Additive manufacturing最新文献

{"title":"In-situ controller autotuning by Bayesian optimization for closed-loop feedback control of laser powder bed fusion process","authors":"Barış Kavas ,&nbsp;Efe C. Balta ,&nbsp;Michael R. Tucker ,&nbsp;Raamadaas Krishnadas ,&nbsp;Alisa Rupenyan ,&nbsp;John Lygeros ,&nbsp;Markus Bambach","doi":"10.1016/j.addma.2025.104641","DOIUrl":"10.1016/j.addma.2025.104641","url":null,"abstract":"<div><div>Laser powder bed fusion (LPBF) additive manufacturing (AM) traditionally relies on static parameter assignment in an open loop, which can lead to defects when faced with complex thermal histories and process variability. Closed-loop control offers a promising alternative that can enhance stability and mitigate defects. However, controller performance relies heavily on precise parameter tuning, a process that is typically manual and system-specific. This study employs Bayesian Optimization (BO) as an automated, sample-efficient method for tuning in-layer controllers in LPBF, leveraging the repetitive nature of the process for either online (in-process) or offline (pre-process) tuning. We experimentally apply BO to tune an in-layer PI controller to modulate laser power, assessing its performance on wedge geometries prone to overheating. The results show that BO significantly reduces overheating, outperforming uncontrolled settings. Notably, this study presents the first microstructural analysis of parts produced with in-layer controlled tuning, identifying lack-of-fusion porosities caused by the controller’s corrective adjustments. In summary, BO demonstrates strong potential for automated controller tuning in LPBF, with implications for broader applications in AM, suggesting a path towards more adaptive and robust control across diverse machines and materials.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"99 ","pages":"Article 104641"},"PeriodicalIF":10.3,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137308","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":"Microstructure tailoring for crack mitigation in CM247LC manufactured by powder bed fusion – Laser beam","authors":"Ahmed Fardan ,&nbsp;Andrea Fazi ,&nbsp;Jakob Schröder ,&nbsp;Tatiana Mishurova ,&nbsp;Tobias Deckers ,&nbsp;Giovanni Bruno ,&nbsp;Mattias Thuvander ,&nbsp;Andreas Markström ,&nbsp;Håkan Brodin ,&nbsp;Eduard Hryha","doi":"10.1016/j.addma.2025.104672","DOIUrl":"10.1016/j.addma.2025.104672","url":null,"abstract":"<div><div>Tailored microstructures in powder bed fusion – laser beam (PBF-LB) can aid in crack mitigation of non-weldable Ni-base superalloys such as CM247LC. This study explores the effect of a range of stripe widths from 5 mm down to 0.2 mm to control solidification cracking, microstructure, and residual stress in CM247LC manufactured by PBF-LB. The decrease in melt pool depth with the reduction in stripe width from 5 to 0.2 mm promoted the &lt; 100 &gt; crystallographic texture along the build direction. The crack density measurements indicated that there is an increase from 0.62 mm/mm² (5 mm) to 1.71 mm/mm² (1 mm) followed by a decrease to 0.33 mm/mm² (0.2 mm). Atom probe tomography investigations at high-angle grain boundaries revealed that there is higher Hf segregation in 0.2 mm stripe width when compared to 5 mm. This indicates that the cracking behavior is likely influenced by the grain boundary segregation which in turn is dependent on melt pool shape/size and mushy zone length indicated by accompanying simulations. Residual stress, measured by X-ray diffraction, decreased from 842 MPa (5 mm) to 690 MPa (1 mm), followed by an abnormal rise to 842 MPa (0.7 mm) and 875 MPa (0.5 mm). This residual stress behavior is likely associated with the cracks acting as a stress relief mechanism. However, the 0.2 mm stripe width exhibited the lowest stress of 647 MPa, suggesting a different mechanism for stress relief, possibly due to re-melting. These findings highlight the critical role of stripe width as a scan strategy in PBF-LB processing of crack-susceptible alloys.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"99 ","pages":"Article 104672"},"PeriodicalIF":10.3,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137445","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":"Multicell interlacing IWP lattice metamaterials with superior low-frequency vibration isolation performance fabricated by laser powder bed fusion","authors":"Mengying Chen ,&nbsp;Di Lin ,&nbsp;Lei Yang ,&nbsp;Cong Zhang ,&nbsp;Hui Qiao ,&nbsp;Lei Kang ,&nbsp;Liu He ,&nbsp;Yunlong Ren ,&nbsp;Chunze Yan ,&nbsp;Yusheng Shi","doi":"10.1016/j.addma.2025.104681","DOIUrl":"10.1016/j.addma.2025.104681","url":null,"abstract":"<div><div>Lattice metamaterials have been proven to be effective for vibration reduction and isolation, but they do not perform well in the low-frequency bands. In this work, inspired by traditional Chinese Taoist concept, multiple IWP-type TPMS lattices are interlaced with each other to achieve low-frequency vibration isolation. The normal IWP lattice (NIL), double interlacing IWP lattice (DIIL), and quadruple interlacing IWP lattice (QIIL) are designed and prepared by the laser powder bed fusion (LPBF) technique. The frequency response and vibration isolation performance of the TPMS lattice metamaterials are analyzed through the dynamic vibration testing and shaft system vibration testing, respectively. The results reveal that the multicell interlacing IWP lattice metamaterials have better low-frequency vibration isolation performance than body centered cubic (BCC) and normal IWP lattices. With the increase of the interlacing-cell number, IWP lattice metamaterials have a better vibration isolation effect in the low-frequency band. Notably, the 316 L QIIL metamaterials have superior vibration isolation performance with the maximum vibration level difference of 47.44 dB. This study offers a new perspective for the application of lattice metamaterials in low-frequency vibration reduction and isolation.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"99 ","pages":"Article 104681"},"PeriodicalIF":10.3,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137892","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 detailed study of pre-heating effects in electron beam melting powder bed fusion process","authors":"E. Landau ,&nbsp;Y.I. Ganor ,&nbsp;D. Braun ,&nbsp;M. Strantza ,&nbsp;M.J. Matthews ,&nbsp;E. Tiferet ,&nbsp;G. Ziskind","doi":"10.1016/j.addma.2025.104656","DOIUrl":"10.1016/j.addma.2025.104656","url":null,"abstract":"<div><div>Metal-based additive manufacturing processes, such as powder bed fusion with electron beam (PBF-EB) process, also referred to as electron beam melting (EBM), can produce high-density parts with minimal residual stresses due to the uniform and coherent preheating of the powder bed. However, understanding and controlling the multiple stages of preheating is required to enable the production of high-quality, consistent parts of various materials. This work presents a large-scale, multi-layer, three-dimensional numerical analysis focused on studying the preheating stages for predicting thermal history during the PBF-EB process. The model follows a continuous multi-stage cyclic process, that incorporates all the main stages of the PBF-EB process for 316 L stainless steel. This includes the gradual deposition of a new powder layer, the first and second preheating levels of the powder bed, and the energy deposition during melting (excluding the actual melt-pool behavior simulation). The model employs an adaptive time-scaling approach that automatically adjusts the energy deposition for each solution time-increment. This allows for localized changes in time-resolution over an otherwise computationally expensive multi-layer procedure. The material property variations are also taken into account, with an emphasis on the subtle irreversible changes in powder effective thermal conductivity after the two requisite preheating stages of the powder bed. This effect is studied using simplified conductivity models from the literature for partially sintered powder, validated by a dedicated experiment and numerical simulation. The large-scale model is then used to estimate the actual temperatures during first and second preheating levels for 316 L steel, which is not yet fully supported commercially for PBF-EB. Model predictions are corroborated by experiments, using and analyzing IR images, taken at the completion of each layer by the machine’s built-in infrared camera. The current model also incorporates a qualitative assessment for the effects of conductivity change during pre-heating, as well as evaluates the applicability of the time-scaling approach.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"99 ","pages":"Article 104656"},"PeriodicalIF":10.3,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137444","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":"Ti2AlNb microlattices via 3D ink-extrusion printing and sintering of precursor powders","authors":"Ya-Chu Hsu,&nbsp;David C. Dunand","doi":"10.1016/j.addma.2025.104673","DOIUrl":"10.1016/j.addma.2025.104673","url":null,"abstract":"<div><div>Microlattices are 3D-extruded with inks containing a blend of precursor Ti + Nb + TiAl₃ powders, and their struts are then densified through a series of heat treatments to eliminate organic binder, sinter porosity, and achieve compositional Ti₂AlNb homogeneity. The phase evolution of an as-printed filament (representative of a microlattice strut) is examined using <em>in-situ</em> X-ray diffraction, revealing a series of steps: (i) TiAl₃ decomposition, starting at 710 °C and ending at 780 °C, to form TiAl; (ii) Nb and Al interdiffusion, initiating at 820 °C, accompanied by the formation of Nb₂Al and Nb₃Al phases; (iii) the α→β Ti phase transformation and (iv) Ti₃Al formation, starting at 870 °C. Fully-homogenized Ti₂AlNb microstructures with low residual porosity, comprising a B2 matrix and two types of α₂ and O (orthorhombic) secondary phases, are achieved after sintering at 1300 °C for 5 h. Under compression at 1000 °C, microlattices with struts ∼400 µm in diameter show a good combination of yield strength (138 MPa) and ductility (48 %, with no catastrophic failure). Because of their low density (∼3 g/cm³) and high strength at high temperatures, Ti₂AlNb microlattices exhibit a specific strength higher than existing Ni- and Co-based superalloy microlattices above 900 °C. Finally, a complex Ti₂AlNb prototype heat exchanger is created <em>via</em> layer-by-layer ink-extrusion and sintering.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"99 ","pages":"Article 104673"},"PeriodicalIF":10.3,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137894","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":"Structured, sintered, and rastered strategies for fluid wicking in additively manufactured heat pipes","authors":"Cameron Noe ,&nbsp;Swapnil Morankar ,&nbsp;Alexander S. Rattner ,&nbsp;Alexander Potts ,&nbsp;Zachary Goode ,&nbsp;Tatiana El Dannaoui ,&nbsp;John R. Sherbondy ,&nbsp;Nikhilesh Chawla ,&nbsp;William Sixel ,&nbsp;Sven Bilén ,&nbsp;Stephen Lynch ,&nbsp;Chad Westover ,&nbsp;Dhruv Bhate","doi":"10.1016/j.addma.2025.104669","DOIUrl":"10.1016/j.addma.2025.104669","url":null,"abstract":"<div><div>This work compares three different strategies for creating wicking structures with Laser Powder Bed Fusion (LPBF) for use in additively manufactured monolithic heat pipes: (i) structured wicks, fabricated with intentionally designed lattice geometries, (ii) sintered wicks, created by partially melting and fusing the metal powder used in the LPBF manufacturing processes, and (iii) rastered wicks, created by modifying the laser raster infill grid parameters to generate fluid flow paths. The study was performed in three phases. Phase I examined wick fluid absorption, porosity, volumetric energy density, and wick manufacturability for a broad range of production parameters. A subset of promising wick production approaches was identified for fluid rate-of-rise characterization in Phase II. One high performing wick production approach was selected for each strategy for detailed characterization in Phase III. In this last phase, the wick candidates were studied through X-ray microtomography, scanning electron microscope (SEM) imaging, porosity analysis, and computational simulations of directional sample permeability and thermal conductivity (using geometry data from X-ray imaging). Advantages and disadvantages of each wick design approach were explored in the context of both manufacturability using LPBF, and wick performance. Of the three strategies, the rastered approach was found to have the most potential for applications in future additively manufactured heat pipe designs due to its wide LPBF manufacturability process window and its relatively high permeability with low directional dependence.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"99 ","pages":"Article 104669"},"PeriodicalIF":10.3,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137446","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":"The mirror additive manufacturing process for tool-less fabrication of continuous carbon fiber reinforced thermoplastic resin matrix composite","authors":"Tianhao Zhao,&nbsp;Leyan Chen,&nbsp;Kenan Zhang,&nbsp;Haihang Wang,&nbsp;Jie Yang,&nbsp;Qinglong An,&nbsp;Ming Chen,&nbsp;Jingwei Zhang","doi":"10.1016/j.addma.2025.104680","DOIUrl":"10.1016/j.addma.2025.104680","url":null,"abstract":"<div><div>A mirror additive manufacturing (MAM) process has been proposed, in which dual mutually supported robotic heads simultaneously perform placement and in-situ laser heating curing of thermoplastic prepreg tapes. This approach overcomes the reliance on complex tools in conventional processes, enhancing manufacturing flexibility, cost-efficiency and production efficiency as well as the applicability to special environments such as space, remote areas and disaster zones. The severe instability of temperature and rolling force during the MAM process was effectively addressed by the proposed control strategy combining reinforcement learning with a PID algorithm. Moreover, ply-by-ply decrease in temperature is caused as the cumulative heating effect of the mirror heat sources weakens with the rise of laminate thickness, which is precisely compensated by the proposed temperature stabilization control method, enabling stable temperatures across each ply. Compared with the open-loop MAM system, the stabilization control of temperature and rolling force significantly improves surface quality, reduces internal defects and enhances macro-mechanical performance. The effect of process parameters such as laser power, rolling force and placement speed on surface roughness, internal defects and macro-mechanical characteristics has also been clarified.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"99 ","pages":"Article 104680"},"PeriodicalIF":10.3,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137907","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":"Self-generating multiscale configurations, their CAD features in support of 3D printing and their CAE efficiencies","authors":"Qirui Jin ,&nbsp;Chuang Ma ,&nbsp;Yichao Zhu","doi":"10.1016/j.addma.2025.104670","DOIUrl":"10.1016/j.addma.2025.104670","url":null,"abstract":"<div><div>Additive manufacturing enables the production of a number of multiscale configurations such as lattice structures. However, due to their multiscale complexities, the acquisition of explicit, high-fidelity, resource-saving digital description of lattice configurations is still technically challenging. This article is aimed to introduce a general algorithm for digital presentation of lattice structure, whose constituting cells can be spatially-varying. The natural suitability of the present algorithm with additive manufacturing can be summarised as follows. Firstly, the designed lattice here can be represented fully in line with Computer-Aided Design (CAD) conventions. Secondly, the designed lattice can functionally approximate any multiscale configurations in the sense of resulting in similar responding fields under given loading conditions. Thirdly, the designed lattice can be digitally memorised in a highly compact manner, and an unzipping scheme in parallel with its additive manufacturing process is thus proposed to maintain the number of CAD control points in memory at a low level. Fourthly, mechanical properties of the designed lattice, both its overall compliance and its localised properties, such as its strength, can be evaluated instantly, with the use of a machine-learning-based asymptotic homogenisation and localisation method.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"99 ","pages":"Article 104670"},"PeriodicalIF":10.3,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137909","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":"Thin-plate lattices in AlSi10Mg alloy via laser additive manufacturing: Highly enhanced specific strength and recovery","authors":"Jordan Noronha,&nbsp;Jason Dash,&nbsp;David Downing,&nbsp;Mahyar Khorasani,&nbsp;Martin Leary,&nbsp;Milan Brandt,&nbsp;Ma Qian","doi":"10.1016/j.addma.2025.104664","DOIUrl":"10.1016/j.addma.2025.104664","url":null,"abstract":"<div><div>Metallic lattices have emerged as a class of lightweight, strong, and multifunctional materials with growing applications. However, their specific strengths (strength-to-density ratios) often fall significantly short of those of their bulk metal counterparts. Thin-plate lattices (TPLs), featuring submillimeter-thick metal plates, present a promising solution. Yet, traditional manufacturing methods have long hindered their development. This study investigates laser additive manufacturing and the mechanical properties of axially isotropic AlSi10Mg alloy TPLs, designed with various unit cells, including cubic, cuboctahedron, truncated-octahedron, rhombicuboctahedron, and sphere structures. With densities ranging from 0.57 to 1.13 g/cm³ , these TPLs achieved exceptional specific yield strengths up to 90 % of the base alloy—significantly surpassing the performance of strut-based metallic lattices, which typically achieve 50–60 %. Additionally, under uniaxial compression, the TPLs demonstrated remarkable near-complete peak stress recovery, even at high strain levels (&gt;50 %) or during fragmentation, offering a unique safety mechanism. This recovery was driven by distinct failure modes: at lower densities, fractures progressed layer by layer, leaving intact layers, while at higher densities, crack deflection enhanced resilience. These findings position TPLs as a transformative advancement, combining exceptional specific strength with robust recovery characteristics to outperform conventional lattice designs in multifunctional, high-performance applications.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"99 ","pages":"Article 104664"},"PeriodicalIF":10.3,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137910","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":"Modeling and spatio-temporal optimization of grayscale digital light processing 3D-printed structures with photobleaching resins","authors":"Xiru Fan ,&nbsp;Mengjie Zhang ,&nbsp;Liguo Hu ,&nbsp;Le Dong ,&nbsp;Qinghua Yu ,&nbsp;Biao Zhang ,&nbsp;Kun Zhou ,&nbsp;Dong Wang","doi":"10.1016/j.addma.2025.104659","DOIUrl":"10.1016/j.addma.2025.104659","url":null,"abstract":"<div><div>Grayscale digital light processing (DLP) 3D printing modulates light intensity in each pixel through grayscale values, offering a promising approach for achieving high-resolution printed structures. However, existing theoretical models and optimization methods typically rely on the assumuption of a photo-invariant resin, for simplification. This study demonstrates that the curing depth varies even when the total accumulated dose remains constant, indicating a photo-variant effect. To address this, a spatio-temporal optimization method along with a model are developed, incorporating photobleaching effects, multilayer exposure, and Gaussian beam propagation. The model accurately predicts variations in curing depths at constant doses. Structures are optimized using this model, resulting in several significant improvements: channel heights are reduced to approximately one-fifth of the empirical minimum value with variations below 10 %; concave lenses are optimized with smooth surfaces; and the stair-stepping effect is notably reduced. Additionally, an asymmetric stair-stepping effect is identified between the left and right sides of objects printed at the corner, primarily caused by light divergence. The developed model and spatio-temporal optimization algorithm pave the way for high-fidelity grayscale DLP 3D printing.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"99 ","pages":"Article 104659"},"PeriodicalIF":10.3,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137440","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}