International Journal of Machine Tools & Manufacture最新文献

{"title":"Quasi-in-situ reconstruction and regulating mechanism of plastic flow in steel friction stir welding","authors":"Yuxuan Li ,&nbsp;Mingrun Yu ,&nbsp;Shikang Gao ,&nbsp;Guangda Sun ,&nbsp;Haitao An ,&nbsp;Li Zhou","doi":"10.1016/j.ijmachtools.2025.104341","DOIUrl":"10.1016/j.ijmachtools.2025.104341","url":null,"abstract":"<div><div>Resolving the mystery of plastic flow in steel friction stir welding (FSW) is critical for process. However, constrained by limitations in flow field techniques and insufficient understanding of the underlying physics, a holistic understanding of plastic flow and its regulating mechanism remains largely empirical. In this study, the material response to the mechanical processing of the FSW tool is reconstructed through a quasi-continuous observation technique. The mechanism of cavity filling, the effective range of tool-workpiece contact states, and the real-time boundary of the shear layer are analyzed. At finer scales, multiple independent vertical components are identified, inducing either unstable periodic flow or mass-balancing effects. These components are characterised as vortex structures. Accordingly, a dynamic model is proposed to specifically elucidate the formation of local vortex structures. The model uses tool–workpiece interaction as the basis for a qualitative description to assess the location of vortex activation, a process that can be semi-quantitatively represented through finite element simulations. The dynamic evolution of the vortex is attributed to the constraining effect of solid-state boundaries on the flow field. The real-time boundary of the shear layer is considered as one form of solid-state boundary, whose constraining effect promotes localised vortex formation. Specifically, the formation of captured vortexes is defined based on the assumption of tool-workpiece interaction and the delineation of shear layer boundaries. Model adaptability is preliminarily verified, and a low-cost method is proposed for capturing previously hidden plastic flows. Across a wide range of process parameters, this model effectively explains plastic flow behaviour. These analyses not only advance a comprehensive knowledge of flow dynamics and associated shear behaviour in steel FSW, but also demonstrate that the proposed dynamic model deepens the fundamental understanding of the complex physical mechanisms during the process. Therefore, this study lays a foundation for optimising welding parameters and supports future academic investigations focused on plastic flow or shear behaviour control.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"213 ","pages":"Article 104341"},"PeriodicalIF":18.8,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145247950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights into hydrodynamic self-balancing mechanics in adaptive float machining process for nanometric form error control","authors":"Fang Han,&nbsp;Jingyuan Wang,&nbsp;Wei Gao,&nbsp;Shuai Wang,&nbsp;Bingchun Jia,&nbsp;Cao-Yang Xue,&nbsp;Weijian Zhang,&nbsp;Bing-Feng Ju,&nbsp;Wule Zhu","doi":"10.1016/j.ijmachtools.2025.104333","DOIUrl":"10.1016/j.ijmachtools.2025.104333","url":null,"abstract":"<div><div>With advances in semiconductor and aerospace industries, the demand for components with atomic and close-to-atomic scale accuracy is paramount. As a non-contact method, float machining is showing great potential for excellent surface finishing, where the adaptive fluid film between the tool and workpiece plays an essential role. However, its dynamic self-balancing mechanics remains unexplored, without revealing which, the outcome of extreme accuracy could be hardly touched or controlled. To address this issue, a hydrodynamic coupling dataset driven hydrodynamic model with in-situ force-position sensing approach is proposed. This work presents the first systematic elucidation of the transient processes governing the fluid film-tool interaction as the system achieves a balancing state. Simulation and experiments were conducted to demonstrate the adaptive film evolution route, and its relation to the specific process conditions with precise prediction. Insights into the intermediate states and inherent self-balancing mechanism enable exceptional form control ability, namely deterministic removal of 3 nm in depth across an arbitrary 3 mm region. Subsequently, a sinusoidal hyperbolic freeform with form error within ±2 nm PV over a 5 mm region was fabricated using only a stepper-motor platform, and the underlying process produces an atomically ordered, damage-free subsurface. Furthermore, the capability for non-uniform machining was verified by fabricating compound-eye structures and correcting curved surfaces to nanometric form accuracy.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"212 ","pages":"Article 104333"},"PeriodicalIF":18.8,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145096895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel in-situ field-assisted powder bed laser fusion using liquid metal enabling microstructure control and strength enhancement of austenitic steel","authors":"Xiaoyu Liang ,&nbsp;Yurong Wang ,&nbsp;Wei Liu ,&nbsp;Buwei Xiao ,&nbsp;Qingze Liu ,&nbsp;Yizhuo Sun ,&nbsp;Pengcheng Lv ,&nbsp;Huabei Peng ,&nbsp;Jun Zhou ,&nbsp;Lei Zhang ,&nbsp;Feng Lin","doi":"10.1016/j.ijmachtools.2025.104334","DOIUrl":"10.1016/j.ijmachtools.2025.104334","url":null,"abstract":"<div><div>The layer-by-layer powder bed additive manufacturing approach, which encapsulates the workpiece in powder during processing, imposes limitations on the integration of in-situ field assistance and enhances production costs. In this work, a novel laser powder bed fusion has been proposed in which the layer-wise accumulated powder bed is replaced by a thin powder layer floating on the liquid Sn. Such a liquid-metal-assisted laser powder bed fusion presents unique advantages: the characteristic thermal history of deposited materials due to high thermal conductivity and fluidity of liquid metals provides greater possibilities for microstructure modulation; the recyclable liquid metal also reduces the need for powder in the forming cylinder and reduces the number of times the powder is reused. Based on the normalized process diagram of liquid-metal-assisted laser powder bed fusion, forming experiments were carried out on the austenitic stainless steels, and the mechanisms underlying the regulation of fine-grain regions were investigated, along with an analysis of the microstructure of this region. Results indicated that the high cooling rate during liquid-metal-assisted laser powder bed fusion led to a finer microstructure and a heterogeneous grain structure ranging from submicron to micron scales in the austenitic stainless steels. The formed heterogeneous austenitic steel exhibits a yield strength surpassing 1.1 GPa and a tensile strength of 1.5 GPa, while retaining an average uniform elongation of 7 %. The in-situ heat treatment principles using liquid metal demonstrated in this work have significant applicability across various additive manufacturing processes and precipitation-hardening alloys.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"212 ","pages":"Article 104334"},"PeriodicalIF":18.8,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The typical cellular microstructures developed in powder-based additively manufactured metallic materials: formation mechanisms, properties, outlooks and challenges","authors":"Jianying Wang ,&nbsp;Heng Li ,&nbsp;M.W. Fu","doi":"10.1016/j.ijmachtools.2025.104332","DOIUrl":"10.1016/j.ijmachtools.2025.104332","url":null,"abstract":"<div><div>Cellular microstructures are intrinsically associated with the printability and mechanical-functional performance of laser-additively manufactured metallic materials. An in-depth understanding of formation mechanisms under extreme processing conditions and impacts on mechanical-functional performance remains critical to improving the application prospects of laser additive manufacturing. In this paper, vital insights into the characteristics, formation mechanisms, mechanical-functional performance, and prospects of cellular microstructures are orchestrated and articulated. First, the differences between dislocation cellular microstructures obtained from conventional methods and those induced by additive manufacturing are summarised through a comparative analysis. Based on the diverse environments of sub-boundaries, almost all cellular microstructures in metallic materials are then exemplified and classified into three categories: dislocation-formed cellular microstructures, both with and without elemental segregation, and eutectic-formed cellular microstructures. For each category, its formation mechanisms related to analysis approaches and evaluation of mechanical-functional performance are delineated and discussed in detail. Finally, insights into the formation mechanisms, model development, thermal stability of cellular microstructures, and countermeasures for aspects of their negative influence on printability and performance are presented. Collectively, this systematic review of cellular microstructures provides a foundational framework to guide the design, manufacture, and industrial-scale implementation of high-performance metallic components.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"212 ","pages":"Article 104332"},"PeriodicalIF":18.8,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Manufacturing limit and structural scale effect of thin-wall/rod units in lattice structure fabricated by laser powder bed fusion","authors":"Qiao Zhong,&nbsp;Mengxiao Jin,&nbsp;Shihao Bie,&nbsp;Liying Meng,&nbsp;Yisong Wang,&nbsp;Kaiwen Wei,&nbsp;Jiapei Liu,&nbsp;Jianqiang Gong,&nbsp;Yu Yang,&nbsp;Anqi Ouyang,&nbsp;Xiangyou Li,&nbsp;Xiaoyan Zeng","doi":"10.1016/j.ijmachtools.2025.104323","DOIUrl":"10.1016/j.ijmachtools.2025.104323","url":null,"abstract":"<div><div>The growing maturity of additive manufacturing (AM) technologies, represented by laser powder bed fusion (LPBF), has greatly facilitated the design and manufacturing of lattice structure. However, the process constraints of the minimum features (thin-wall/rod units) in lattice structure remains poorly understood. This study investigated the manufacturing limits and the relevant failure mechanism of thin-wall/rod units fabricated by LPBF. The effects of structural scale (dimension and inclination angle) on surface morphology, microstructure, and mechanical properties were also studied. Results indicate that the failure of thin-wall/rod units at critical dimension and inclination angle was driven by interlayer molten track mismatch and warping effect in cantilever region, respectively. AM process simulations reveal that rod unit exhibit better manufacturability at small inclination angles compared to thin-wall unit, due to less significant stress deformation. A clear dependence of defect behavior, surface morphology and microstructural characteristics on structural scale is identified. A multi-physics model was created to observe the development of down-skin surface quality of the thin-wall units at small inclination angles. Microstructural analysis reveals transitions between super-refined equiaxed grains, millimeter-long columnar grains, and centimeter-long columnar grains at different scale governed by temperature gradient and grain competitive mechanisms. Additionally, a declining tendency in tensile strength is detected with decreasing feature dimension and inclination angle, primarily because the poor side surface quality and higher porosity accelerated crack initiation and propagation. Moreover, two types of lattice structures were fabricated accordingly. Their characterization results confirm the applicability of the new findings from thin-wall/rod unit experiments, providing insights for the efficient manufacturing of lattice structures endowed with excellent performance.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"212 ","pages":"Article 104323"},"PeriodicalIF":18.8,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144989499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Derivation of physical equations for high-speed laser welding using large language models","authors":"Kyubok Lee ,&nbsp;Zhengxiao Yu ,&nbsp;Zen-Hao Lai ,&nbsp;Peihao Geng ,&nbsp;Teresa J. Rinker ,&nbsp;Changbai Tan ,&nbsp;Blair Carlson ,&nbsp;Siguang Xu ,&nbsp;Jingjing Li","doi":"10.1016/j.ijmachtools.2025.104320","DOIUrl":"10.1016/j.ijmachtools.2025.104320","url":null,"abstract":"<div><div>It is challenging to formulate complex physical phenomena that occur in a manufacturing process, particularly when the available data are limited, rendering conventional data-driven approaches ineffective. This study aims to predict humping onset in high-speed laser welding by introducing a novel framework, namely text-to-equations generative pre-trained transformer (T2EGPT). This method leverages the capabilities of large language models (LLMs), in combination with sparse experimental data and enriched literature data, to derive an interpretable and generalizable equation for predicting humping initiation. By capturing key correlations among physical parameters, T2EGPT generates a compact and dimensionless expression that accurately predicts hump formation. The equation reveals that humping arises from the interplay between inertia-driven backward melt flow and capillary-driven surface stabilization, where inertial forces drive molten metal backward and capillary forces resist surface deformation. Compared to traditional data-driven models, T2EGPT demonstrates enhanced predictive accuracy and cross-material transferability. More broadly, this study highlights the potential of LLMs to integrate textual information with data-driven discovery, enabling the extraction of physical laws in data-scarce scientific domains.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"211 ","pages":"Article 104320"},"PeriodicalIF":18.8,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144892072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrafast laser plasma dynamics enabled ultrafine vertical nanochannel array in transparent materials","authors":"Taijin Wang ,&nbsp;Lingfeng Wang ,&nbsp;Feng Liu ,&nbsp;Gary J. Cheng","doi":"10.1016/j.ijmachtools.2025.104322","DOIUrl":"10.1016/j.ijmachtools.2025.104322","url":null,"abstract":"<div><div>The direct fabrication of vertical nanochannels with ultrahigh aspect ratios (1000:1) in transparent materials has long been hindered by diffraction-limited focal spots and plasma-induced instabilities inherent to conventional ultrafast laser processing. To address these challenges, we introduce a dynamic focusing homogenized light field technique, which integrates a high-refractive-index optical medium to compress the laser focal spot below the diffraction limit (∼700 nm) while leveraging nonlinear Kerr effects to elongate the axial energy distribution. This approach dynamically redistributes energy spatiotemporally, suppressing plasma explosion pressures by 86 % (1440 nm vs. 192 nm) and enabling deterministic control over nanochannel geometry. Through dual-temperature equation simulations and time-resolved plasma spectroscopy, we establish a predictive framework linking processing parameters—such as cover glass thickness, pulse width, and energy—to nanostructure dimensions, achieving aspect ratio close to 1000:1, exemplified by nanochannels measuring 182 μm in length and 192 nm in width. Key innovations of this technique include nonlinear focal drift engineering, which decouples transverse resolution from longitudinal energy deposition, and a plasma suppression mechanism informed by numerical simulations and spectroscopy, ensuring structural integrity through multi-dimensional light field control. Furthermore, we demonstrate the first single-step fabrication of 3D volumetric diffraction gratings in fused silica with sub-1.25 μm channel spacing and tailored optical responses, such as 35.9 % diffuse transmittance and a 0.52 absorption coefficient at 247 nm. This method transcends traditional trade-offs, offering precision, scalability, and versatility: it achieves sub-100 nm feature control, enables scalable fabrication of complex architectures like through-hole and multi-depth structures, and tailors optical properties for metamaterials in integrated photonics, nanofluidics, and quantum optics. By resolving plasma-driven instability and thermal accumulation, our technique unlocks transformative applications in low-loss waveguides, single-molecule sensors, and topological photonic crystals. This work redefines laser nanofabrication as a universal platform for high-precision, scalable 3D structuring in brittle materials, positioning it as a cornerstone for next-generation optical and quantum technologies.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"211 ","pages":"Article 104322"},"PeriodicalIF":18.8,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144896640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Review of physicochemical-assisted nanomanufacturing processes for wide-bandgap semiconductor wafers","authors":"Kazuya Yamamura ,&nbsp;Hui Deng ,&nbsp;Yasuhisa Sano ,&nbsp;Junji Murata ,&nbsp;Xu Yang ,&nbsp;Rongyan Sun","doi":"10.1016/j.ijmachtools.2025.104321","DOIUrl":"10.1016/j.ijmachtools.2025.104321","url":null,"abstract":"<div><div>Nanomanufacturing involves not only fabricating nanoscale three-dimensional microstructures but also achieving nanoscale surface planarization and smoothing—an indispensable requirement in semiconductor-wafer processing. Wide-bandgap semiconductors such as SiC, GaN, diamond, and AlN combine high hardness, brittleness, and chemical inertness, making it exceptionally difficult to produce large size wafers with damage-free, atomic-level smoothness that meets the performance demands of next-generation devices. Physical–chemical composite methods, which marry the high-efficiency planarization of mechanical removal with the damage-free of chemical reactions, have emerged as the most promising route to overcome this challenge. Chemical mechanical polishing (CMP), the first-generation composite technique, was well established in industry; however, its low material removal rates, extensive consumable use, and environmental burden were increasingly problematic as wafer sizes grow and new wide-bandgap materials become mainstream. This review surveys the principal physicochemical processing techniques and examines four representative approaches—plasma-assisted polishing (PAP), plasma-based atomic-selective etching (PASE), catalyst-assisted etching (CARE), and electrochemical mechanical polishing (ECMP). A systematic comparison of their mechanisms, advantages, and limitations clarifies how these methods maintain crystal integrity while enabling selective material removal, thereby delivering atomically smooth surfaces with significantly higher throughput. The review provides both theoretical insight and practical guidance for cost-effective, atomically precise processing of wide-bandgap semiconductor wafers.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"211 ","pages":"Article 104321"},"PeriodicalIF":18.8,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144840819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel strategy for electrochemical additive manufacturing: Femtosecond laser-assisted localized electrochemical deposition","authors":"Zhaoqiang Zou ,&nbsp;Wanfei Ren ,&nbsp;Jinkai Xu ,&nbsp;Hanhan Wei ,&nbsp;Zhanjiang Yu ,&nbsp;Ningqian Tang ,&nbsp;Huadong Yu","doi":"10.1016/j.ijmachtools.2025.104319","DOIUrl":"10.1016/j.ijmachtools.2025.104319","url":null,"abstract":"<div><div>Localized electrochemical deposition (LECD) exhibits significant advantages in fabricating microscale 3D metallic structures. However, conventional LECD technologies are inherently constrained by diffusion-controlled mechanisms, where pursuit of enhanced deposition efficiency inevitably degrades deposition quality (such as increased surface roughness and internal defects), consequently impairing structural mechanical properties. This study presents a femtosecond laser-assisted localized electrochemical deposition (FsLA-LECD) technology. By precisely coupling femtosecond laser irradiation with the electrodeposition microzone and leveraging laser energy to regulate electrodeposition process, this approach simultaneously achieves efficient fabrication of complex metallic microstructures with enhanced mechanical performance. The regulating effects of laser irradiation on mass transfer, nucleation kinetics, and grain growth evolution are investigated throughout the evolution process of point-surface-structure. Experimental and computational analysis elucidate that the laser-induced Marangoni effect within the reaction microenvironment enhances microzone electrolyte replenishment, consequently elevating deposition current density. This results in a volume deposition rate of 15.47 μm³/s, representing a 3 times enhancement over laser-free conditions. Laser-mediated regulation of deposition rates enabled fabrication of uniform-diameter, bamboo-like, and hourglass-shaped microstructures. Furthermore, pulsed laser energy facilitated stepwise current amplification, thereby inducing nanotwin formation within copper micro-geometrical features. This approach attained a tensile yield strength of 1.08 GPa, significantly surpassing that of traditional electrodeposited counterparts. This work demonstrates the capability of FsLA-LECD to simultaneously enable high-efficiency manufacturing and enhanced mechanical properties, establishing the groundwork for innovative approaches to high-performance micromanufacturing.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"211 ","pages":"Article 104319"},"PeriodicalIF":18.8,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144827311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the surface polishability and hardness-softening mechanisms of martensitic mould steel in multi-mode nanosecond laser polishing","authors":"Erju Liu ,&nbsp;Donghe Zhang ,&nbsp;La Han ,&nbsp;Zhikun Liu ,&nbsp;Debin Shan ,&nbsp;Bin Guo ,&nbsp;Jie Xu","doi":"10.1016/j.ijmachtools.2025.104311","DOIUrl":"10.1016/j.ijmachtools.2025.104311","url":null,"abstract":"<div><div>Laser polishing is an efficient, reliable, and environmentally friendly surface-finishing technique aimed at improving the surface quality. However, its application to martensitic mould steel is limited by surface-softening issues induced by the pronounced thermal effects of conventional continuous-wave laser polishing. This study proposes a multi-mode nanosecond laser polishing approach that employs a millimetre-diameter beam with top-hat energy distribution to mitigate the thermal effects and alleviate surface softening. A key challenge is achieving high-quality polishing at shallow melting depths. Further, the proposed process may alter the surface-softening mechanism when considering the unique phase-transformation behaviour of martensitic mould steel. To clarify these aspects, the characteristics of multi-mode nanosecond laser polishing, related to the process and properties, are investigated via finite-element simulations and experiments. The results demonstrate that, unlike the multi-directional melt flow induced by the intense melt pool reaction in continuous-wave laser polishing, multi-mode nanosecond laser polishing drives long-range horizontal melt flow and simultaneously induces multiple convex peaks to fill concave valleys, thereby achieving high-quality surface smoothing (Sa = 0.23 μm) with a minimal melting depth (&lt;2 μm). Moreover, a novel surface-softening mechanism involving the synergistic induction of residual austenite enrichment (up to 90 %) in the fusion zone and martensite tempering effects in the heat-affected zone is presented, which contrasts with the traditional mechanism that relies solely on tempering-induced softening in the heat-affected zone. This study presents a low-thermal-effect, high-quality, and high-efficiency polishing solution for metal components, while advancing the theoretical understanding of hardness-softening mechanisms in the laser manufacturing of martensitic steel.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"211 ","pages":"Article 104311"},"PeriodicalIF":18.8,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}