Purpose This study aims to establish an accurate prediction model for nonuniform tool wear in GH4169 milling by integrating process optimization and intelligent learning techniques. Design/methodology/approach A two-stage approach was used: response surface methodology (RSM) optimized cutting parameters, and a Whale Optimization Algorithm-backpropagation (WOA-BP) neural network model was built using machining angle and time to predict localized tool wear. Findings The proposed RSM–WOA-BP model achieved high prediction accuracy, reducing root mean square error to 1.69µm and mean absolute percentage error to 1.14%, significantly outperforming conventional BP networks in robustness and generalization. Research limitations/implications Because the model parameters are closely related to workpiece machinability, coating wear resistance and tool–workpiece contact geometry, significant changes in workpiece material, coating system, tool diameter, cutting-edge geometry or cooling/lubrication strategy may alter the wear mechanism and the angle-dependent load distribution, leading to systematic bias if the model is directly applied. In such cases, recalibration is required. The proposed workflow is transferable to other materials and tool/coating systems, provided that necessary recalibration and validation are conducted under the new conditions. Practical implications In batch manufacturing, the machining parameters and tool type for a given operation are typically kept stable, so the calibration effort can be amortized over the production batch; the model can thus serve as a practical tool for process planning and wear monitoring. Originality/value This work integrates the strengths of RSM and WOA-BP to develop a high-accuracy model for predicting nonuniform tool wear in ball-end milling, ensuring both modeling precision and experimental efficiency. The model supports precise tool wear prediction in machining nickel-based superalloys with ball-end mills, enabling better control of tool life, cost reduction and improved reliability in complex aerospace and high-temperature applications. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2025-0308/

Hard carbon is a leading anode for sodium-ion batteries, but its high-rate operation remains limited by the fragmented optimization of pore structure, interlayer spacing, electronic adsorption, and interphase chemistry. This limitation originates from insufficient attention to multiscale structural coupling. Here, we report a curvature-regulated ion-electron coupling strategy for high-rate hard carbon anodes. Using β-cyclodextrin-assisted molecular confinement carbonization, local carbon curvature is regulated to suppress long-range graphitic stacking while expanding interlayer spacing. The regulated curvature simultaneously lowers Na+ diffusion barriers, shifts the p-band center to optimize Na+ adsorption energetics, and reconstructs an anion-enriched interfacial environment that promotes a thin NaF-rich SEI. The designed structure enables efficient Na+ transport, demonstrating remarkable long-term cyclability with a high-capacity retention of 90.9% after 1000 cycles at 3 A∙g−1 and exceptional rate capability (up to 6 A∙g−1). This concerted structural-electronic dual modulation establishes a novel pathway to decouple the conventional trade-off between capacity and rate performance in hard‑carbon anodes.

Research on protective measures for aerospace service components spans a broad scope. Infrared (IR) lasers exhibit significant military application potential, underscoring the critical need for effective laser protection. Among available materials, tungsten (W) emerges as the preferred choice due to its high melting point and reflectivity. Herein, a theoretical analysis of the IR laser ablation process of W is conducted. The level-set method is adopted to develop a finite element simulation model, capturing temperature evolution, material removal, and gas dissipation dynamics during ablation. Experimental validation clarifies the formation mechanisms of ablation structures and identified optimal laser parameters for subsequent IR laser damage tests. Next, bases on the twotemperature model, a picosecond laser ablation model of W is developed to simulate the electron-lattice temperature dynamics and material removal. Response surface methodology (RSM) is employed to determine laser parameters that optimize microstructural morphology. Finally, comprehensive performance evaluation tests are performed; the protective enhancements of various microstructural arrays are compared. Circular microstructures with arc-bottom are identified as the optimal configuration. Further parametric optimization reveals that arrays with 110 mu m spacing and 40 mu m depth achieved superior protective performance.

Laser-induced periodic surface structures (LIPSS) have attracted considerable attention in micro/nano-optics, sensing, and surface engineering for their ability to generate subwavelength periodic features and functionalize material surfaces. However, their practical application remains limited by challenges in period uniformity, orientation consistency, aspect ratio, and large-area scalability. Focusing on high-quality LIPSS fabrication, the review systematically examines recent progress in fundamental formation mechanisms and corresponding processing strategies, emphasizing the interplay among formation mechanisms, quality bottlenecks, and control approaches. From a mechanistic perspective, the decisive role of Sipe’s electromagnetic theory in period selection, the influence of surface electromagnetic wave (SEW) and surface plasmon polariton (SPP) coupling on orientation control and large-area uniformity, the morphology evolution governed by heat transfer and melt flow coupling, and the contribution of localized near-field coupling to the formation of deep-subwavelength structures are critically discussed. On this basis, five key control factors are identified: the initial scattering state, electromagnetic coupling efficiency, transient carrier dynamics, heat transfer and melt flow coupling, and local field enhancement. In terms of processing strategies, current approaches for high-quality LIPSS fabrication are categorized into three groups, namely pretreatment, beam shaping, and post-treatment, which respectively enable initial boundary regulation, optimization of energy deposition, and refinement of modified regions. Their applicable scenarios, advantages, limitations, and effectiveness in improving key quality metrics, including period uniformity, orientation consistency, aspect ratio, and defect suppression, are compared and analyzed. Finally, the application prospects of LIPSS in micro/nano-optics, sensing, and functional surfaces are discussed, with multiphysics coupling modeling, unified quality evaluation, and data-driven optimization identified as crucial directions for future research. This review is intended to provide a systematic reference for understanding LIPSS formation mechanisms and optimizing high-quality fabrication processes.

Fast-charging sodium-ion batteries require electrolytes capable of overcoming the sluggish Na+ desolvation kinetics at hard carbon interfaces, yet molecular-level solvent design principles that simultaneously regulate solvation strength and interfacial chemistry remain underdeveloped. Here, a molecular engineering strategy is proposed by synergistically coupling electron-deficient coordination chemistry with spatial-configuration modulation to tailor Na+ solvation structures in medium-concentration ether electrolytes. By introducing additional electron-deficient ether oxygen motifs together with branched terminal groups, solvent donor strength and steric constraints are jointly manipulated to weaken Na+–solvent coordination, promote anion participation, and generate a loose solvation sheath with reduced desolvation barriers. This molecular design enables accelerated interfacial kinetics and induces the formation of thin inorganic-rich interphases favorable for fast Na+ transport. As a result, hard carbon anodes deliver markedly enhanced rate capability and stable cycling, while Ah-level pouch cells achieve 138.4 Wh kg−1 with 90.3% capacity retention after 250 cycles at 2 C and maintain operation at 3 C. This work establishes a molecular design principle for regulating solvation chemistry beyond conventional weakly solvating electrolyte design and provides a practical route toward high-power sodium-ion batteries.

With the continuous advancement of performance requirements for aero-engines, the fabrication of film cooling holes on turbine blades has become critical to engine performance. Water-jet guided laser (WJGL) technology, which combines the advantages of water-jet cooling and nanosecond laser ablation, offers a high-precision solution for micro-hole machining in superalloys. However, when machining hollow thin-walled structures, laser penetration can easily cause damage to the opposite wall. To mitigate such penetration-induced damage, this study establishes an acoustic emission (AE)-based metrological approach for ablation depth measurement during WJGL drilling. Spectral subtraction was first applied to reduce acoustic noise and enhance the signal-to-noise ratio of the measurement data. Single-spot ablation tests under varying power levels were then performed to calibrate the effective ablation intensity threshold (55 dB). The time- and frequency-domain processing of AE responses was conducted as quantitative measurement stages to extract traceable parameters correlated with material-removal depth. Based on these parameters, a support vector regression (SVR)-based measurement estimator was developed to determine depth in real time. The results show that this method enables accurate and repeatable depth measurement during WJGL drilling. Furthermore, measuring AE signals during penetration revealed that the signal intensity drops below 50 dB upon complete hole penetration, a characteristic independent of machining parameters. The proposed method provides a reliable means for in-process drilling depth measurement in WJGL, confirming high accuracy and reproducibility.

The extensive coverage of thick ice in polar regions imposes severe constraints on the efficiency and safety of resource extraction, maritime route development, and scientific exploration. However, existing icebreaking techniques are hindered by low operational efficiency, limited environmental adaptability, and poor ecological compatibility, rendering them inadequate for the complex conditions encountered in polar environments. Therefore, a novel underwater icebreaking method that combines laser pretreatment with impact loading is proposed. In this method, multipoint laser irradiation is initially employed to weaken the structural integrity of the ice, thereby facilitating its fragmentation under subsequent impact loading. Ultimately, efficient fracturing of ice up to 20 cm thick is achieved. A thermo-mechanical coupling model characterizing laser-ice interaction within underwater conditions is established. Numerical simulations of the temperature and stress fields under multi-point irradiation are performed. The thermodynamic mechanism by which laser energy weakens the structural integrity of the ice is elucidated. An experimental platform is constructed to validate the proposed method using natural freshwater ice. The influences of multi-point laser irradiation parameters on ice fragmentation performance are systematically investigated. Experimental results indicated that an outward-toinward irradiation sequence significantly enhances the synergy between thermal and mechanical effects, thereby improving icebreaking efficiency. Furthermore, deployment spacing, laser power, and irradiation duration are identified as critical factors influencing the characteristics of ice fragmentation. Finally, the optimal parameter combination for efficient icebreaking is determined to be a deployment spacing of 4 cm, a laser power of 1703 W, and an irradiation duration of 15 s. This work provides theoretical insights and experiential support for the advancement of laser icebreaking technology.

Densifying and thickening electrodes is an effective strategy for improving battery energy density. This strategy necessitates particular attention to electrolyte wetting across the surface into the pore networks of dense-thick electrodes, as the completeness of pore filling with electrolytes critically impacts their performance. Herein, we propose incorporating sodium cholate (SC) into electrodes to enhance electrolyte wetting and promote electrolyte infiltration. The efficacy of this approach is evaluated by using dense-thick LiFePO4 (LFP)/singlewalled carbon nanotube (SWCNT) electrodes that are prepared by vacuum filtration process. The SC adsorbed within LFP/SWCNT electrodes promotes electrolyte infiltration, which facilitates lithium-ion transport, increases the solid/electrolyte interfacial area, and consequently boosts the rate capacity. Surprisingly, the incorporated SC effectively stabilizes the cathode/electrolyte interphase, thereby extending the cycle life of LFP/SWCNT electrodes. The adsorbed SC increases the capacity of 40 mg/cm2 LFP/SWCNT electrode at 0.5 C from 98 mAh/g to 139 mAh/g, and improves capacity retention rate from 60.3 % to 98.7 % after 500 cycles. Furthermore, the SC wetting-enhancement approach has excellent applicability to conventional slurry-cast LFP electrodes, as demonstrated by significant performance improvements after adding 1 wt% SC to slurry-cast 200 mu m-thick LFP/ carbon black (CB) electrodes. This study provides a valuable approach for advancing the practical deployment of dense-thick electrodes in high-energy-density lithium-ion batteries.

SiC ceramic lattice structures (CLSs) have become increasingly popular in engineering applications due to their remarkable specific strength and thermal properties. To investigate their quasi-static compressive mechanical behavior, binder jetting additive manufacturing technology was used to produce various configurations of SiC CLSs, specifically Edge Center Cubic (ECC), Face Center Cubic (FCC) and Gyroid-type triply periodic minimal surfaces, namely the Gyroid-sheet (GSH) and Gyroid-skeletal (GSK). The findings reveal that the GSH configuration exhibits the highest quasi-static compressive strength at similar to 54 MPa. The failure mechanism is characterized by a sequential propagation of damage. Micro-cracking initiates at points of peak tensile stress-specifically, at the nodes or on the strut surfaces. These cracks then extend through the strut cross-section. The failure of a single critical strut redistributes the load to its neighbors, inducing sequential overloading and fracture. This chain reaction ultimately leads to the catastrophic crushing of the entire structure along an inclined shear zone. This research offers valuable insights for optimizing the design and assessing the mechanical performance of SiC CLSs.

During the long-term storage of RDX/HTPB propellants, slow aging frequently occurs, resulting in irreversible alterations such as internal structural distortion, diminished stability, impaired mechanical properties, and sudden changes in the burning rate. In extreme cases, unintended ignition or spontaneous combustion might occur, posing safety hazards during use. A deep understanding of the microscopic decomposition mechanisms of RDX/HTPB propellants is key to ensuring operational stability and reliability. Using the ReaxFF/lg reactive force field, molecular dynamics simulations of the RDX/HTPB propellant aging process at different temperatures were conducted. Changes in the potential energy, species evolution, reaction pathways, and product distribution patterns were analyzed. The MD results indicate that the lower the temperature is, the lower the aging rate. When the temperature exceeds 1000 K, the aging rate exponentially increases with increasing temperature. The aging process begins with the cleavage of N−NO2 bonds in RDX. The reaction products primarily consist of intermediates, final products, and some large carbon-containing clusters. The fitted activation energy was determined to be 85.59 kJ/mol, with a predicted storage life of 23.56 years at 20 °C. The storage life of the propellant is negatively correlated with temperature, indicating that low-temperature environments are beneficial for extending the storage duration of the propellant.

Abstract Edges of two-dimensional (2D) materials are generally more chemically reactive than their basal planes. Accordingly, engineering ultrafine edge architectures in 2D semiconductors is a compelling route to boost surface-enhanced Raman scattering (SERS). This work proposes an approach to enhance SERS sensing by fabricating ultrafine nanogroove array (NGA) structures on 2D multilayer 2H-WS₂ using femtosecond (fs) laser processing. Based on the fs laser-induced surface plasmon polariton-local near-field (SPP-LNF) effect, NGA structures with ultrafine groove widths are successfully fabricated. The processed regions remain a single-crystalline structure and exhibit “sharp” edges free of obvious amorphous or oxide layers, thereby achieving a breakthrough in non-ablation laser processing of 2D material edges. Compared with the unprocessed 2H-WS₂ regions, the NGA regions demonstrate significantly enhanced SERS sensing performance, achieving a detection limit down to 10⁻⁹ mol/L for crystal violet (CV) molecules, which is three orders of magnitude lower than that of pristine 2H-WS₂. Through combined theoretical and experimental analyses, the enhanced SERS performance of the NGA structures is attributed to the more active molecular adsorption at nanostructure edges and the intrinsic defects associated with sharp edges. This work offers a robust strategy for the controllable fabrication of edge structures and high-performance SERS sensing.

To enhance lithium-ion transport and electronic conductivity in Li4Ti5O12 (LTO) electrodes, the synchronous additive-subtractive fabrication based on femtosecond laser strategy is presented. Numerical models for subtractive fabrication through femtosecond laser ablation of LTO-SWCNTs (LTO integrated with single-walled carbon nanotubes) and additive fabrication through single-sided Cu sputtering are developed. Accordingly, synchronous additive-subtractive fabrication is realized on a Cu-electrode-Cu "sandwich" structure. Furthermore, the influence of laser parameters on the morphology of the micro holes and the Cu deposition on the hole walls is systematically investigated. Electrochemical tests demonstrate that the electrode performs optimally with a hole spacing of 80 & micro;m and a Cu deposition of approximately 20 wt%. Under 5 C cycling, the reversible specific capacity of the micro-hole array electrode is enhanced approximately threefold, while the synchronous additivesubtractive fabrication electrode exhibited a nearly sevenfold increase. Additionally, the micro-hole structure enhances the apparent Li-ion diffusion coefficient by approximately four times. The Cu deposition increases the electronic conductivity from 11.8 S center dot m-1 to 18.7 S center dot m-1.

The high brittleness of the ceramic matrix and the high deformability of the carbon fibers pose a challenge for the machining of carbon fiber reinforced ultra-high temperature ceramic (Cf/UHTCs) matrix composites. In this study, Cf/ZrB2-SiC UHTCs are processed by ultra-fast laser to investigate the ablation mechanism, and the ablation thresholds are calculated separately for different parts of the material. Excessive laser energy or repetition frequency will lead to the ablation mechanism changing from photochemical to photothermal. For ceramic matrix, SiC is preferentially removed during machining, followed by the removal of high-density and high melting point ZrB2. Large amounts of vaporized ZrB2 with the ZrO2 melt will form spherical particles. Raman spectroscopy analysis show that with increasing laser energy input, the temperature of carbon fiber increases, and the structural ordering and graphitization degree of the carbon material increased.

When a deep-penetration weld was fabricated by high-energy beam welding, the microstructure and mechanical heterogeneities along the depth direction frequently occurred, which had an adverse effect on the serviceability of the deep-penetration welded nickel-based superalloy components. To address this issue, this study introduces a high-frequency beam oscillation strategy to actively homogenize the microstructure and properties of Inconel 718 joints with depth of penetration exceeding 21 mm fabricated by vacuum laser beam welding. Results demonstrated that oscillation significantly refined the Laves phase. With the increase of oscillating frequency, the content of Laves phase decreased from 6.28 % to 4.07 %, the fraction of large Laves particles (>3.0 mu m) decreased from 9.82 % to below 6.4 % and the secondary dendrite arm spacing was reduced from 4.71 mu m to under 3.85 mu m. This refinement is attributed to Nb element homogenization, which hinders Laves phase formation, and the physically limited growth space within refined secondary dendrite arm spacing. The weld joint with high-frequency beam oscillation showed a more uniform tensile strength with a coefficient of variation of 1.15 % and an average strength of approximately 850.8 MPa. This work provides a novel pathway to tailor the microstructure and mechanical performance for single-pass deep-penetration welding of thick 718 components.

A thick-section GH4169 superalloy joint for safety-critical hot-section components was welded via a novel vacuum laser welding process.This process utilizes a vacuum environment to enhance laser welding penetration ability.The microstructure and mechanical properties of the deep-penetration welded GH4169 superalloy were systematically investigated.The volume fraction of brittle Laves precipitate reached an exceptionally low level due to lower heat input and faster cooling rate involved in vacuum laser beam welding.The results indicated that a more than 17.5 mm-deep defect-free laser weld with a sound weld appearance was prepared.The yield strength and ultimate tensile strength of the weld joint in the as-welded condition were 434.6 and 775.9 MPa,respectively.Post-weld heat treatment promoted the precipitation of γ″ phase,which greatly improved the strength of the joint.

Fabricating high-aspect-ratio micro-holes in thick-walled titanium alloys presents a persistent challenge due to the conflicting requirements of high machining efficiency and superior surface integrity. In this study, a coaxial electrolyte-enveloped laser-electrochemical hybrid tool is proposed to achieve high-efficiency and precision micro-holes fabrication in 40 mm-thick TC4 alloy. This novel configuration delivers laser energy through a multimode fiber waveguide (MFW) while independently supplying electrolyte through an annular channel, ensuring the synchronous coupling of laser irradiation, electrochemical reaction and electrolyte transport. A time-resolved multiphysics model was established to explicitly bridge the temporal gap between nanosecond laser pulses and microsecond electrochemical pulses. Simulations reveal that independent and coaxial delivery significantly improves laser coupling efficiency to 94.2% while enhancing flow uniformity. Experimental results demonstrate that the hybrid process increases the volumetric removal rate by approximately 28.6% compared to electrochemical machining (ECM). Ultimately, a micro-hole with a depth-to-diameter ratio of similar to 30.9 and an average surface roughness of Ra similar to 2.34 mu m was successfully fabricated. These findings validate the feasibility of the proposed hybrid tool for producing high-integrity, recast-layer-free deep micro-holes in difficult-to-cut aerospace materials.

The fabrication of high-aspect-ratio holes in difficult-to-cut alloys frequently suffers from parameter mismatches induced by a deteriorated confined-space flow field environment and an inadequate fundamental understanding of the intricate multi-physics coupling mechanisms, thereby degrading machining efficiency and surface integrity. This remains a primary challenge in laser-ECM hybrid machining. To address these limitations, this work proposes a spatially decoupled hybrid machining technique. By spatially isolating the transmission paths of the laser and the electrolyte, this technique eliminates fluid and bubble interference ahead of the machining gap, which enables higher incident laser energy to be transmitted to the anode surface as a highly concentrated power density. Based on this decoupled configuration, the multi-physics field distribution was reconstructed, elucidating a dynamic transition in the material removal mechanism from laser-assisted dissolution to a laser-ablation-dominated process, thereby systematically revealing the spatiotemporal coupling mechanisms of the multi-physics fields. Furthermore, the results demonstrate that synergistically regulating the inter-electrode gap (IEG) and the inlet flow rate optimizes the mass transfer environment within the gap, effectively mitigating product retention and hydrodynamic instability. This synergistic control of the flow and energy fields enhances the stability of material removal, ultimately enabling the fabrication of high-surface-quality deep blind holes and low-taper, high-aspect-ratio through-hole arrays in TC4 alloy, providing a viable technical approach for the machining of precision aerospace components.

The trend toward integration and miniaturization in modern chips poses a significant challenge to the thermal management of devices. Traditional thermal interface materials can no longer meet the heat dissipation requirements of high-power devices. Utilizing high-thermal-conductivity diamond for microfluidic cooling appears to be a promising solution. In this study, polycrystalline diamond was processed using an infrared picosecond laser system. We investigated the influence of processing parameters on the degree of diamond graphitization, as well as on the dimensions and taper of the fabricated microchannels. By optimizing these parameters to minimize graphitization, low-sidewall-taper (0.9 degrees) diamond microchannels with an aspect ratio of 4:1 and a depth of 800 mu m were successfully fabricated. Furthermore, the effects of different scanning strategies on the bottom surface roughness of the gutter were examined. A gutter with a depth of 800 mu m and a bottom surface roughness of Sa 1.13 mu m was prepared using a cross-scan strategy, and a through-hole with an inlet diameter of 1.1 mm and an outlet diameter of 1 mm was fabricated using a circular-drilling strategy. Ultimately, this work demonstrates the direct fabrication of a complete diamond microchannel heat sink assembly.

Understanding wavelength-dependent electron excitation and energy deposition is essential for clarifying the early stage surface electronic response of 3C-SiC during femtosecond laser processing, but remains poorly understood. In this work, time-dependent density functional theory (TDDFT) is used to study 3C-SiC with femtosecond laser pulses at 13.5, 400, and 1030 nm over a wide intensity range, clarifying how ultrafast electronic excitation may influence the early stage surface electronic response of 3C-SiC. Under 13.5 nm irradiation, the response is dominated by direct high energy interband excitation, causing smooth current evolution and harmonic spectra dominated by the fundamental component. Under 400 and 1030 nm irradiation, increasing intensity induces strong current modulation and spectral broadening, indicating a transition from weak to strong field nonlinear response. Excited electrons and absorbed energies increase with intensity, with weak field scaling reflecting distinct excitation pathways. At 1 & times; 10(13) W/cm(2), 400 and 1030 nm pulses induce pronounced charge redistribution and drive the excited electron density to similar to 10(21) cm(-3), whereas 13.5 nm requires 1 & times; 10(14) W/cm(2). These findings show that medium- and long-wavelength femtosecond lasers more readily drive 3C-SiC toward a high density nonequilibrium electronic regime, suggesting favorable electronic precursor conditions for subsequent transient surface destabilization and electron-lattice energy transfer.

The present study investigates the intrinsic mechanism underlying the changes in surface properties of the aluminum alloy substrate induced by laser cleaning. The experiments were conducted with laser fluences ranging from 1.2 to 8.0 J/cm2. The topography and chemical composition of the laser-cleaned surface were analyzed, the surface wear resistance and micro-hardness were simultaneously measured. The microstructure of the substrate cross-section was characterized after laser cleaning to analyze the underlying mechanism driving performance variations. The paint could be completely removed from the substrate surface at a laser fluence of 3.2 J/cm2 without causing any damage. However, when the laser fluence exceeds 4.8 J/cm2, the surface micro-hardness and wear resistance of the aluminum alloy both decrease, which is caused by the formation of a remelted layer and a heat-affected layer on the substrate. A decrease in dislocation density is observed in the heat-affected layer, while the elemental composition of the aluminum alloy remains unaltered.