Additive manufacturing最新文献

{"title":"Local-lattice distortion enables remarkable high-temperature strength and ductility in a Nb-based refractory alloy fabricated by laser powder bed fusion","authors":"Jie Ding,&nbsp;Kaiju Lu,&nbsp;Yanbo Zhang,&nbsp;Kaixin Wang,&nbsp;Xu Li,&nbsp;Jugan Zhang,&nbsp;Jie Wang,&nbsp;Yongjiang Huang,&nbsp;Xiubing Liang","doi":"10.1016/j.addma.2026.105404","DOIUrl":"10.1016/j.addma.2026.105404","url":null,"abstract":"<div><div>Laser powder bed fusion (LPBF) of Nb-based refractory alloys offers a promising route for fabricating geometrically complex high-temperature structural components. However, the simultaneous achievement of excellent LPBF processability, strength, and plasticity remains a critical challenge. Here, we propose a V-induced local-lattice distortion strategy that synergizes with the unique structural control of the LPBF process to develop a novel LPBF-processable Nb-10W-5V alloy with low solidification cracking susceptibility. The LPBF-fabricated Nb-10W-5V alloy exhibits a yield strength of ~625<!--> <!-->MPa and ultimate tensile strength of ~739<!--> <!-->MPa at room temperature, representing over a 50% increase in yield strength compared with previously reported Nb-based alloys. More importantly, through V alloying, the alloy retains a high yield strength of ~261<!--> <!-->MPa and a remarkable fracture elongation of ~15.1% at 1200 °C. This alloy demonstrates comparable strength and significantly enhanced ductility (by 48%) at 1200 °C to typical carbide-strengthened Nb521 alloys, despite the absence of conventional carbide reinforcement. TEM investigations indicated a high density of long and straight screw dislocations as stable deformation carriers at 1200 °C, suggesting suppressed dynamic recovery behavior. First-principles calculations further demonstrated that V-induced local lattice distortion, charge-density redistribution, and d-orbital hybridization increase the lattice friction stress, whereas relatively low unstable stacking-fault energies on multiple slip planes facilitate dislocation nucleation and glide. These findings establish V-induced local-lattice distortion engineering as an effective method for developing LPBF-processable, strong and ductile Nb-based refractory alloys for extreme high-temperature applications.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"130 ","pages":"Article 105404"},"PeriodicalIF":11.3,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149214323","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":"Large-scale extrusion-based additive manufacturing of high-temperature resistant thermoplastic composites","authors":"Olivier Duchesne,&nbsp;Mathieu Verville,&nbsp;Nika Sojoudi Asli,&nbsp;Félix Auger,&nbsp;Kambiz Chizari,&nbsp;Rouhollah Farahani,&nbsp;Frédérick P. Gosselin,&nbsp;Daniel Therriault","doi":"10.1016/j.addma.2026.105412","DOIUrl":"10.1016/j.addma.2026.105412","url":null,"abstract":"<div><div>Additive manufacturing (AM) by material extrusion of high-temperature resistant reinforced thermoplastics offers new design possibilities for large-scale aerospace structures, where production volume is low and mechanical requirements are high. To fill the need for a manufacturing method to make a complex lunar rover frame, we demonstrate by Fused Filament Fabrication (FFF) the rapid large-scale manufacturing of carbon fiber-reinforced polyether ether ketone (CFR-PEEK) composite structures featuring a variable sandwich panel core thickness and an optimized cellular distribution using a custom printing infrastructure. To achieve this main objective, we first determined the appropriate printing parameters from CFR-PEEK flexural beam specimens printed at various combination of nozzle temperature and printing speed. The highest apparent flexural modulus of <span><math><mo>∼</mo></math></span>9.4 GPa and the highest apparent flexural strength of <span><math><mo>∼</mo></math></span>220 MPa were achieved using a nozzle temperature of 440 °C and a nozzle motion speed of 50 mm/s. The best set of parameters also yielded the lowest porosity content of <span><math><mo>∼</mo></math></span>2% interbead and <span><math><mo>∼</mo></math></span>10% intrabead. Using the previously determined printing parameters, we compared the shear strength of three types of sandwich panels: fully printed panels, hybrid panels (printed core bonded to continuous CFR-polyaryl ether ketone (PAEK) facesheets), and a benchmark panel with a nomex® honeycomb core bonded to the same PAEK facesheets. Although the specific ultimate shear strength of the hybrid panels in the honeycomb configuration is <span><math><mo>∼</mo></math></span>4.6 times lower than that of the nomex® honeycomb core, the proposed method enables the fabrication of larger cores in a single process, with the capability for graded structures. The implementation of large-scale CFR-PEEK structures could find applications in the aerospace field, where mass reduction of complex geometries is critical for mission success.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"131 ","pages":"Article 105412"},"PeriodicalIF":11.3,"publicationDate":"2026-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149330750","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":"Re-defining continuous inkjet (CIJ) toward free-form manufacturing","authors":"Sang Hyeon Park,&nbsp;Thanh Huy Phung,&nbsp;Kye-Si Kwon","doi":"10.1016/j.addma.2026.105405","DOIUrl":"10.1016/j.addma.2026.105405","url":null,"abstract":"<div><div>While drop-on-demand (DoD) inkjet printing has been widely adopted in printed electronics, bio printing, and additive manufacturing, continuous inkjet (CIJ) printing remains largely confined to package marking. This study addresses this limitation by developing a programmable free-form CIJ printing framework based on synchronized droplet charging and electrostatic droplet steering, with experimental validation of conductive pattern formation on planar and non-planar substrates. To enable free-form pattern generation beyond conventional marking, raster- and vector-based patterning algorithms were developed for bitmap reproduction and motion-path-based deposition on planar, stepped, and curved surfaces. A customized CIJ printing system was developed, enabling the fabrication of stable, high-fidelity patterns using both an environmentally friendly model fluid and conductive Ag nanoparticle (Ag NP) ink. Using a nozzle with an inner diameter of 60 <span><math><mrow><mi>μ</mi><mi>m</mi></mrow></math></span>, commercial conductive patterns with a deposited dot diameter of approximately 330 <span><math><mrow><mi>μ</mi><mi>m</mi></mrow></math></span> were printed. A single-pass printed conductive line, formed by overlapping successively deposited droplets on a glass substrate, exhibited a resistivity of <span><math><mrow><mn>8</mn><mo>.</mo><mn>9</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>6</mn></mrow></msup><mi>Ω</mi><mo>∙</mo><mi>cm</mi></mrow></math></span>, approximately 5–6 times higher than the bulk resistivity of silver. In addition, printed Ag pads with a thickness of approximately 1 <span><math><mrow><mi>μ</mi><mi>m</mi></mrow></math></span> achieved a sheet resistance of <span><math><mrow><mn>0</mn><mo>.</mo><mn>126</mn><mspace></mspace><mi>Ω</mi><mo>∙</mo><mi>sq</mi><mi>⁻</mi><mi>¹</mi></mrow></math></span> on glass after sintering. These results demonstrate the feasibility of CIJ printing as a versatile, low-cost, single-nozzle manufacturing platform for printed electronics and advanced functional material deposition.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"130 ","pages":"Article 105405"},"PeriodicalIF":11.3,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149364321","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":"Bridging step-edges and cross-surface geometries via aerosol jet printing with a 45° angled nozzle for conformal electronics","authors":"Zhenxiang Xiong,&nbsp;Ziwu Chen,&nbsp;Ao Li,&nbsp;Yingjie Niu,&nbsp;Wenao Ye,&nbsp;Ye Wu,&nbsp;Xin Shen,&nbsp;Shenyao Liu,&nbsp;Chenglin Yi,&nbsp;Hui Cheng,&nbsp;Kaifu Zhang","doi":"10.1016/j.addma.2026.105399","DOIUrl":"10.1016/j.addma.2026.105399","url":null,"abstract":"<div><div>Aerosol jet (AJ) printing is a promising additive manufacturing technique for fabricating high-resolution functional structures; however, conventional straight-nozzle configurations require strict orthogonal alignment between the nozzle and substrate, limiting their applicability for conformal patterning step-edges and cross-surface geometries. In this work, a single 45° angled nozzle is proposed to enable robust and angle-insensitive AJ printing across vertical, inclined, and cross-planar surfaces without the need for nozzle tilting or additional multi-axis motion systems. The gas flow and particle transport characteristics of the angled nozzle are systematically investigated using computational fluid dynamics (CFD) simulations, combined with experimental validation of deposition morphology and electrical performance. The results reveal that substrate inclination modifies the horizontal near-wall flow and consequent deposition geometry, yet leaves the vertical direction virtually unchanged. Process parameters, including nozzle-to-substrate distance, carrier gas flow rate, and focusing ratio, are shown to significantly influence line morphology by modulating particle focusing and dispersion behavior. Experimental results demonstrate that stable and continuous conductive traces can be achieved over a wide range of substrate inclinations, with only minor variations in electrical resistivity. Furthermore, the proposed nozzle configuration is successfully applied to cross-surface interconnects, conformal temperature sensors, and heating structures inside confined geometries, demonstrating its capability for functional device fabrication on step-edges and cross-surface geometries. This study provides a general and practical strategy for simplifying toolpath design and enabling conformal AJ printing in complex 3D environments, thereby expanding the applicability of AJ printing in advanced additive manufacturing and printed electronics.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"130 ","pages":"Article 105399"},"PeriodicalIF":11.3,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149364231","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 continuous homogenization strategy via layer-synchronized induction heating during and subsequent to laser directed energy deposition","authors":"Yeongcheol Shin,&nbsp;Junmyoung Jang,&nbsp;Jeongbin Ahn,&nbsp;Martin Byung-Guk Jun,&nbsp;Seung Hwan Lee","doi":"10.1016/j.addma.2026.105409","DOIUrl":"10.1016/j.addma.2026.105409","url":null,"abstract":"<div><div>During the laser directed energy deposition (LDED) of Inconel 718 (IN718), the brittle Laves phase is formed and degrades the creep resistance of the deposit by acting as a crack initiation site. To address this issue, inhibiting Laves phase formation during deposition or dissolving Laves phase through furnace homogenization heat treatment after deposition has been employed. However, even when the Laves phase formation is inhibited, remaining Laves phase degrades creep resistance. In addition, furnace homogenization induces recrystallization, transforming directionally solidified columnar grains into equiaxed grains that exhibit lower creep resistance than columnar grains. This study proposed a novel strategy that performs continuous homogenization during and subsequent to the LDED process using layer-synchronized induction heating (<span>L</span>-SIH). The deposit was homogenized in situ using an induction coil that was moved upward in synchronization with layer-by-layer deposition during <span>L</span>-SIH LDED, and subsequent induction homogenization dissolved the remaining Laves phase, thereby eliminating the need for a furnace. During the <span>L</span>-SIH LDED, continuous epitaxial grain growth across the interlayer fusion boundaries resulted in a columnar grain structure directionally solidified along the building direction. In addition, recrystallization was suppressed during continuous induction homogenization, thus preserving the directionally solidified columnar grain texture. The Laves-free deposit with a directionally solidified texture, fabricated by <span>L</span>-SIH LDED and subsequently subjected to induction homogenization, exhibited a longer creep life and higher creep elongation than the conventional LDED deposit subjected to furnace homogenization. Furthermore, the precipitation and dissolution mechanisms of secondary phases and the recrystallization behavior of grains in the <span>L</span>-SIH LDED were investigated.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"130 ","pages":"Article 105409"},"PeriodicalIF":11.3,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149364234","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":"Structural evolution of additively manufactured 316L+TiC metal matrix composites during heat treatment revealed by in-situ neutron diffraction","authors":"Geli Fan,&nbsp;Maoxuan Feng,&nbsp;Kazi Nosheen Ava,&nbsp;Seohyeon Jo,&nbsp;Dunji Yu,&nbsp;Ke An,&nbsp;Di Lin,&nbsp;Qiong Nian,&nbsp;Wonmo Kang,&nbsp;M.A. Roldan,&nbsp;Yan Chen,&nbsp;Minglei Qu","doi":"10.1016/j.addma.2026.105400","DOIUrl":"10.1016/j.addma.2026.105400","url":null,"abstract":"<div><div>Additively manufactured (AM) metal matrix composites (MMCs) exhibit enhanced mechanical properties but often retain highly non-equilibrium structures. Understanding how their structure evolves during heating is critical for assessing high-temperature stability and designing heat treatments to further improve performance. Here, we employ <em>in-situ</em> neutron diffraction to investigate the structural evolution of AM 316L + 5%TiC MMCs during heating to 1100 °C and during isothermal annealing at 700 °C. Combined with TEM, particle–matrix stress interaction modeling and thermodynamic modeling, we quantitatively elucidate the temperature-dependent evolution and underlying mechanisms of key structural changes, including thermal misfit stress relaxation, chemical redistribution, phase precipitation, and dislocation evolution. The results show that supersaturated Ti and C in the γ-Fe matrix trigger TiC precipitation at ~540 °C. Upon further heating, two distinct chemical exchange pathways between γ-Fe and fine TiC precipitates are identified: (i) an abrupt compositional recovery from the as-printed, non-equilibrium state at ~700 °C, and (ii) a gradual equilibrium chemical adjustment at higher temperatures. In contrast to monolithic AM 316L, where dislocation recovery begins at ~526 °C, TiC particles in AM 316L + TiC stabilize dislocations up to 742 °C. These combined effects lead to an approximately twofold increase in hardness of 316L + 5%TiC compared to 316L after heat treatment at 700 °C. This study provides quantitative insights into the structural evolution of AM MMCs during heating, offering critical guidance for designing heat treatments to optimize performance for diverse applications.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"130 ","pages":"Article 105400"},"PeriodicalIF":11.3,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149214113","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":"Decoupled in situ auxiliary-laser surface heating for low-stress laser powder bed fusion","authors":"Chuanpeng Du,&nbsp;Huiliang Wei,&nbsp;Qingyuan Yin,&nbsp;Runnan Zhao,&nbsp;Chenyang Lin,&nbsp;Haolin Liu,&nbsp;Nan Kang,&nbsp;Tingting Liu,&nbsp;Wenhe Liao","doi":"10.1016/j.addma.2026.105394","DOIUrl":"10.1016/j.addma.2026.105394","url":null,"abstract":"<div><div>Severe thermal cycling and steep temperature gradients during laser powder bed fusion (LPBF) readily induce residual stress accumulation, leading to cracking, warping, geometric instability, and even premature process termination. These problems remain a critical barrier to the high-quality fabrication of complex metallic components. To address this challenge, we propose a novel low-stress LPBF fabrication strategy enabled by decoupled in situ surface heating using a near-infrared laser auxiliary energy field (AEF). The uniqueness of this strategy lies in its localized, directional, and process-synchronous thermal regulation of the powder bed, providing a new route for controlling residual stress evolution without modifying the primary melting process. A representative octagonal horizontal overhang structure was selected as a challenging validation geometry to systematically examine the mechanism and effectiveness of the proposed method. The results showed that the AEF directionally preheated the local powder bed during the early stage of fabrication, reduced the transient temperature difference between the molten pool and surrounding cold region, reduced the temperature gradient and cooling rate, and prolonged the residence time in the medium-to-high temperature range. These coupled effects suppressed thermal stress generation and promoted high-temperature stress relaxation, thereby alleviating continuous residual stress accumulation. Consequently, interfacial cracking, warping propagation, and geometric instability were effectively mitigated. This work presents a unique in situ thermal regulation paradigm and provides new insight into low-stress LPBF of complex metallic structures.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"130 ","pages":"Article 105394"},"PeriodicalIF":11.3,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149364233","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":"Acoustic emission signatures of crack formation in aluminium-based alloys processed by laser powder bed fusion: Embedded representation learning toward real-time in situ detection","authors":"Denys Y. Kononenko,&nbsp;Dmitry Chernyavsky,&nbsp;Mikhail Seleznev,&nbsp;Lukas Beyer,&nbsp;Anja Weidner,&nbsp;Julia Kristin Hufenbach,&nbsp;Jeroen van den Brink,&nbsp;Konrad Kosiba","doi":"10.1016/j.addma.2026.105408","DOIUrl":"10.1016/j.addma.2026.105408","url":null,"abstract":"<div><div>Additive manufacturing (AM) of dense metallic materials faces challenges from defects such as pores and cracks, especially detrimental to structural performance. In situ crack detection is therefore essential for reliable, defect-free manufacturing. We present a semi-supervised machine learning pipeline for in situ crack detection via acoustic emission (AE) monitoring during laser powder bed fusion (PBF-LB/M) of AA2024. Three specimens fabricated at different process conditions yielded near-fully dense, crack-dominated, and porosity-dominated microstructures. Post-build X-ray computed tomography, optical microscopy, and EBSD provide ground-truth characterization of the defect populations and crack formation mechanism. EBSD identifies the likely microstructural origin of the acoustic signal: solidification cracks propagate intergranularly along high-angle grain boundaries (HAGBs), whose lower density in the dense specimen explains its reduced crack susceptibility. The burst-type AE signal reflects liquid-film rupture at HAGBs and subsequent crack propagation. High-frequency structure-borne AE signals were continuously recorded and analyzed via a three-step pipeline: autoencoder-based embedding of AE events, unsupervised clustering for crack identification, and a lightweight multi-layer perceptron (MLP) classifier for real-time-capable labeling. Spectrogram-based embeddings yield the most reliable crack-noise separation, and an MLP with only 105 parameters achieves a mean F₁-score of 0.93 under stratified, class-weighted cross-validation against HDBSCAN-derived labels, compared to 0.19 for a linear baseline. Jointly trained on AA2024 and Al₉₂Mn₆Ce₂ (at%) data, the pipeline separates crack and noise events despite distinct cracking mechanisms, indicating a shared physical crack signature rather than alloy-specific features. The pipeline is lightweight and computationally real-time-capable, supporting a path toward closed-loop PBF-LB/M process control.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"130 ","pages":"Article 105408"},"PeriodicalIF":11.3,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149364323","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":"Ultra-thin-walled TPMS pure nickel porous lattices via vat photopolymerization of a nickel sulfate precursor","authors":"Hongyuan Wen,&nbsp;Shuai Chang,&nbsp;Mingchuan Li,&nbsp;Jianfeng Gong,&nbsp;Zihao Zhang,&nbsp;Qishun Wang,&nbsp;Liqun Li,&nbsp;Jun Ding","doi":"10.1016/j.addma.2026.105386","DOIUrl":"10.1016/j.addma.2026.105386","url":null,"abstract":"&lt;div&gt;&lt;ul&gt;&lt;li&gt;&lt;span&gt;•&lt;/span&gt;&lt;span&gt;&lt;div&gt;Nickel sulfate enables VPP fabrication of complex thin-walled Ni G-TPMS structures.&lt;/div&gt;&lt;/span&gt;&lt;/li&gt;&lt;li&gt;&lt;span&gt;•&lt;/span&gt;&lt;span&gt;&lt;div&gt;NiS was identified as an intermediate phase during NiSO₄ thermal conversion.&lt;/div&gt;&lt;/span&gt;&lt;/li&gt;&lt;li&gt;&lt;span&gt;•&lt;/span&gt;&lt;span&gt;&lt;div&gt;RS-1250 achieves 99.6 wt% Ni with only 0.0060 wt% residual sulfur.&lt;/div&gt;&lt;/span&gt;&lt;/li&gt;&lt;li&gt;&lt;span&gt;•&lt;/span&gt;&lt;span&gt;&lt;div&gt;RS-1250 exhibits 34.92 MPa UCS and 306% higher normalized modulus than Ni foam.&lt;/div&gt;&lt;/span&gt;&lt;/li&gt;&lt;/ul&gt;&lt;/div&gt;&lt;div&gt;&lt;div&gt;Vat photopolymerization (VPP) enables the fabrication of complex metal structures with high dimensional accuracy. However, strong ultraviolet absorption and scattering by metal powders limit the curing capability of metal slurries, while excessive exposure energy density can induce overcuring and dimensional deviation. Here, nickel sulfate precursor powder was introduced into a VPP process to fabricate thin-walled nickel structures with reduced curing requirements. Nevertheless, the metallization mechanism of nickel sulfate precursors remains unclear. In this study, thin-walled Gyroid triply periodic minimal surface (G-TPMS) porous structures were successfully fabricated using nickel sulfate-based VPP slurries. By analyzing phase evolution, surface chemical states, particle morphology, and microstructural development, we clarified the transformation sequence of NiSO₄ into metallic Ni via NiS and NiO intermediate phases during three-stage heat treatment. The formation of NiS was identified as a key intermediate reaction associated with carbonaceous species generated from resin decomposition. After reduction sintering at 1250 °C, the RS-1250 sample achieved 99.6 wt% Ni, with carbon and sulfur contents of 0.0034 wt% and 0.0060 wt%, respectively. The sample exhibited an average grain size of 121.4 μm, a wall thickness of 62 ± 5 μm, a UCS of 34.92 MPa, and a normalized modulus (&lt;em&gt;E&lt;/em&gt;&lt;sub&gt;N&lt;/sub&gt;) of 107.2 MPa, representing a 306% increase compared with nickel foam. This work demonstrates the feasibility of nickel sulfate precursors for VPP fabrication of thin-walled metallic structures and reveals the sulfur-involved metallization mechanism of sulfate-based precursors.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;Vat photopolymerization (VPP) enables the fabrication of complex metal structures with high dimensional accuracy. However, strong ultraviolet absorption and scattering by metal powders limit the curing capability of metal slurries, while excessive exposure energy density can induce overcuring and dimensional deviation. Here, nickel sulfate precursor powder was introduced into a VPP process to fabricate thin-walled nickel structures with reduced curing requirements. Nevertheless, the metallization mechanism of nickel sulfate precursors remains unclear. In this study, thin-walled Gyroid triply periodic minimal surface (G-TPMS) porous structures were successfully fabricated using nickel sulfate-based VPP slurries. By analyzing phase evolution, surface chemi","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"130 ","pages":"Article 105386"},"PeriodicalIF":11.3,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149214112","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":"Laser absorption and transient thermal behavior in multi-laser wire-powder directed energy deposition of metal matrix composites","authors":"Audai A. Al-Akailah,&nbsp;Yulin Liu,&nbsp;Fuda Ning","doi":"10.1016/j.addma.2026.105407","DOIUrl":"10.1016/j.addma.2026.105407","url":null,"abstract":"<div><div>Multi-laser coaxial wire-powder directed energy deposition (CWP-DED) enables high-rate fabrication of metal-matrix composites (MMCs), yet quantitative links among powder delivery, laser absorption, powder capture, and transient thermal response remain poorly quantified. This work develops an integrated, physics-based reduced-order framework that couples feeder-prescribed SiC powder delivery, Monte Carlo Lagrangian particle transport, beam-resolved Beer-Lambert-Mie attenuation, Fresnel-based absorption partitioning, and transient finite-element heat conduction, implemented here for six-laser SS316L/SiC deposition. The framework resolves absorbed power among the powder, wire, and substrate/build surfaces and maps it into layer- and track-resolved volumetric heat input using temperature-dependent composite properties informed by measured powder catchment efficiency (PCE). Powder-induced attenuation was modest, accounting for approximately 3~6% of the post-optics power, and was insensitive to interparticle restitution, whereas surface absorption dominated the energy partitioning. As deposition transitioned from the A36 substrate to the SS316L/SiC composite surface, predicted total power utilization increased from 37.4~38.4% to 40.6~43.9%. Across five processing conditions, the final adjusted model reproduced substrate-embedded thermocouple histories with full-history normalized root-mean-square error (NRMSE) below 5%, showing stronger cycle-resolved agreement for peak temperatures than post-peak cooling rates. Comparisons of model configurations showed that enhanced effective liquid conductivity improved peak-temperature agreement, while selected optical and PCE input variations quantified their first-order effects on absorbed power and reinforcement content. The framework provides spatially and temporally resolved thermal histories as inputs for future phase-evolution and microstructure simulations of DED-fabricated MMCs.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"130 ","pages":"Article 105407"},"PeriodicalIF":11.3,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149364250","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}