiles and the measurement was restricted by particle agglomerations and craters. However, the method (process and instrument) is entirely standardised and handheld devices are inexpensive, making it accessible for a large group of users. The fringe projection method was the quickest and easiest regarding measurement and data post-processing. Due to large areal coverage, reproduction of location when performing repeat measurements is possible. The spatial resolution is lower than for confocal microscopy but is still considered sufficiently high to characterise the investigated surface conditions.

Revisiting the genesis of the adakite-like granitoids in collisional zones: Water-fluxed melting of intermediate to felsic rocks with dilution by low Sr/Y phases

Abstract High-Sr/Y granitoids in continental settings are sometimes erroneously regarded as the products derived from partial melting of thickened/delaminated mafic lower curst under relatively higher pressures (&amp;gt;1.5 GPa) in a collisional orogenic setting. In fact, multiple magmatic processes in the trans-crustal magma system, such as recycling of antecrysts, crustal assimilation, and fractional crystallization, can create or modify the primary “adakitic” signature. As a result, the generation of adakitic magmas in continental settings remains controversial from a bulk-rock perspective. Here, we address the origin of adakitic plutonic rocks through geochemical and textural characterization of rock-forming minerals in the pyroxene-bearing Zhuyuan granodiorite, West Qinling, China. The Zhuyuan granodiorite formed in a post-collisional setting and primarily consists of resorbed orthopyroxene, three types of clinopyroxene, amphibole, two types of plagioclases, K-feldspar, biotite, and quartz. Type-1 Cpx has high XMg (70.0–81.7). Type-2 Cpx displays normal zoning and decreasing XMg (80.9 to 71.5) from the core to rim. Type-3 Cpx is reversely zoned, where the rims have higher XMg (75.5–86.9), Ni, Cr, suggesting a recharge event. Orthopyroxene has high-Ni and -Cr contents, as well as high XMg (80.9–82.8), indicative of antecrysts that grew in mafic magma reservoirs. The injection of magmas from different sources is supported by sieve-textured plagioclase and crystal size distributions of non-poikilitic amphibole. Finally, non-sieve textured plagioclase, biotite, K-feldspar, and quartz are late-crystallized phases, indicative of an orthocrystic origin. The melts in equilibrium with these orthocrysts display significantly higher Sr/Y values than the magma batches that crystallized other mafic phases (i.e., amphibole, clinopyroxene, and orthopyroxene). Thus, we propose that the system involved an initial high-Sr/Y melts in equilibrium with the orthocryst assemblage was generated by water-fluxed melting of intermediate to felsic sources. The addition of low Sr/Y non-orthocrysts (e.g., amphibole and pyroxene) and associated melt diluted the original “adakitic signal” in the magma reservoir and drove the bulk composition to more mafic values. Consequently, the Zhuyuan pyroxene-bearing granodiorite represents a mixture of crystals with diverse origins and distinct magma batches of various compositions (from felsic to mafic compositions). Our study emphasizes that the origin of adakitic granitoids cannot be clearly deciphered without geochemical analysis of the constituent minerals. We also suggest that Sr/Y values in plutons should be cautiously used in paleo-crustal thickness estimates in collisional settings because of possible open system scenarios as described here.