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Laser forming is a highly flexible and iterative contactless thermomechanical forming process that utilises a defocused laser beam to induce material shortening and bending. There is a high potential for the use of laser forming in rapid prototyping, small and unique batch production; however, to achieve that potential a certain level of automation is required. The presented work seeks to address this need of automation by proposing an end-to-end sheet-metal manufacturing system utilising laser forming and cutting, where the input for the system is a 3D CAD model and the output is a manufactured product. The contribution of the presented work is interconnected laser forming and cutting framework. The presented framework consists of subsystems for automatic extraction of geometrical information from a CAD model, process planning and generation of manufacturing information, scheduling of tasks and a feedback control loop for laser forming. The framework is experimentally validated and has shown consistent forming and cutting behaviour on two types of parts with variation in cutting features, bend angle and lengths of the bend's free edge. [ABSTRACT FROM AUTHOR]

Within the manufacturing industry, hole flanging is an essential process for forming local features in sheet metal. To enhance the flanging height, the diameter of the prefabricated hole should be reduced. However, the undersized diameter of the hole may result in a crack during the flanging process. Combining the electropermanent magnet (EPM) technique with the stamping process, a composite flanging method with incremental feed is proposed to improve sheet forming performance based on the superposition principle of magnetic circuits. Through a symmetric flanging model, the thickness distribution, contour, and forming height of flanging zones are simulated, measured, and found to be reasonably consistent with related theories. The results show that the built model is suitable for investigating flanging deformation behavior. Flanging processing was performed on 304 stainless steel plates with various laser cutting predrilled hole radii. Under various increment rates, the flanging inclination angle is measured and compared through finite element method (FEM) and experiment. Furthermore, when the plate thickness ratio to the prefabricated hole diameter is 0.11, the limit circular hole flanging coefficient can reach 2.22, which is an improvement of 4.83% compared to the traditional flanging process. [ABSTRACT FROM AUTHOR]

Purpose: The investigation aims to improve Nd: YAG laser technology for precision cutting of carbon fiber reinforcing polymers (CFRPs), specifically those containing newly created resin (NDR) from the polyethylene and polyurea group, is the goal of the study. The focus is on showing how Nd: YAG lasers may be used to precisely cut CFRP with NDR materials, emphasizing how useful they are for creating intricate and long-lasting components. Design/methodology/approach: The study employs a systematic approach that includes complicated factorial designs, Taguchi L27 orthogonal array trials, Gray relational analysis (GRA) and machine learning predictions. The effects of laser cutting factors on CFRP with NDR geometry are investigated experimentally, with the goal of optimizing the cutting process for greater quality and efficiency. The approach employs data-driven decision-making with GRA, which improves cut quality and manufacturing efficiency while producing high-quality CFRP composites. Integration of machine learning models into the optimization process significantly boosts the precision and cost-effectiveness of laser cutting operations for CFRP materials. Findings: The work uses Taguchi L27 orthogonal array trials for systematically explore the effects of specified parameters on CFRP cutting. The cutting process is then optimized using GRA, which identifies influential elements and determines the ideal parameter combination. In this paper, initially machining parameters are established at level L3P3C3A2, and the optimal machining parameters are determined to be at levels L3P2C3A3 and L3P2C1A2, based on predictions and experimental results. Furthermore, the study uses machine learning prediction models to continuously update and optimize kerf parameters, resulting in high-quality cuts at a lower cost. Overall, the study presents a holistic method to optimize CFRP cutting processes employing sophisticated techniques such as GRA and machine learning, resulting in better quality and efficiency in manufacturing operations. Originality/value: The novel concept is in precisely measuring the kerf width and deviation in CFRP samples of NDR using sophisticated imaging techniques like SEM, which improves analysis and precision. The newly produced resin from the polyethylene and polyurea group with carbon fiber offers a more precise and comprehensive understanding of the material's behavior under different cutting settings, which makes it novel for kerf width and kerf deviation in their studies. To optimize laser cutting settings in real time while considering laser machining conditions, the study incorporates material insights into machine learning models. [ABSTRACT FROM AUTHOR]

Laser-assisted turning (LAT) involves locally heating a rotating workpiece using a focused laser beam before the removal of material. A key aspect in optimising productivity with laser-assisted turning is understanding the thermal relationship between laser heating, the improved material removal rate, and machinability. Consequently, in this paper, a thermal heating and laser-assisted turning finite element model and experiments were conducted to assess the machinability of an Al/SiC p MMC workpiece, considering the circumferential location of the laser beam from the cutting point. The results confirm that laser power and cutting velocity influence the temperature profile from the laser spot to the tool point and the heat-affected depth. Positioning the cutting tool closer to the laser spot effectively reduces the Von Mises stress during cutting at higher cutting temperatures. At the same time, the experiment indicates an increased risk of directly heating the tool, which can affect the integrity of the cutting tool. The work further reveals that at specified cutting velocities, lower specific cutting energy improves the tool condition and surface quality of the machined parts. Based on a range of material removal rates and laser-specific energy density, a new criterion for optimal laser-tool circumferential distance was determined. Establishing this distance can act as a guide for the laser-assisted turning of Al/SiC p metal matrix composites and potentially other materials. [ABSTRACT FROM AUTHOR]

The hydrogen embrittlement behavior of a prerolled Fe–15Mn–0.65C–2Al–2Si high‐Mn steel with various cut‐edge properties is studied via hydrogen precharging and slow strain rate test. In the presence of hydrogen, samples prepared by laser cutting under atmosphere of N2 exhibit the best total elongation at about 39%. Press blanking produces severe shear deformation, tensile residual stresses, and strain‐induced martensite, resulting in a high risk to hydrogen‐induced cracking. With compressive residual stresses produced from waterjet, corresponding samples exhibit the lowest elongation loss against hydrogen. Despite hydrogen charging, the fracture surfaces show transgranular quasi‐cleavage features, for which mechanical twinning from prerolling plays a critical role. The hydrogen‐enhanced decohesion mechanism accounts for cleavage fracture since hydrogen segregation reduces cohesive stress at twin boundaries. [ABSTRACT FROM AUTHOR]

Efficient cutting of float glass can be achieved by using 532 nm nanosecond laser with the bottom-up spiral scanning method. Due to the obvious thermal effect when the nanosecond laser acts on the glass, it will cause glass edge chipping, white spots on the side wall surface, surface micro cracks and voids and other defect behaviors. Focusing on this problem, the single-factor experimental method was used to explore 532 nm laser hole cutting defect behavior. The results show that the laser pulse frequency is the key factor affecting the defect shape. Improper pulse frequency and pulse energy will seriously increase the glass edge chipping and the surface roughness of hole wall, and also produce uneven regional white spots. Increasing the scanning speed will reduce the surface roughness of hole wall. Smaller spiral overlap rate will cause the corrugated surface morphology of glass hole wall. When the hole wall quality is poor, the micro cracks and voids are more obvious. [ABSTRACT FROM AUTHOR]

A cost‐effective approach to provide diamond platelets containing nitrogen vacancy center ensembles (NVs) in the range of ppm is investigated. Industry‐type high‐pressure–high‐temperature‐diamond type 1b containing a high number of interstitial nitrogen in the range of several tens of ppm are used and small diamond platelets (size ≈1 × 1 mm2, thickness ≈300 μm) are prepared by laser cutting and polishing. The nitrogen is converted into NV by means of high‐energy electron irradiation of 10 MeV and annealing at 900 °C. Variations in the irradiation dose between 0.5E18 1/cm2 and 2E18 1/cm2 result in different densities of NV. The diamond platelets are analyzed with regard to their nitrogen concentration and photoluminescence as well as optically detected magnetic resonance is used to investigate the usability for a NV‐based magnetometer. A method to calculate the ratio of negatively to neutrally charged NV (NV−/NV0) is proposed that uses the photoluminescence intensities of the spectrum at 575 and 638 nm, namely, the zero‐phonon lines of NV− and NV0. [ABSTRACT FROM AUTHOR]

Cell-based assays are heavily relied on in the drug discovery pipeline, quickly pairing down large compound libraries to a manageable number of drug candidates for further characterization and evaluation. Monolayer cultures in which cells are deposited onto the bottom of well plates are the workhorse of many of these screens despite continued evidence of their inability to predict in vivo responses. Three-dimensional (3D) culture platforms can generate tissue-like environments with more representative cellular phenotypes than monolayers but have proven challenging to incorporate into already-developed workflows. Scaffold-based approaches are a tractable means of generating tissue-like environments, supporting cell-laden gels whose preparation is analogous to depositing cells in a well plate. Here, we describe supported gel slab (SGS) scaffolds prepared from commercially available materials, an adhesive spray, and a laser cutter. These cell-containing scaffolds can readily fit into well plates, providing a format compatible with current liquid handlers and analytical instrumentation. The scaffolds enable the evaluation of cellular responses in individual or stacked structures, which contain extracellular matrix-rich microenvironments. With a series of demonstrations, we highlight the utility of the readily assembled SGS scaffolds to quantify cellular responses. These readouts include confocal microscopy, quantifying cellular invasion in Transwell-like and stacked formats, generating multilayered spheroid-on-demand structures capable of providing spatially resolved maps of drug responses, and identifying potential chemotherapies in a screening application. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate a method of measuring the flexural elastic modulus of ceramics at an intermediate (~millimeter) scale at high temperatures. We used a picosecond laser to precisely cut microbeams from the location of interest in a bulk ceramic. They had a cross-section of approximately 100 μm × 300 μm and a length of ~1 cm. They were then tested in a thermal mechanical analyzer at room temperature, 500 °C, 800 °C, and 1100 °C using the four-point flexural testing method. We compared the elastic moduli of high-purity Al2O3 and AlN measured by our method with the reported values in the literature and found that the difference was less than 5% for both materials. This paper provides a new and accurate method of characterizing the high-temperature elastic modulus of miniature samples extracted from representative/selected areas of bulk materials. [ABSTRACT FROM AUTHOR]

Among non-destructive testing methods, a group dedicated to the assessment of the state of residual stresses can be distinguished. The method of measuring residual stresses using the Barkhausen noise method has many advantages, as evidenced by the number of publications. The residual stresses in metal products are important for the further processing of such metal, such as laser cutting or bending. The results presented in this work are of an experimental nature, and the presented method of calibration of measuring heads shows how various research techniques can be used to correlate results. The research was carried out for structural steel due to the market share of this type of steel. The method can be used to measure the residual stresses in ferromagnetic metal products in order to assess their directions and quantify them. A prerequisite for the use of this measurement method is that the amplitude and geometry of the Barkhausen noise are adequately correlated to the specific values of the state of stress depending on the tested steel grade or other metals. In this study, a method for calibrating measuring sensors for the residual stress measurements is presented, as developed by the authors. The method involved conducting bending tests in both numerical modeling and experimental tests. During the bending tests, changes in the magnetic field (Barkhausen noise waveform) were recorded, taking into account the state of elastic stresses. Correlating the results of the numerical calculations and Barkhausen noise measurements made it possible to determine the quantitative values of the residual stresses in the steel sheets. Thanks to the method used, very accurate measurement is possible, and the obtained results are repeatable. [ABSTRACT FROM AUTHOR]

Carbon fiber–reinforced plastics (CFRP) are widely used in the aeronautic aerospace and manufacturing industries due to their excellent performance. However, due to the structural characteristics of CFRP, its process efficiency is low, the surface quality is poor, and it is easy to cause tool wear. In this study, the effect of five-tool types (conventional milling tool, rhombus tooth milling tool, electroplated mill-grinding tool, slotted mill-grinding tool, laser-trimmed milling-grinding tool) and process parameters (spindle speed, feed rate, radial cutting depth) on tool life, process quality, and accuracy was systematically studied. The cutting force of the three types of electroplated diamond mill-grinding tools and the surface roughness of the processed CFRP are lower than that of the conventional milling tool and larger than that of the rhombus tooth milling tool. The residual chip on the surface of the slotted mill-grinding tool is less than that of the electroplated mill-grinding tool, but its cutting force and the surface roughness of the workpiece are greater than those of the electroplated mill-grinding tool. The main cutting and radial force of the trimmed mill-grinding tool are 9.5 N and 1.26 N, respectively. The surface roughness is about 2.524 µm. Due to the laser-trimmed mill-grinding tool having neat and sharp edges which can shear carbon fiber effectively, there are no obvious burrs on the processed CFRP. Moreover, the processed surface roughness was significantly reduced, and only a slight wear of the tool occurred. More importantly, the process debris can easily flow out of the straight groove of the laser-trimmed mill-grinding tool, resulting in a sharp edge of the tool, which reduces the cutting force. The laser trimming has a slight effect on the surface roughness but a more important effect on the cutting forces. The overall process performance of the laser-trimmed mill-grinding tool is close to that of CFRP special tool (rhombus tooth milling tool), but its price is about one-fiftenth that of special tools. Therefore, the electroplated diamond milling tool with improved structure and optimized process parameters can be an ideal tool for mill-grinding CFRP. [ABSTRACT FROM AUTHOR]

This paper is focused on the analysis and optimization of kerf width obtained in fiber laser cutting of 3mm thick S235 steel plate using oxygen as assist gas. Focus position, cutting speed and assist gas pressure were considered as important input parameters, and were systematically varied at 3 levels during experimentation, in accordance with Box-Behnken experimental design. A second order non-linear mathematical model for the prediction of kerf width was developed and analyzed with respect to three selected parameters. The unknown coefficients of the mathematical model were found by the method of least squares. The conducted analysis showed dominant effects of focus position and cutting speed with positive and negative correlation with kerf width, respectively. Focus position of 1 mm, cutting speed of 3.6 m/min and assist gas pressure of 0.75 bar should be used in order to achieve the smallest value of kerf width. To determine laser cutting parameters to obtain target kerf width value of 0.4 mm, and at the same time maximize material removal rate, laser cutting optimization model was defined and solved using genetic algorithm. It is shown that the combination of fiber laser cutting parameters: focus position f=1.4mm, cutting speed v=3.6m/min and assist gas pressure p=0.89 bar ensures maximum productivity of 4320 mm3/min, while ensuring the targeted kerf width value of 0.4mm. [ABSTRACT FROM AUTHOR]

Kevlar fabric reinforced plastics (KFRPs) are a type of composite material that consists of many layers of fabrics. In recent years, laser machining has surpassed both traditional and unconventional techniques because of its noncontact machining mode. In this research, polypropylene (PP) was used to reinforce Kevlar-129 fiber. Ten Kevlar layers were compressed-molded between Polypropylene layers to make the laminates. Cutting profiles of 25 mm x 25 mm was accomplished with the aid of fiber laser machining gear operating at a wavelength of 1070 nm with minimum laser power of 250 W and maximum of 400 Wand cutting speeds of 400 mm/min to 1000 mm/min with an interval of 200 mm/min with N2 as assisting gas at 10 bar. Kevlar polypropylene (K-PP) laminates' failure behavior was studied to see how much the polymeric matrix affected them. Scanning electron microscopy is another tool for studying the surface morphology. The first factor to think about is the very minimum of laser power required to make the incision. High power and low cutting speed generated clean cuts, while low power and high speed had laminate scribing. SEM analysis was performed on the surfaces that had been laser cut. In K-PP, the study of the laser-irradiated surface revealed that the K-PP material had a presence of recast/re-solidified polymer on the Kevlar fabric. Surface quality was found to be highest when cutting at 100 Hz compared to the other two modes. To better understand how laser machining affects Kevlar laminates, an investigation on surface roughness was carried out. [ABSTRACT FROM AUTHOR]

This study fixates on determining the optimum laser input parameters that simultaneously meet the desired kerf width and depth during CO2 laser cutting of various polymethylmethacrylate (PMMA) sheets. It has three contributions. The first is to model the cutting process of PMMA by polynomial curve fitting as a function of laser power, laser speed, and standoff distance. R-squared (R2), adjusted R2 and root-mean-square error (RMSE) criteria were taken into account to measure the performance of the proposed model. The effect of laser parameters on the process is investigated by analysis of variance (ANOVA) and sensitivity analysis. The second is to optimize the derived nonlinear regression models using genetic algorithm (GA), particle swarm optimization (PSO), whale optimization algorithm (WOA) and ant lion optimization (ALO) metaheuristic methods and compare the performances of the algorithms. The third is to compare the adequacy of the optimization process with the artificial neural network (ANN). The investigations exhibited that the best-fitting polynomials are obtained with the R2 and adjusted R2 values of over 99% and 97%, respectively. ANOVA and sensitivity test revealed that the sensitivity of the laser power, which is the most effective parameter, was 150 at low powers and decreased to 0 as the power value increased. When the nozzle distance is 4.1, the proposed metaheuristics gave effective and sufficiently accurate results. PSO stood out in terms of both best cost value (3.49 × 10–8) and relative error value (0.19%). The relative error of the ANN was found as 3% in terms of kerf depth. [ABSTRACT FROM AUTHOR]

This article presents a low-cost apparatus designed for teaching geometric optics experiments to first-year university students. The apparatus is made of medium-density fiberboard and uses glass optical elements to verify the laws of reflection and refraction. It allows for the direct observation of lateral displacement caused by a rectangular plate and the determination of the refractive index of the plate's material. Additionally, it enables investigation of refraction through a Littrow prism by determining its minimum deviation angle. The apparatus is economic, safe, and easy to use, making it suitable for educational purposes. The authors acknowledge the contributions of the Optics Research Group at Damietta University and Mohamed A. Atwa to the implementation of the apparatus. [Extracted from the article]

Keyhole laser-based processes have been adopted widely due to the high-quality welds and cuts that they produce and the accurately controlled dimensions of the end part. Fast-running simulation tools are required in order to estimate the dependence of process outputs, efficiency, and stability on the process variables. This work presents a fast-running simulation tool for keyhole laser-based processes with inert or no assisting gas that takes into account the effect of laser beam defocusing and the alteration of the effective reflectivity of the material due to the keyhole cavity. The model is built upgrading a successful model for the thermal phenomena based on finite differences and the enthalpy method. The presented model is compared to experimental results for the laser cutting process with both CO 2 and fiber laser sources and inert assisting gas. The model accurately predicts cutting depth and kerf, heat-affected zone width, and the dependence of the cutting depth on the position of the focal plane. The model manages to achieve reduced computational time enabling its utilization in process digital twins. [ABSTRACT FROM AUTHOR]

The moisture content of wood influences its machinability and the resulting quality of the machined surface. This study aims to explore the impact of varied moisture content on the final quality of beech wood cut by a CO2 laser (Fagus sylvatica L.). Laser cutting was performed on beech lumbers conditioned at moisture levels of 0%, 8%, 12%, and 18%. The laser-cut specimens were evaluated for surface roughness and waviness by using a stylus surface profilometer at three measuring locations: top, middle, and bottom. The total color difference ΔE was also assessed using a spectrophotometer at the same three locations. The most intriguing findings revealed that surface specimens with higher moisture content are lighter than those with lower moisture content. Specifically, the top areas of specimens with different moisture content exhibited lighter shades than those in the middle and bottom areas. Notably, the surface profile of the specimens remained unaffected by variations in moisture content levels. [ABSTRACT FROM AUTHOR]

The goal of this study was to determine the effect of cutting methods on the edges of selected materials applied in structural elements and floor sheathing of unmanned air vehicles. Three cutting methods for MGS L285 epoxy resin composites used for production of unmanned air vehicles manufactured in one of the European companies were presented. Composites reinforced by glass and aramid fibres are approved for certified production of air vehicle elements (AMC-20). Cutting was applied to each material using different technologies, such as: milling, laser cutting and abrasive water jet cutting. The authors focused on the edge quality of the tested specimens cut using various methods. Quality assessment was based on electronic microscopic scanning images and measurement of the specimen maximum damage. In summary, the choice of an appropriate composite cutting method depends on the type of material and its parameters, and it is crucial for the quality of the machined product. The authors focused on determining the selection of parameters for chosen cutting methods and materials used in the military unmanned aerial vehicle industry. Among the conducted tests, the results indicate that better cutting effects are obtained for milling methods in the case of GFRP + L285 (0.143 ± 0.073 µm) and CFRP + L285 (0.072 ± 0.027 µm), and the worst for AFRP + L285 (0.831 ± 0.269 µm). The water jet method gives the worst results in the cutting zone (results above 0.224 μm). [ABSTRACT FROM AUTHOR]

In the current scenario, industries face new challenges in cutting metal-based composites with good surface texture. The experimental investigation on laser cutting of magnesium AS2-Bimodal SiC composites is reported in the present work. Three bimodal compositions with varying proportions of micro-nano SiC reinforcement (75%-25%, 50%-50% and 25%-75%) were dispersed in AS21 alloy by stir-casting route. The comparison of quality characteristics such as surface roughness, kerf deviation and edge slope has been done to examine the behaviour of bimodal reinforcement with different laser cutting parameters. The experimental strategy was implemented based on the Taguchi L18 mixed design. The microstructure and cutting surface morphology has been analysed using OM, SEM and TEM. The results demonstrated that the AS21 composite with a bimodal structure of 75 vol.% micro-SiC and 25 vol.% nano-SiC showed better performance characteristics of CO2 laser cutting system due to uniform grain structure and homogeneous dispersion of nano-SiC reinforcement. [ABSTRACT FROM AUTHOR]

(TiZrHfNbTa)C high-entropy ceramics have wide range of application prospects due to their excellent performance, but their hardness and brittleness make them difficult to process. In this study, novel method based on nanosecond laser was used to cut (TiZrHfNbTa)C high-entropy ceramics. Results show that laser machining is efficient strategy for high-precision machining of (TiZrHfNbTa)C high-entropy ceramics. Slit width obtained via nanosecond-laser cutting is only 26.4 % of that obtained via mechanical cutting, and average roughness and maximum height difference of cut surface are 2.078 and 20.497 μm, respectively, which are smaller than those obtained through mechanical cutting (4.296 and 29.706 μm, respectively). Furthermore, removal mechanism under the action of nanosecond laser was investigated, and it was found that cut surface of (TiZrHfNbTa)C high-entropy ceramics formed thin oxide recast layer together with carbide underneath. This study provides important results for precision machining of (TiZrHfNbTa)C high-entropy ceramics. [ABSTRACT FROM AUTHOR]

The 3D geometry of the interaction zone in laser material processing is of major importance as it defines the absorption of the laser beam and may influence the hydrodynamics of the process. With the aim of measuring this geometry, which typically changes with frequencies in the order of 10 kHz, a single-frame polarimeter with acquisition rates of up to 75 kHz is presented in this work. It simultaneously records four images of the thermal process emission, through four linear polarizers with different orientations. The formulae required for the reconstruction of the 3D geometry from these images are derived and validated on an example of a heated steel sphere. The reconstructed geometry was found to be in good agreement with the examined sphere. An experimental example is also given of the application of this technology to geometry measurement of a highly dynamic laser cutting front at a framerate of 75 kHz. [ABSTRACT FROM AUTHOR]

In connection with the need to obtain a properly made and cut material and the appearance of the surface layer, new manufacturing technologies were used for tests, namely the laser cutting technology. This article describes the laboratory stand built for the purpose of research, as well as the possibility of using laser cutting on several sample materials (polymer films), together with an indication of the results obtained. The idea was to elaborate on the cutting technology that will be proper for manufacturing the desired type of spacers for ion-exchange membranes separating while maintaining the required level of product quality and chemical purity. The latter criterion was the basic one, due to the scope of use of the manufactured elements. This article also describes the problem encountered during the construction of the stand or during the research. The last part of this article describes the further steps of the research that will be carried out in the future along with a discussion and summary of the research performed. It is important from the point of view of the development of production technology, but also because of the characteristics of materials for the production of surface layers and coatings resistant to mechanical or thermal wear used in industry. The introduction of innovative solutions is also aimed at studying the improvement of the economics of the production of materials that are significant, in particular, for small- and medium-sized enterprises. [ABSTRACT FROM AUTHOR]

The fabrication of plasmonic 3D microstructures is still a challenge. In this study, the fabrication of gold‐nanoparticle (Au‐NP)‐filled acrylate‐based micron‐scale cuboids forming plasmonic 3D particles is investigated. UV curable acrylate is mixed with HAuCl4 and spin‐coated onto a fused silica wafer. UV light and heat treatment of the layer result in polymerization of the acrylate and formation of Au‐NPs with a plasmonic resonance ranging from 535 to 550 nm. The plasmonic resonance wavelength decreases slightly with increasing UV dose. The resonance wavelength can be shifted by a subsequent annealing process. The decreasing resonance wavelength with increasing annealing temperature is discussed as a result of the increasing Au‐NPs. The size and the distribution of the resulting gold particles in the acrylate matrix is investigated by transmission electron microscopy. The Au‐NPs‐filled acrylate layer is laser structured using a UV‐femtosecond laser, which allows the fabrication of adjustable micro‐cuboids with edge lengths down to 15 μm. The laser‐cut micro‐cuboids are transferred into isopropanol and the plasmonic properties of the structures in the liquid are successfully demonstrated. The presented concept allows easy and large‐scale fabrication of plasmonic microstructures with independently adjustable plasmonic properties and microstructural size and shape. [ABSTRACT FROM AUTHOR]

To reduce defects in wood laser processing, this study establishes a multi-field coupling model that reflects the coupling relationship between laser energy, auxiliary gas, and slit quality. It reveals the temperature field distribution and heat transfer during this process at a macroscopic level. Using the COMSOL Multiphysics 5.6 software to simulate laser processing with or without helium gas assistance, we show that helium-assisted laser processing positively affects the quality of wood processing. We further researched the influence of different laser powers and spot radii on ablation damage volume and gasification volume, and the results indicate that the adopted model effectively simulates the influence of laser power and auxiliary gas on laser cutting ability, accurately reflecting the impact of different process parameters on cutting depth and kerf width. The accuracy and effectiveness of this model were validated through comparison with experimental data. This research enhances process reliability and economic benefits through numerical simulation and prediction, expands theoretical research and engineering applications in the laser processing field, and optimizes and innovates wood processing technology. It provides a promising method for enhancing the added value of wood products and efficiently using wood resources. [ABSTRACT FROM AUTHOR]

This document is a special issue of the journal "Processes" focused on micro/nano manufacturing processes and optimization techniques. The articles in this issue cover a range of topics including the fabrication of micro/nano-structured surfaces, simulation and experimental investigation of laser manufacturing, and optimization techniques in microscale machining. The articles provide insights into various methods and technologies used in these areas and discuss their advantages, disadvantages, and potential applications. The authors also propose new approaches and techniques to address challenges and improve performance in micro/nano manufacturing processes. [Extracted from the article]

This study uses an infrared cutting laser system to dice GaAs wafers. The Taguchi method determines the laser wafer dicing parameters [laser power (W), depth of focus (μm), and platform speed (m/s)] in relation to the dicing yield and single-grain compressive strength. An orthogonal array (L9 33), a signal-to-noise ratio, and an analysis of variance are employed to study the effects of these parameters. The result shows that the laser wafer dicing yield ranges from 85.53% to 95.20%, with laser power accounting for 86.08% of the total variation, making it the most significant factor. Additionally, the wafer dicing yield is positively correlated with grain compressive strength. Grain defects and corner chipping produced during the cutting process will reduce the compressive strength of the grains. Under the optimized laser wafer cutting conditions, the dicing yield and grain compressive strength reached 95.87% and 331.93 N/mm2, respectively. [ABSTRACT FROM AUTHOR]

Robotic systems equipped with high-power laser sources are often employed for the production of battery packs for the electric mobility sector. Considering the strive toward a circular manufacturing economy, there is great interest in the possibility of reconfiguring such equipment for dismantling operations. The present study explores the hybrid use of a robotized fiber laser welding system, adapting its scope from joining of battery casings toward the separation of the same thin Al sheets, enabling the recycling of the internal cells of the battery pack. Process feasibility is assessed by tailoring the beam size as well as exploiting dynamic beam oscillation to perform the separation process. Dynamic beam oscillation allows us to obtain a smaller kerf width and greater process stability with respect to linear trajectories with larger beam sizes. The damage to underlying cells of the separation region was also assessed on different materials (Al, Ni-plated steel, and Cu). Greater surface modifications and higher peak temperatures (in excess of 800 °C) were recorded when employing dynamic beam oscillation with respect to linear trajectories. This research demonstrates a pathway for reutilization of the existing technological systems for a circular and sustainable production chain in the e-mobility sector. [ABSTRACT FROM AUTHOR]

Introduction: Self-coalescing microfluidic devices represent an exciting opportunity for leveraging viscous dominated flow phenomena to reconstitute a series of reagents with a single sample infusion. In a self-coalescing microfluidic device, spatially separated dried reagents are reconstituted using a single infusion. Due to the unique device geometry, the reagents remain spatially separated after infusion. As such, self-coalescing microfluidic devices have the potential to simplify point-of-care testing by simultaneously performing multiple colorimetric tests in one device. The current versions of these devices use standard, more costly microfabrication processes and are too small to be easily read by eye. Methods: Here, we created a low cost and scaled up version of a self-coalescing microfluidic device by using laser-cut-roll-based silicone tape. In addition to eliminating the need for cleanrooms, our approach simplifies the integration of assay reagents since they can be spotted onto a coverslip and covered with the tape microfluidic device. We empirically optimized our device, finding that flow rate significantly influenced the formation of self-coalescence as well as proper reagent reconstitution. Results and Discussion: When flow rates were too slow or fast, reagents would streak, leading to inadvertent mixing between different spatial locations. Our studies further revealed that geometry had a stronger influence on device operation in low-flow conditions. Our final optimized device exhibited a 100% success rate, demonstrated through self-coalescence with no reagent streaking at 100 μL/min, which enabled the isotropic diffusion of reagents. Furthermore, the spots are spatially separated and large enough to be visualized by the naked eye and captured by a smartphone camera for downstream analysis. Taken together, our innovative device leverages the advantages of sticker microfluidics and low-cost manufacturing methods to offer standalone functionality. This approach has the potential to significantly impact point-ofcare diagnostics, particularly in resource-limited regions. By enabling multiplexed diagnostic assays through our novel technology, we aim to provide accessible and affordable healthcare solutions. [ABSTRACT FROM AUTHOR]

This study investigates the effects of a water-guided laser on the cutting performance of AISI 1020 steel sheets of various thicknesses by comparing the results with respect to a conventional laser. For this purpose, a novel nozzle design has been devised enabling the delivery of laser beams to the workpiece conventionally as well as through water guidance. Diverging from prior literature, a fiber laser is used with a high wavelength and a laser power output of 1 kW. Experiments are conducted on steel sheets with thicknesses ranging from 1.5 mm to 3 mm using three different cutting speeds and laser power levels. Analysis focuses on assessing surface roughness, burr formation and heat effects on the cut surfaces for both conventional and waterjet-guided cutting. Surface roughness is evaluated by using a 3D profilometer and cut surfaces are examined through SEM imaging. The results showed that the waterjet-guided laser system greatly reduced surface roughness and minimized problems associated with traditional laser cutting such as kerf, dross adherence and thermal damage. The study revealed that cutting speed had a greater effect on surface roughness reduction than laser power, with the most noticeable differences occurring in thinner sheets. Furthermore, the investigation suggests that the waterjet-guided laser cutting system demonstrates superior performance relative to conventional methods, particularly in surface quality. [ABSTRACT FROM AUTHOR]

A stretchable active‐matrix (AM) display is a next‐generation display that breaks away from displaying limited information on flat and curved screens. However, the implementation of stretchable displays requires much more complex fabrication processes and meticulous efforts compared to traditional flat/curved displays. Here, the biaxially stretchable AM micro‐light emitting diode (LED) display on polydimethylsiloxane (PDMS) with liquid metal (LM) interconnects is reported. The pixel islands consisting of oxide TFTs and micro‐LEDs, which are fabricated on the polyimide (PI) substrate, are formed through green laser cutting and transfer to the PDMS substrate. LM interconnects integrate on the pixel island and PDMS by a lift‐off process. The oxide TFTs and micro‐LEDs comprising the 2T1C (2 TFT + 1 capacitor) pixel circuit on the PI island, along with LM interconnects, demonstrate stable electrical characteristics even under a relaxed state as well as when biaxially stretched up to 24%. For 24% stretching of display pixels with the same ratio of PI island and LM interconnects, the LM interconnects operate at 48% stretching. The combination of pixel island array and LM interconnects successfully demonstrates the implementation of a two‐axis stretchable display capable of displaying characters of "A", "D", "R", and "C" through AM driving. [ABSTRACT FROM AUTHOR]

To demonstrate the feasibility and improve the implementation of laser weeding, a static movable lift-adjustable closed fiber laser weeding device and system have been developed, followed by experiments and performance evaluations. Physical experiments were conducted on the energy required for laser cutting of weed stems, targeting four common larger weeds (Chenopodium album, Amaranthus spinosus, Setaria viridis, and Eleusine indica) in farmland and orchards. At the same irradiation distances, the energy required to cut the same type of large weed generally increases with increasing distances and stem diameters but decreases with increasing irradiation time. The variance of stems' power density after irradiation was larger and the values were more dispersed for Chenopodium album and Setaria viridis weeds, and the values were relatively scattered, while the power density values of Amaranthus spinosus and Eleusine indica weeds were more concentrated. When the irradiation time was 10 s, the 3.892 W/mm2 laser was sufficient to eliminate weeds and plants with the irradiation distances of 2 m. The 2.47 W/mm2 laser was more effective, as it killed weeds within a distance of 1 m in less than 1 s. This work demonstrates the feasibility of the laser weeding device and system that can completely cut off the stems of large weeds, and this technology has the potential to promote sustainable agriculture. [ABSTRACT FROM AUTHOR]

In this work, we focus on the prediction of the influence of CO2 laser parameters on the kerf properties of cut spruce wood. Laser kerf cutting is mainly characterized by the width of kerf and the width of the heat-affected zone, which depend on the laser power, cutting speed, and structure of the cut wood, represented by the number of cut annual rings. According to the measurement results and ANN prediction results, for lower values of the laser power (P) and cutting speed (v), the effect of annual rings (ARs) is non-negligible. The results of the sensitivity analysis show that the effect of v increases at higher energy density (E) values. With P in the range between 100 and 500 W, v values between 3 and 50 mm·s−1, and AR numbers between 3 and 11, the combination of P = 200 W and v = 50 mm·s−1, regardless of the AR value, leads to the best cut quality for spruce wood. In this paper, the main goal is to show how changes in the input parameters affect the characteristics of the cutting kerf and heat-affected zones for all possible input parameter values. [ABSTRACT FROM AUTHOR]

The aim of our study is to investigate the feasibility and outcomes of using a femtosecond laser (FSL) platform (Ziemer LDV Z8) for deep anterior lamellar keratoplasty (DALK), enabling the creation of mushroom-shaped graft–host junctions, lamellar cuts, and intrastromal tunnels, to facilitate the big bubble, in one step. We included wet lab experiments on nine porcine eyes to assess the laser accuracy and cuts depth using an anterior segment (AS) OCT. This was followed by an interventional prospective case series on 10 eyes with variant corneal pathologies. The Z8 system, with in-built intraoperative optical coherence tomography (iOCT), guided corneal scans and directed the cuts. ASOCT showed visible mushroom configurations, lamellar cuts, and tunnels. Deviations from the target were 1.6%, 2.6%, and 3.5%. Anterior lamellar removal was easy in all clinical cases, including corneal scarring. The intrastromal tunnel was found at the preset location and the mushroom configuration was acquired. A big bubble was achieved in all cases. Type 1, 2, and 3 bubbles were formed in eight, one, and one case, respectively. We describe a new approach to DALK in which the in-built iOCT-guided FSL enables safe, precise, controlled, and reproducible desired cuts in one step. The preliminary clinical outcomes were favorable. [ABSTRACT FROM AUTHOR]

Studies have shown that unconventional machining offers advantages when it comes to machining ceramics in the form of higher material removal rate (MRR) and better surface finish. This present study focuses on the experimental investigations using a fibre laser to cut 7 mm thick ceramic plates used as glazed floor tiles. It involved a systematic experimental study to determine the relationships between process parameters and machining characteristics. Based on the experimental results, regression equations are developed to estimate the responses as functions of the laser process parameters and gas pressure. The developed regression equations are then used in a particle swarm optimization (PSO) technique with a MATLAB algorithm to minimize glass formation and taper angle in the cutting region which, in turn, improves productivity and surface finish. The optimal parameters of the process are found based on the minimization of the taper angle with relatively low operating energy cost. [ABSTRACT FROM AUTHOR]

Based on the experimental results, this study develops a multi-objective optimization scheme to obtain the set of optimal process parameters for pulsed laser direct cutting of non-oriented silicon steel sheets for manufacturing motor core laminations. The experiments were conducted in the nital solvent, which was the one with the smallest thermal effect of laser cutting among the candidate environments of air, deionized water, alcohol, lubricant oil, sodium chloride solution, and nital solution. The laser was a pulsed Nd:YAG nanosecond laser and the thickness of the silicon steel was 100 μm. The effects of three laser process parameters, laser power (P), cutting speed (v), and pulse repetition rate (f) on the cutting qualities of the heat-affected zone (HAZ), cutting time (TC), and multiple dimensional accuracies of the cut core lamination were examined. The inspected geometric accuracies included the errors in inner and outer core diameters (ED1 and ED2), the error in tooth width (EL), and the roundness of inner and outer diameters (C1 and C2). The developed multi-objective optimization model was a PSI-based ELM-GA scheme consisting of the extreme learning machine (ELM) model for connecting the inputs and the outputs, the preference selection index (PSI) method for obtaining the weighted multi-objective function, and the genetic algorithm (GA) for process optimization. Through employing the predicted optimal process parameter set, the validation experiment showed that the errors between the prediction and the experimental result for the seven qualities of HAZ, ED1, ED2, C1, C2, EL, and TC were 4.04%, 6.25%, 4.02%, 0.48%, 2.14%, 5.09%, and 1.25%, respectively. The HAZ and geometric accuracy of the cut core laminations were qualified for the subsequent lamination assembly. Consequently, the merit of direct formation of ready-for-assembly core laminations without the need for any post-processing renders the proposed laser cutting scheme an economical and effective approach for manufacturing motor core laminations from thin silicon steel sheets. [ABSTRACT FROM AUTHOR]

Laser powder bed fusion (LPBF) is one of the most popular metal additive manufacturing technologies, which has found its applications in high-value sectors such as aerospace and biomedical devices. Some recent studies on the LPBF of stents have demonstrated its feasibility in the fabrication in thin strut structures including heart valve frames, as used in transcatheter aortic valve implantation (TAVI) for the treatment of severe aortic stenosis. The state of the art method of laser cutting TAVI frame limits the scope for novel concepts which are made possible by additive manufacturing. However, the surface quality and dimensional accuracy of LPBF parts are lower than that produced by laser cutting. To start the development of new TAVI concepts, the feasibility of manufacturing thin frames by LPBF has been investigated based on the SAPIEN 3 frame by Edwards Lifesciences. In this study, simplified frames with strut size from 0.3 to 0.5 mm have been successfully manufactured. The effects of strut size, strut angle, laser power and scan speed on the dimensional accuracy and surface quality were systemically studied. In addition, a representative SAPIEN 3 frame was manufactured and assessed with high-resolution X-ray CT scans. Good overall dimensional accuracy and low porosity were obtained for the SAPIEN 3 frame. However, inclined struts were found to have relatively low dimensional accuracy and poor surface quality. [ABSTRACT FROM AUTHOR]

This study examines the impact of cutting parameters on the fatigue properties of FeCoCrNiAl0.6 high‐entropy alloy under bi‐directional micro‐cutting. Utilizing Abaqus/fe−safe for analysis, we evaluated surface roughness, internal stress distribution, and fatigue longevity. Enhanced cutting speed resulted in smoother surfaces, whereas increased cut depth intensified surface roughness. Optimal cutting at 60,000 mm/min and 40 μm depth yielded a notable 91% rise in compressive stress (207 MPa) compared to slower speeds (108 MPa at 30,000 mm/min). Yield strength remained stable at 700 MPa across conditions. Fatigue resistance improved post‐bi‐directional cutting, with a 21.8–26.6% boost in life cycles, highlighting a consistent 10% advantage over single‐direction cutting. Highlights: The influence of bilateral micro‐cutting on fatigue performance was studied.The influence of micro‐cutting parameters on fatigue properties is studied.The release and transformation mechanism of residual stress in bilateral micro‐cutting is studied. [ABSTRACT FROM AUTHOR]

Fast-scan cyclic voltammetry (FSCV) is an electrochemical sensing technique that can be used for neurochemical sensing with high spatiotemporal resolution. Carbon fiber microelectrodes (CFMEs) are traditionally used as FSCV sensors. However, CFMEs are prone to electrochemical fouling caused by oxidative byproducts of repeated serotonin (5-HT) exposure, which makes them less suitable as chronic 5-HT sensors. Our team is developing a boron-doped diamond microelectrode (BDDME) that has previously been shown to be relatively resistant to fouling caused by protein adsorption (biofouling). We sought to determine if this BDDME exhibits resistance to electrochemical fouling, which we explored on electrodes fabricated with either femtosecond laser cutting or physical cleaving. We recorded the oxidation current response after 25 repeated injections of 5-HT in a flow-injection cell and compared the current drop from the first with the last injection. The 5-HT responses were compared with dopamine (DA), a neurochemical that is known to produce minimal fouling oxidative byproducts and has a stable repeated response. Physical cleaving of the BDDME yielded a reduction in fouling due to 5-HT compared with the CFME and the femtosecond laser cut BDDME. However, the femtosecond laser cut BDDME exhibited a large increase in sensitivity over the cleaved BDDME. An extended stability analysis was conducted for all device types following 5-HT fouling tests. This analysis demonstrated an improvement in the long-term stability of boron-doped diamond over CFMEs, as well as a diminishing sensitivity of the laser-cut BDDME over time. This work reports the electrochemical fouling performance of the BDDME when it is repeatedly exposed to DA or 5-HT, which informs the development of a chronic, diamond-based electrochemical sensor for long-term neurotransmitter measurements in vivo. [ABSTRACT FROM AUTHOR]

The cutting of thick glass is extensively employed in aerospace, optical, and other fields. Although ultrafast laser Bessel beams are heavily used for glass cutting, the cutting thickness and cutting quality need to be further improved. In this research, the high-quality cutting of thick glass was realized for the first time using ultrafast laser perforation assisted by CO2 laser separation. Initially, an infrared picosecond laser Bessel beam was employed to ablate the soda-lime glass and generate a perforated structure. Subsequently, a CO2 laser was employed to induce crack propagation along the path of the perforated structure, resulting in the separation of the glass. This study investigates the influence of hole spacing, pulse energy, and the defocusing distance of the picosecond laser Bessel beam on the average surface roughness of the glass sample cutting surface. The optimal combination of cutting parameters for 6 mm thick glass results in a minimum surface roughness of 343 nm in the cross-section. [ABSTRACT FROM AUTHOR]

An eco‐friendly organic compound, with rich redox sites, considered a promising cathode material for aqueous zinc‐ion batteries (AZIBs). Despite its potential, limited specific capacity and cycle instability impede its practical application. Herein, an organic compound, hexaazatriphenylene hexacarbonitrile (6CN‐HAT), is designed with a π–π conjugated aromatic structure, and integrated with MXene nanosheets to construct a flexible self‐supporting electrode (6CN‐HAT@MXene). Ex‐situ characterizations and theoretical calculations verify that the charge storage mechanism predominantly involves coordination and non‐coordination reactions between reactive C═N and ─CN sites with cations. The introduction of MXene nanosheets not only bolster the stability and electronic conductivity of the 6CN‐HAT@MXene but also expose additional active sites for cation coordination. As a cathode material in AZIBs, 6CN‐HAT@MXene exhibits an outstanding discharge specific capacity of 413 mAh g−1 at 0.05 A g−1. Remarkably, even after 5000 cycles at 5 A g−1, the discharge capacity retained 91%. Furthermore, based on the 6CN‐HAT@MXene electrode, a flexible micro‐zinc‐ion batteries with high area capacity of 257.4 mF cm−2 is prepared using laser cutting technology, highlighting its potential for future applications in portable and wearable electronic devices. [ABSTRACT FROM AUTHOR]

A high-power fiber laser was used to cut AZ31B magnesium alloy. The effects of laser cutting speed, assisted air pressure, and defocus on cutting quality were studied systematically. Scanning electron microscope and ultra-depth-of-field three-dimensional microscope were used to observe the morphology of kerf and the cutting surface. The results show that the kerf width at the straight line and the kerf width at the sharp corner always keep the synchronous change law. The cutting surface can usually be divided into three areas: top area, scour area, and stripe area. The change of the area of the three regions has an important influence on the roughness value of the cutting surface. Studying the variation of roughness by studying the variation of three areas is applicable to laser cutting speed and assisted air pressure, but not to defocus. The slag height decreases from 75.87 to 46.83 μm with the increase of laser cutting speed. The slag height decreases rapidly to 52.88 μm and then increases slowly to 61.74 μm with the change of defocus. The slag height decreases rapidly from 58.37 to 24.81 μm with the increase of assisted air pressure. [ABSTRACT FROM AUTHOR]

Fiber laser cutting machines are widely used in industry for cutting various sheet metals. Hardox steel is widely used in the construction of machinery and equipment that are subjected to wear and impact due to its anti-wear properties and good impact resistance. In this experimental study, the effect of input parameters including laser output power (LOP), laser-cutting speed (LCS), and focal point position (FPP) of fiber laser on the surface roughness and kerf width of Hardox 400 steel sheets are studied. In addition, the optimization of input parameters to achieve the desired surface roughness and kerf width are investigated and analyzed using the response surface methodology (RSM). The experiments are performed using a 4 kW fiber laser-cutting machine and the output results including surface roughness and kerf width are measured using roughness meters and optical microscope. The results of the analysis of variance (ANOVA) for surface roughness and kerf width show that the FPP and LCS are the most significant process parameters affecting the surface roughness and kerf width. With a positive focal point, the surface roughness decreases while the kerf width increases. With increasing the laser-cutting speed, both the surface roughness and kerf width decrease. [ABSTRACT FROM AUTHOR]

This study investigates laser-induced damage in thin silicon (Si) wafer ablation both experimentally and numerically. A 40-W continuous-wave CO2 laser is employed as the volumetric heat source. Experiments are conducted that involve variations in the laser cutting speed from 5 to 20 mm/s and the number of passes from one to three while maintaining a constant laser power of 40 W for investigation. The measured output parameters include surface morphologies, heat-affected zone (HAZ), and kerf width. For the first time, a finite element solution based on the brittle–ductile transition (BDT) phenomenon is introduced to predict temperature-stress gradients in the laser cutting region. Johnson–Cook (J-C) plasticity, along with the introduced damage criteria, are employed to analyse the cutting characteristics. The results show that the lowest CO2 laser speed and minimal number of passes enhance Si wafer quality. Nevertheless, increasing cutting speed and the number of passes significantly intensify material ablation and oxidisation due to elevated laser heat input. Using optimal parameters, numerical analysis shows a high level of agreement with experimental findings. Transverse/longitudinal stresses correlate with temperature, while the longitudinal stress is substantially lower compared to the transverse stresses due to thermal expansion and the direction of heat transfer. Following that, computed assessments of compressive and tensile stresses are used to refine specific laser parameters and locations for experimental setup. [ABSTRACT FROM AUTHOR]

In the field of ultra-thick plate cutting, thermal cutting using high-temperature heat is used rather than mechanical cutting, and research is being conducted to increase the efficiency of cutting. In this paper, in order to improve cutting efficiency, a hybrid cutting head using both laser and gas cutting was designed, and the optimal cutting conditions were demonstrated through an experiment for cutting ultra-thick plate using the manufactured cutting head. The plate material used 100 t carbon steel, and a multi-axis hybrid method was adopted. As a result of the experiment was confirmed that the cutting speed was improved more than twice as much as when using the single cutting method, and the optimal speed condition in which sludge did not occur was derived. The maximum cutting speed was 600 mm/min, and the optimal cutting speed at which sludge did not occur was confirmed at 550 mm/min. [ABSTRACT FROM AUTHOR]

Nickel-based superalloy Inconel718 is a typical difficult-to-machine material with the characteristic of high strength and hardness. Demands for micro parts of nickel-based superalloy Inconel718 are growing in aerospace, biomedical and other fields. Laser-assisted micro-milling (LAMM) can realize precision machining of the workpiece because of its lower cutting force. However, the machining mechanism and the change law of cutting force during LAMM of nickel-based superalloy Inconel718 are still unclear. There is a crucial need for modeling of LAMM Inconel718. This paper explores LAMM of nickel-based superalloy Inconel718 and realizes the simulation of LAMM process. A three-dimensional transient heat transfer finite element (FE) model is established to predict the temperature distribution of a Gaussian heat source in LAMM. Multiple sets of simulations of laser pre-heating with various laser power are conducted to analyze the temperature fields of workpiece and determine the appropriate laser parameters. A novel 3D model of the full machining process of LAMM Inconel 718 is constructed by ABAQUS with multi-subroutine, a fully coupled thermal-mechanical process is achieved. A modified Johnson-Cook constitutive model is used to reflect the size effect and flow stress of LAMM Inconel 718. Finally, the validity of the models is verified by experiments. Based on the verified model, the appropriate laser pre-heating parameters are obtained, and the prediction of cutting forces of LAMM Inconel718 is achieved. [Display omitted] • Appropriate laser parameters are determined based on laser pre-heating FE model. • Fully thermo-mechanical coupling of LAMM Inconel718 simulation is achieved. • LAMM Inconel718 experiments are conducted and verified the validity of the models. [ABSTRACT FROM AUTHOR]

Ultrashort pulsed laser, due to its extremely high peak power density, has been widely used for high precision, rapid and programmable manufacture. Several models, such as two-temperature model (TTM) and a molecular dynamics model, have been proposed for the temperature simulation or clarifying the nonequilibrium phase transition. However, there exists no an appropriate theory guiding for effective selection of laser parameters. Here, an equivalent power density (EPD) model was proposed to describe the morphological evolution of the phase transition area and guide for proper laser parameters selection. Based on EPD model, theoretical analysis was carried out for laser cutting, laser processing in transparent materials, and the formation of laser induced periodic surface structures (LIPSS), and it was verified that material phase transition can be determined by both the laser power density and the temperature field. Through the three kinds of laser processing experiments, including laser cutting, laser dotting and scanning as well as laser welding glass, it was demonstrated that the experimental results can be well explained by the EPD model. [ABSTRACT FROM AUTHOR]

Drilling deviated wellbores has raised concerns about proper cutting transport. Cuttings settling downhole can create stationary cutting beds, causing drilling mishaps like stuck pipes. High fluid velocity is typically required to efficiently erode a stationary bed, but this is constrained by hydraulic and wellbore geometry. When this occurs, pipe rotation can erode the bed mechanically and enable efficient cutting transport even with lower fluid velocities. Therefore, this study formulated water-based mud (WBM) with hydroxyapatite nanoparticles (n-HAp) to examine the effect of pipe rotation on cutting transport in deviated wells. It was compared with copper II oxide nanoparticles (CuO NP) in terms of rheology, filtration, and cutting transfer efficiency (CTE). The CTE of n-HAp amounts (0.4–2.0 g) in moving cuttings with diameters of 0.80 to 3.60 mm through deviated wellbores of 40 to 65° at a 3.5 m/s fluid velocity with 60 and 120 rpm pipe rotation speeds was determined. Compared with CuO NP, n-HAp findings demonstrated enhanced rheology and CTE. However, for fluid loss control, n-HAp was slightly less effective compared to CuO NP. For all deviated angles, n-HAp increased the CTE by 9.5–50%, while CuO NP increased it by 3.4–38.7% at 120 rpm. Compared with 60 rpm, a higher CTE occurred at 120 rpm. Moreover, CTE occurs in the following manner: 40° > 65° > 45° > 60° > 50° > 55°. It suggests that stationary bed formation is more likely to occur at inclinations of 50–55°. These findings are crucial for drilling deviated wells. [ABSTRACT FROM AUTHOR]

The present study focused on the machinability of Ti-3Al-2.5 V for wire-electrical discharge machining (WEDM) using "BroncoCut-X wire" (zinc-coated copper wire). The machining characteristics have been evaluated by varying wire-tension (Tw), wire-speed (Sw), flushing-pressure (Pf), discharge current (Id), and spark-on-time (Son). The response characteristics associated with cutting-speed (Cs), kerf-width (KW), and surface roughness (RA) have been collected and analyzed using main-effect plots, scanning electron microscope (SEM), and analysis of variance (ANOVA). The maximum Cs and minimum KW and RA are obtained upto 8.90 mm/min, 3.34 µm and 0.2218 mm, respectively. Additionally, the novelty lies in the smart hybrid prediction tool considering the conflicting nature of responses are converted into single responses using Grey Relation Analysis (GRA) and Fuzzy Interference System (FIS) (Namely: Gray-Fuzzy Reasoning Grade (GFRG)). Furthermore, the optimal performance is calculated using Rao-algorithms (i.e., Rao1, Rao2, and Rao3). The obtained ideal machining condition is 16N wire-tension, 3 m/min wire-speed, 8 kg/mm2 flushing-pressure, 21A discharge current, and 14 µs spark-on-time. The result has also been compared with the JAYA-algorithm and improved-grey wolf optimizer (I-GWO) to demonstrate the efficacy of the intended approach. The confirmation test has been conducted and obtained that the GFRG-based results are further improved by using a hybrid GFRG-based Rao-algorithm of 9.55%, 2.36%, and 7.99% as Cs, KW and RA, respectively. Furthermore, this study shows that the proposed multi-objective optimization method not only leads to more stable solutions but also to shorter run times and enhanced quality to support engineers in reducing the cost of item failures. [ABSTRACT FROM AUTHOR]

Employing density functional theory within the Wien2k code, first‐principle calculations are conducted to explore the impact of applied pressure up to 80 GPa on the structural, mechanical, thermal, and electronic characteristics of BaPbO3. Demonstrating metallic behavior with ductile attributes, BaPbO3 exhibits a decreasing anisotropic nature under escalating pressure. Evaluation of cubic elastic constants, optimization curves, and enthalpy of formation indicates the compound's mechanical and thermodynamic stability under high pressure conditions. Calculated values of C11 and C44 reflect heightened resistance to unidirectional compression and increased stiffness under pressure. These mechanical properties position BaPbO3 as a promising candidate for diverse industrial applications across varying pressure ranges, including utilization in piezoelectric materials (0–20 GPa) and high‐pressure sensors. Additionally, charge density contours suggest a combination of ionic (Ba─Pb) and covalent bonding (Pb─O) within the compound's constituent atoms. The material can exhibit potential applications as a piezoelectric sensor at 0–20 GPa, high‐pressure actuators ≈20 GPa, and as a high melting temperature resistive substrate for laser welding and cutting materials. [ABSTRACT FROM AUTHOR]