Additive manufacturing最新文献

{"title":"Optimizing dimensional accuracy in two-photon polymerization: Influence of energy dose and proximity effects on sub-micrometric fiber structures","authors":"Ianis Drobecq ,&nbsp;Claire Bigot ,&nbsp;Olivier Soppera ,&nbsp;Laurent Malaquin ,&nbsp;Bastien Venzac","doi":"10.1016/j.addma.2025.104735","DOIUrl":"10.1016/j.addma.2025.104735","url":null,"abstract":"<div><div>Two-photon polymerization (2PP) is a powerful technology for achieving sub-micrometric precision in additive manufacturing, enabling the fabrication of 3D fibrillar structures with sub-micrometric fibers. This study provides an extensive study of the parameters that influence the dimensional accuracy of suspended beams, such as energy dose and proximity effects between the surrounding supportive structures and the fibers. Through systematic characterization of these parameters, we analyze the impact of spatial confinement on fiber width, height, and structural stability. Our results reveal that beyond conventional parameters like energy dose, long-range proximity effects induced by oxygen depletion and diffusion significantly influence final feature dimensions. These findings provide insights into optimizing 2PP for high-resolution, reproducible structures, advancing its application in fields where nanoscale precision is essential, such as tissue engineering and photonics.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"103 ","pages":"Article 104735"},"PeriodicalIF":10.3,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143739659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Operando synchrotron X-ray analysis of melt pool dynamics in an Al-Sn immiscible alloy","authors":"Ahmad Zafari ,&nbsp;Sai Pratyush Akula ,&nbsp;Mogeng Li ,&nbsp;Akane Wakai ,&nbsp;Ashlee Gabourel ,&nbsp;Samuel J. Clark ,&nbsp;Kamel Fezzaa ,&nbsp;Ian Gibson ,&nbsp;Atieh Moridi","doi":"10.1016/j.addma.2025.104754","DOIUrl":"10.1016/j.addma.2025.104754","url":null,"abstract":"<div><div>The melt flow in an Al-50vol% Sn immiscible alloy, produced by single-track laser melting of Al and Sn elemental powders, was studied in real time. High-speed synchrotron X-ray imaging was used to track the movements of Al and Sn liquids, and also to examine elemental distributions in the laser tracks, complimented by electron microscopy after solidification. Key aspects, including melt pool geometry, keyhole instability, and flow dynamics (flow pattern and velocity), were examined using digital image analysis. Relatively deeper melt pools formed at 400 W and 300 mm/s exhibited greater stability, with smooth surfaces, consistent outward flow, and minor vortices near the keyhole. In contrast, shallower pools produced at higher scanning speeds (&gt;500 mm/s) demonstrated greater instability with increased surface waviness, and stronger velocity fluctuations, leading to numerous micro-vortices and increased Al-Sn heterogeneity. Velocity scale estimations, supported by experimental observations, examined the roles of vapour pressure, Marangoni effect, buoyancy, inertial, and surface tension forces in the flow. The results revealed that vapour pressure and mechanical waves dominated at high scanning speeds (shallow pools), while Marangoni forces were equally significant in deep pools at lower speeds (300 mm/s). Buoyancy was found to have minimal impact in both cases. Furthermore, the interaction between inertial and surface tension forces played a critical role in determining the degree of waviness of the pools’ surfaces. These findings offer valuable insights into melt pool dynamics during laser processing of immiscible alloys and other metallic systems using elemental powders, and provide guidance for developing high-fidelity computational fluid dynamics models.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"103 ","pages":"Article 104754"},"PeriodicalIF":10.3,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143746946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing laser cladding stability: Defects and schlieren-based analytics during L-DED","authors":"Benedikt Brandau ,&nbsp;Rico Hemschik ,&nbsp;João Paulo Sousa ,&nbsp;Frank Brueckner ,&nbsp;Alexander F.H. Kaplan","doi":"10.1016/j.addma.2025.104758","DOIUrl":"10.1016/j.addma.2025.104758","url":null,"abstract":"<div><div>A schlieren system, adapted for Laser Directed Energy Deposition, was used to monitor and analyze the process zone under various conditions, including deliberate contamination and parameter limits. This approach enabled the identification and correlation of process-induced defects with schlieren phenomena. Events and zones were characterized and qualitative categorized to validate schlieren monitoring as a diagnostic tool. Notably, a highly active and spatially confined schlieren formation was consistently observed above the melt pool. Using a tailored schlieren optical setup and simulations, schlieren patterns were linked to refractive index changes in process gases, enabling quantitative analysis. The refractive index within the hot gas dome over the molten pool was observed to range from 1.00000712 to 1.00875126, with fluctuation speeds reaching up to 210 m/s. As a result, a model was developed to describe the impact of refractive index dynamics on the performance of coaxial monitoring systems in laser processes. A case study using an exemplary imaging monitoring system demonstrated that schlieren phenomena can cause wavelength-dependent lateral geometric shifts of up to 228 µm, significantly affecting the accuracy of object-based monitoring outcomes. The findings offer critical insights into the complex interplay between refractive index variations and monitoring results, paving the way for refined monitoring strategies that enhance reliability and precision in laser cladding applications.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"103 ","pages":"Article 104758"},"PeriodicalIF":10.3,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In-situ multi-eye monitoring of melt pool temperature field in laser additive manufacturing by light field camera","authors":"Xiuhua Li ,&nbsp;Hui Li ,&nbsp;Xuefeng Chen ,&nbsp;Shengnan Shen ,&nbsp;Guodong Zhang ,&nbsp;Huiliang Wei ,&nbsp;Yaowu Hu ,&nbsp;Zhongwei Li ,&nbsp;Linmao Dai","doi":"10.1016/j.addma.2025.104747","DOIUrl":"10.1016/j.addma.2025.104747","url":null,"abstract":"<div><div>Laser direct energy deposition (LDED) and laser powder bed fusion (LPBF) are two typical metal laser-based additive manufacturing (AM) processes used in critical fields such as aerospace and aviation. However, the stability of their part quality remains challenging. The temperature of the melt pool during the AM process significantly influences the quality of the manufactured parts. Therefore, breakthroughs in in-situ monitoring technology for high-temperature, small-area melt pools keep an urgent need. To address this challenge, this paper proposes a multi-eye monitoring method using a light field (LF) camera for in-situ melt pool temperature field monitoring. Initially, a LF sub-aperture Bayer model (LFSBM) is established to extract melt pool images at red, green, and blue (<em>R</em>, <em>G</em>, and <em>B</em>) wavelengths. By calibrating the LF camera’s relative spectral response ratio using the blackbody furnace, the melt pool’s temperature field is derived based on dual-wavelength theory from two images at <em>R</em>, <em>G</em>, and <em>B</em> channels. Linear fitting of the relative spectral response ratio for channel combinations of <em>B</em> and <em>G</em>, <em>R</em> and <em>B</em>, and <em>R</em> and <em>G</em> yielded root mean square errors of 76.34 K, 62.24 K, and 78.66 K, respectively. The mean error for maximum temperature was verified to be 1.03 %, and less than 3 % for temperature filed at temperatures of 2973.15 K, 3073.15 K, and 3273.15 K by the blackbody furnace. The influence of coaxial system of LPBF on wavelength intensity was calibrated. The contour error between the temperature map and the blackbody furnace was found to be less than 1.4 %. Experiments were conducted on high-entropy alloy, and Ti6Al4V alloys manufactured by both LDED and LPBF equipment, and evolution of length, width, and maximum temperature were analyzed. The proposed method simplifies the measurement process and allows for an unlimited temperature range, providing a groundbreaking approach for in-situ melt pool temperature monitoring during the AM process.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"102 ","pages":"Article 104747"},"PeriodicalIF":10.3,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687817","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":"In-situ crosslinked nano SiO2 reinforced alginate bio-textile for mitigating plastic shrinkage in 3D printed concrete","authors":"Kailun Xia ,&nbsp;Yuning Chen ,&nbsp;Zedi Zhang ,&nbsp;Wei Wang ,&nbsp;Yu Chen ,&nbsp;Lutao Jia ,&nbsp;Zijian Jia ,&nbsp;Shitao Quan ,&nbsp;Yamei Zhang","doi":"10.1016/j.addma.2025.104753","DOIUrl":"10.1016/j.addma.2025.104753","url":null,"abstract":"<div><div>Absence of formwork leaves 3D printed concrete (3DPC) with rapid water loss and plastic shrinkage. For water preservation, a strategy based on in-situ generated bio-textile film on 3DPC surface is proposed herein. The conception was achieved by adopting nano SiO₂ (NS) reinforced sodium alginate (NSSA) onto 3DPC surface. Triggered by calcium ions on 3DPC surface, in-situ crosslinking of NSSA can generate a water preservation film, where NS serves as reinforcer for film densification. Moreover, through pozzolanic reaction, NS can induce further crosslinking between C-S-H and alginate biopolymer matrix, forming a bio-textile film with enhanced water vapor impermeability, mechanical property and surface adhesion on 3DPC. Within 3 hours and 24 hours after concrete printing, this strategy significantly reduced 3DPC plastic shrinkage by 74 % and 59 %, and preserved water in 3DPC from evaporation by 72.8 % and 75.4 %. This study provides a promising new approach for mitigating plastic shrinkage of 3DPC.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"102 ","pages":"Article 104753"},"PeriodicalIF":10.3,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704127","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":"Constraint-based form-finding of space trusses for Injection 3D Concrete Printing through Vector-based Graphic Statics","authors":"Yinan Xiao ,&nbsp;Norman Hack ,&nbsp;Harald Kloft ,&nbsp;Dirk Lowke ,&nbsp;Inka Mai ,&nbsp;Pierluigi D’Acunto","doi":"10.1016/j.addma.2025.104751","DOIUrl":"10.1016/j.addma.2025.104751","url":null,"abstract":"<div><div>This paper presents a form-finding approach for Injection 3D Concrete Printing (I3DCP) using Vector-based Graphic Statics (VGS). This approach adopts a top-down strategy, initiating a preliminary global design in the form of a space truss and integrating structural and fabrication constraints specific to I3DCP. A form-dependent self-weight load is applied throughout the form-finding process until the structure achieves static equilibrium. As the current I3DCP setup is mounted on a robotic arm with a stationary base, the feasibility of the designed structure for I3DCP is assessed, ensuring compatibility with the robotic arm’s workspace. Structures exceeding the workspace boundaries are segmented and individually optimised, subject to topological and geometrical constraints. The optimised segments are then merged into a single assembly to complete the process. This approach is demonstrated through the design and construction of a 3-metre-span pedestrian bridge. This prototype is 3D scanned and then analysed via the finite element method to evaluate its mechanical performance.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"103 ","pages":"Article 104751"},"PeriodicalIF":10.3,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143739658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and optimization of high stiffness tetrahedral lattice structure","authors":"Peng Zhang ,&nbsp;Fengxi Bai ,&nbsp;Yi Liu ,&nbsp;Yingxin Ma ,&nbsp;Wei Zeng ,&nbsp;Yi-Jun Yang ,&nbsp;Ligang Liu ,&nbsp;Weiming Wang","doi":"10.1016/j.addma.2025.104719","DOIUrl":"10.1016/j.addma.2025.104719","url":null,"abstract":"<div><div>As tetrahedra are well known for their stability and excellent load-bearing capabilities, this work proposes a novel method for designing and optimizing high-stiffness tetrahedral lattice structures. First, the tetrahedral lattice cells with periodic boundary conditions are generated within a unit cubic domain based on a specified number and radii of randomly distributed seed points. By analyzing the printability of the lattice cell, several constraints are introduced to restrict both the number of seed points and their radii within each lattice cell. Next, the relationships among the number of seed points, radii, relative density, Young’s modulus, and anisotropy of the lattice cells are analyzed using the homogenization method. For a given design domain, it is discretized into a hexahedral finite element mesh. A topology optimization formulation is then proposed to optimize the number of seed points and their radii across all finite elements. The seed points are randomly sampled within each finite element according to the optimized number and radius. Finally, a strut-shaped tetrahedral lattice with variable radii is generated based on the seed points and their radii. Additionally, a strategy is introduced to eliminate struts in low-density regions to further enhance structural stiffness. Extensive numerical and physical experiments, along with comparisons, have been conducted to demonstrate the effectiveness of the proposed method.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"102 ","pages":"Article 104719"},"PeriodicalIF":10.3,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704126","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":"Inducing inter-filament fusion during embedded 3D printing of silicones","authors":"Leanne M. Friedrich,&nbsp;Jeremiah W. Woodcock","doi":"10.1016/j.addma.2025.104741","DOIUrl":"10.1016/j.addma.2025.104741","url":null,"abstract":"<div><div>Embedded 3D printing (EMB3D) is an additive manufacturing technique that enables fabrication of soft materials including silicones and biological tissues. In EMB3D, a nozzle is embedded in a viscoelastic support bath and writes continuous filaments. Because the bath takes care of form holding, inks that are not printable using conventional extrusion methods can be printed using EMB3D. However, EMB3D can experience defects including positioning errors, poor inter-filament fusion, shrinkage, and rupture. Here, we use in-situ imaging experiments to investigate how defects evolve while disturbing pairs of filaments and writing triplets of filaments. By comparing written triplets to disturbed pairs, we isolate whether defects come from writing of subsequent filaments or from nozzle movement alone. Using silicone-based inks printed into water-based supports with varying concentrations of rheological modifier and surfactant, we probe how the balance between interfacial tension and viscous dissipation governs both inter-filament fusion and capillary instabilities. Critically, higher interfacial tensions and lower support viscosities lead to more rupture, more shrinkage, and more inter-filament fusion. Running the nozzle next to unfused pairs of filaments can cause fusion, but it can also cause rupture. The microstructure of the ink can also influence defects, as phase separation can inhibit both inter-filament fusion and rupture. In addition to material properties, the toolpath also controls defect formation. Fusion quality varies depending on whether filaments are horizontal or vertical in the bath, and whether filaments are stacked on top of each other or next to each other. Moreover, considerable overlap is necessary to achieve inter-filament fusion, leading to over-extrusion. Toolpaths should consider the positioning defects that come from this over-extrusion, particularly vertical displacement of horizontal lines. This work provides key guidelines to achieve prints with better shape fidelity, better resolution, and improved mechanical properties.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"102 ","pages":"Article 104741"},"PeriodicalIF":10.3,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687764","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":"Flexible lattice structure using curved struts based on body-centered cubic structure","authors":"Takashi Sasagawa,&nbsp;Naruhiko Nimura,&nbsp;Masato Tanaka","doi":"10.1016/j.addma.2025.104746","DOIUrl":"10.1016/j.addma.2025.104746","url":null,"abstract":"<div><div>Mono-material design is effective for achieving sustainability and a circular economy. Conversely, most industrial products are manufactured using a diverse range of materials to introduce multifunctional properties and characteristics. To resolve this trade-off, a wide range of mechanical properties can be achieved by controlling the porous cellular structures using a single material. For instance, Young’s modulus can be modified by changing the relative density of the cellular structures. However, in the case of 3D printed components, the lower limit of the relative density depends on the dimensional accuracy that can be achieved. Therefore, a novel flexible lattice structure is proposed to increase the range of mechanical property control. The key aspect of our lattice structure is the realization of slender and tilted struts by curving the struts of a conventional lattice structure. Consequently, the resulting structures exhibited approximately 40 times greater flexibility than body-centered cubic and octet truss lattices at the same relative density. Furthermore, Young’s modulus and static energy absorption values were achieved over a range of approximately three orders of magnitude by controlling the relative density from 13.3% to 100% for our lattice.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"103 ","pages":"Article 104746"},"PeriodicalIF":10.3,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724346","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":"Strategic layer reworking using hybrid additive manufacturing for defect-free ceramic parts","authors":"Louis Masters ,&nbsp;Dan Davie ,&nbsp;Pablo J. Cevallos ,&nbsp;Matthew P. Shuttleworth ,&nbsp;Daniel Bara ,&nbsp;James Warren ,&nbsp;Mehmet Dogar ,&nbsp;Robert Kay","doi":"10.1016/j.addma.2025.104752","DOIUrl":"10.1016/j.addma.2025.104752","url":null,"abstract":"<div><div>Hybrid manufacturing combines additive and subtractive processes to create parts of high precision and density. However, extrusion-based processes are susceptible to stochastic defects such as voids, which lower yield and worsen material properties, leading to premature failure of components. This research demonstrates deep learning informed selective layer reworking for a ceramic hybrid additive manufacturing platform. We evaluate each layer in-situ for under and over extrusions using a vision-based monitoring system and a YOLOv8 model trained on a custom dataset. Through closed-loop control, a decision to repair defective layers via subtractive operations, prior to reprinting, was made using conditional gcode programming based on the results of the YOLOv8 model. The YOLOv8 model detected voids with a precision of 91 %, and a mean average precision of 83.5 % across both defect classes. Through CT analysis, it was determined that reworking achieved a 68 % reduction in void content compared to uncorrected parts, showcasing the potential of hybrid manufacturing in the creation of defect-free parts.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"102 ","pages":"Article 104752"},"PeriodicalIF":10.3,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143696149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}