Additive manufacturing最新文献_第4页

Multiphysics modeling of nitrogen transport and composition evolution during PBF-LB/M of nitrogen-containing austenitic stainless steel 含氮奥氏体不锈钢PBF-LB/M过程中氮输运及组分演化的多物理场建模

IF 11.1 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2026-02-25 Epub Date: 2026-02-02 DOI: 10.1016/j.addma.2026.105109

Tao Zhu , Lai Wei , Chao Wei , Qiang Gong , Tian Huang , Hongkai Jin , Mao Peng , Changqiu Chen , Jiaxing Wen , Xianfeng Shen , Shuke Huang

The content and distribution of nitrogen (N) are critical determinants of the mechanical properties, corrosion resistance, and hydrogen embrittlement resistance of austenitic stainless steels. However, a limited understanding of gas-liquid-solid N transport and compositional evolution during the additive manufacturing of these steels restricts their engineering application. The extreme local temperatures in Laser Powder Bed Fusion (PBF-LB/M) create a dynamic competition between N evaporation loss and absorption from the shielding gas, further complicating this evolution. A key challenge lies in the direct experimental observation of N, a light element, during its dynamic transport within the melt pool and its final distribution in the solidified microstructure. To address this, we developed a multi-physics model integrating "absorption–convection–evaporation–solidification redistribution", which provides a coupled framework describing the evolution of N. Furthermore, via sophisticated Electron Probe Microanalyzer (EPMA) experiments incorporating background noise correction and tracer element (Mn) correlation analysis, we overcame the characterization barriers for N. Results indicate distinct N distribution channels shaped by Marangoni convection and subsequently locked in by rapid solidification, providing direct visual evidence of the melt pool flow's dominant role in shaping the final compositional distribution. Excellent agreement between model and experiment demonstrates that: (1) N transport features spatiotemporally separated competitive processes; (2) Significant non-equilibrium solute trapping (effective partition coefficient k' > 0.9) occurs at the rapid solidification front; and (3) A net N loss is ubiquitous, with high energy input causing the most severe depletion and poorest homogeneity, while low energy input simultaneously mitigates N loss and enhances compositional uniformity. This work elucidates the mechanistic origins of N evolution in PBF-LB/M, establishes a validated predictive framework for process–composition control, and provides a generalizable characterization strategy for tracking light-element transport in metallurgical melt pools.

氮的含量和分布是决定奥氏体不锈钢力学性能、耐蚀性和抗氢脆性的关键因素。然而，在这些钢的增材制造过程中，对气-液-固N输运和成分演变的了解有限，限制了它们的工程应用。在激光粉末床熔合（PBF-LB/M）中，极端的局部温度在N的蒸发损失和保护气体的吸收之间产生了动态竞争，使这一演变进一步复杂化。一个关键的挑战在于直接实验观察轻元素N在熔池中的动态传输过程及其在凝固组织中的最终分布。为了解决这个问题，我们开发了一个集成“吸收-对流-蒸发-凝固再分布”的多物理场模型，该模型提供了一个描述n演变的耦合框架。此外，通过复杂的电子探针微分析仪（EPMA）实验，结合背景噪声校正和示踪元素（Mn）相关分析，我们克服了N的表征障碍。结果表明，不同的N分布通道由马兰戈尼对流形成，随后被快速凝固锁定，这为熔池流动在形成最终成分分布中的主导作用提供了直接的视觉证据。模型与实验结果吻合良好，表明：(1)氮输运具有时空分离的竞争过程；(2)快速凝固前沿存在明显的非平衡溶质俘获（有效分配系数k′>； 0.9）；(3)净氮损失普遍存在，能量输入高，耗损最严重，均一性最差；能量输入低，氮素损失减轻，组分均一性增强。这项工作阐明了PBF-LB/M中N演化的机制起源，建立了一个有效的过程成分控制预测框架，并为跟踪冶金熔池中轻元素输运提供了一种可推广的表征策略。

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引用次数: 0

Data-driven lightweight and robust design of hybrid TPMS structures 数据驱动的混合TPMS结构轻量化和鲁棒性设计

IF 11.1 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2026-02-25 Epub Date: 2026-01-31 DOI: 10.1016/j.addma.2026.105106

H.Y. Ning , W.S. Huang , G.H. Tang

Lightweighting and versatility are key research themes in aerospace, transportation, and robotics. Triply periodic minimal surfaces (TPMS), owing to their unique physical advantages, are considered ideal candidates for achieving these goals. However, existing design approaches fail to effectively explore the complex TPMS design space, especially for hybrid configurations, and exhibit strong sensitivity to the initial topology. This study presents a novel optimization framework for TPMS design. Specifically, the hybrid TPMS structures are employed as internal supports and the mass is minimized under stiffness and strength constraints by regulating topology, periodicity, and wall thickness. To systematically explore the intricate relationship between geometric and physical properties, a two-stage optimization scheme, combining data-driven coarse optimization with gradient-based fine optimization, is proposed. In the first stage, Bayesian optimization is employed to perform a coarse global search and identify a near-optimal topological configuration with fewer evaluations. The solution serves as a high-quality initial guess for the second stage, where a gradient-based method refines local geometric features to achieve optimal structural performance. The optimized structures feature lamellar porous morphologies aligned with the loading direction, enhancing deformation stability and enabling multi-stage energy absorption. Both numerical simulations and mechanical experiments confirm that the present method effectively leverages the intrinsic potential of TPMS architectures. Compared with other advanced designs, this study achieves 5–20% reduction in material consumption while maintaining superior mechanical performance and manufacturability, underscoring its strong promise for engineering applications.

轻量化和多功能性是航空航天、交通运输和机器人领域的关键研究主题。三周期最小表面（TPMS）由于其独特的物理优势，被认为是实现这些目标的理想候选者。然而，现有的设计方法不能有效地探索复杂的TPMS设计空间，特别是对于混合配置，并且对初始拓扑具有很强的敏感性。本研究提出了一种新的TPMS设计优化框架。具体而言，采用混合TPMS结构作为内部支撑，通过调节拓扑结构、周期性和壁厚，在刚度和强度约束下使质量最小化。为了系统地探索几何和物理属性之间的复杂关系，提出了一种将数据驱动的粗优化与基于梯度的精细优化相结合的两阶段优化方案。在第一阶段，使用贝叶斯优化执行粗略的全局搜索，并以较少的评估确定接近最优的拓扑配置。该解决方案为第二阶段提供了高质量的初始猜测，在第二阶段，基于梯度的方法细化局部几何特征以获得最佳结构性能。优化后的结构具有与加载方向一致的层状多孔形态，增强了变形稳定性，实现了多级吸能。数值模拟和力学实验均证实了该方法有效地利用了TPMS结构的内在潜力。与其他先进的设计相比，本研究在保持优异的机械性能和可制造性的同时，减少了5-20%的材料消耗，强调了其在工程应用中的强大前景。

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引用次数: 0

Accelerating laser ray tracing in high fidelity physics simulations of laser melting using squeeze U-net 利用挤压U-net加速激光熔化高保真物理模拟中的激光追踪

IF 11.1 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2026-02-25 Epub Date: 2026-01-14 DOI: 10.1016/j.addma.2026.105087

Robert C. Blake, Saad A. Khairallah

Laser melting is a core component of the ongoing industrial revolution, dubbed Industry 4.0, as lasers facilitate fast and precise melting and fusion in advanced manufacturing. There is a strong need to optimize the laser process using simulations. However, this has proven challenging as high fidelity simulations are needed for predictive modeling and this is currently prohibitively expensive even when run on hundreds of processors on high performance computers. The challenge is capturing complex physics of laser material interaction, fluid dynamics, thermal physics and material phase transformations at various length and time scales. To close this technological gap, we modified a squeeze U-net to accelerate the laser ray tracing component of such high fidelity models by

\sim

4x–40x while preserving the core physics principle of conservation of energy with 97% accuracy. This approach enables the accurate modeling of global laser energy absorption as a function of local surface temperatures and complex surface topologies, which govern the reflection directions and energy losses of laser rays upon interacting with the material surface.

激光熔化是正在进行的工业革命的核心组成部分，被称为工业4.0，因为激光在先进制造中促进了快速精确的熔化和融合。有一个强烈的需要，以优化激光过程中使用模拟。然而，这已经被证明是具有挑战性的，因为预测建模需要高保真度的模拟，而且即使在高性能计算机上运行数百个处理器，目前这也非常昂贵。挑战在于捕捉各种长度和时间尺度下激光材料相互作用、流体动力学、热物理和材料相变的复杂物理。为了缩小这一技术差距，我们改进了挤压U-net，将这种高保真模型的激光跟踪组件加速了4 - 40倍，同时以97%的精度保留了能量守恒的核心物理原理。这种方法能够精确地模拟全局激光能量吸收作为局部表面温度和复杂表面拓扑的函数，这决定了激光与材料表面相互作用时的反射方向和能量损失。

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引用次数: 0

Rapid layerwise process model calibration through a surrogate model for interpass temperature history in laser powder bed fusion 通过替代模型对激光粉末床熔合过程中道间温度历史进行快速分层过程模型标定

IF 11.1 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2026-02-25 Epub Date: 2026-01-19 DOI: 10.1016/j.addma.2026.105091

Shawn Hinnebusch , Praveen S. Vulimiri , Christapher G. Lang , Alaa Olleak , Florian X. Dugast , Albert C. To

Layerwise thermal process simulation is widely used for predicting heat buildup and residual stress in parts built by the laser powder bed fusion (LPBF) process. However, calibration of layerwise process simulation model parameters (such as absorptivity and convection coefficients) using in-process thermal measurements typically requires hundreds of process simulations to reach convergence due to the large model parameter space. To significantly reduce the number of process simulations needed for calibration, this work proposes a surrogate model (SGM) to accurately model the relationship between simulated interpass temperature time history and model parameters needing calibration using simple functions. Specifically, the SGM is constructed by fitting multi-variate polynomials to the temperature histories mapped to a low-dimensional model space through the principal component analysis (PCA), as a function of the process model parameters. Since the SGM is 4–5 orders of magnitude faster than finite element method based process simulations, it can be used to calibrate the model parameters in several minutes. The SGM specifically developed for calibrating three process model parameters requires only ten process simulations to fit its coefficients and is tested to be accurate using 18 simulated temperature histories to fit ten model coefficients, yielding a mean absolute percentage error (MAPE) between 0.12 % and 2.04 % across four test geometries. Applying the fitted surrogate models to calibrate absorptivity, top surface convection coefficient, and part-side surface convection coefficient to match the temperature histories measured by an infrared camera, a MAPE between 2.84 % and 3.46 % is achieved across the four test geometries using the same set of model parameters. Two unseen geometries are tested with the fully calibrated FEM model with errors under 3.7 % MAPE. The proposed SGM approach is demonstrated to be a valuable tool for accurate part-scale thermal prediction by significantly reducing calibration time and computational resources.

分层热过程模拟被广泛用于预测激光粉末床熔合（LPBF）工艺制造的零件的积热和残余应力。然而，由于模型参数空间大，使用过程中热测量的分层过程模拟模型参数（如吸收率和对流系数）的校准通常需要数百个过程模拟才能达到收敛。为了显著减少校准所需的过程模拟次数，本工作提出了一个替代模型（SGM），该模型可以使用简单的函数准确地模拟模拟的通间温度时间历史与需要校准的模型参数之间的关系。具体而言，SGM是通过主成分分析（PCA）将多变量多项式拟合到映射到低维模型空间的温度历史，作为过程模型参数的函数来构建的。由于SGM比基于有限元方法的过程模拟快4-5个数量级，因此可以在几分钟内用于校准模型参数。专门为校准三个过程模型参数而开发的SGM只需要10个过程模拟来拟合其系数，并且使用18个模拟温度历史来拟合10个模型系数进行了准确测试，在四个测试几何形状中产生的平均绝对百分比误差（MAPE）在0.12 %和2.04 %之间。利用拟合的替代模型来校准吸收率、顶面对流系数和部分面对流系数，以匹配红外相机测量的温度历史，使用相同的模型参数，在四种测试几何形状中获得了2.84 %和3.46 %之间的MAPE。用完全校准的有限元模型测试了两个看不见的几何形状，误差在3.7 % MAPE以下。该方法通过显著减少校准时间和计算资源，被证明是一种有价值的精确局部尺度热预测工具。

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引用次数: 0

Microstructure refinement in near-α/Ti2AlNb gradient transition zone by laser deposition-hot deformation hybrid manufacturing 激光沉积-热变形复合制造近α/Ti2AlNb梯度过渡区的显微组织细化

IF 11.1 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2026-02-25 Epub Date: 2026-01-31 DOI: 10.1016/j.addma.2026.105103

Na Liu , Yuli Liu , Zhanglong Zhao , Xiaohui Zha , Wenxuan Zhu , Chenpeng Tong , Haiou Yang , Wei Wang , Heng Li

Gradient titanium alloys, formed by joining dissimilar alloys, integrate superior properties from both ends, yielding enhanced service performance compared to individual alloys. The intrinsic nature of additive manufacturing demonstrates advances in fabricating gradient titanium alloys by smoothing the gradient transition zone (GTZ) in between, thereby avoiding the hard interfaces typical of traditional joining methods. However, additive-manufactured GTZs inevitably exhibit coarse grains that limit their mechanical properties. In this study, the superior microstructure refinement of a near-α/Ti₂AlNb GTZ is achieved through a hybrid manufacturing approach that combines laser deposition with subsequent hot deformation. Results demonstrate that continuous dynamic recrystallization (CDRX) dominates microstructure refinement over discontinuous dynamic recrystallization (DDRX) across all deformation parameters. The CDRX is governed by its interaction with O phase. Specifically, nano-sized O phase preferentially precipitated to low-angle grain boundaries at low strains, effectively pinning boundary migration and suppressing CDRX. The pinning effect weakens with increasing strain, allowing CDRX to proceed. The grain refinement map is established as the function of strain rate and temperature, which sheds light on the fundamental understanding of microstructure refinement in titanium and gradient titanium alloys via additive-hot deformation hybrid manufacturing.

梯度钛合金由不同的合金连接而成，从两端整合了优越的性能，与单独的合金相比，具有更高的使用性能。增材制造的固有性质表明，通过平滑渐变过渡区（GTZ）来制造梯度钛合金，从而避免了传统连接方法典型的硬界面。然而，增材制造的gtz不可避免地表现出粗糙的晶粒，限制了它们的力学性能。在本研究中，通过结合激光沉积和后续热变形的混合制造方法，实现了近α/Ti2AlNb GTZ的优越微观结构细化。结果表明，在所有变形参数中，连续动态再结晶（CDRX）比不连续动态再结晶（DDRX）对微观组织的细化起主导作用。CDRX受其与O相的相互作用控制。在低应变条件下，纳米O相优先向低角度晶界析出，有效钉住晶界迁移，抑制CDRX。钉钉效应随着应变的增加而减弱，使CDRX得以进行。建立了随应变速率和温度变化的晶粒细化图，揭示了增材-热变形复合制造钛合金和梯度钛合金微观组织细化的基本原理。

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引用次数: 0

Preparation and precision control of alumina-based ceramic core using the SLA-Micromilling hybrid process 采用sla -微铣复合工艺制备氧化铝基陶瓷芯及其精度控制

IF 11.1 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2026-02-25 Epub Date: 2026-01-24 DOI: 10.1016/j.addma.2026.105095

Hongyu Xing , Wenxuan Jiang , Xinfeng Wang , Laixiao Lu , Zhenzhong Zhang , Guangchao Hao , Yanhua Zhao , Bin Zou , Chuanzhen Huang

SLA-3D printing technology offers significant advantages in the fabrication of complex ceramic cores. However, several issues must be addressed immediately, which include dimensional deviations caused by light scattering in ceramic-resin slurries, deformation resulting from anisotropic shrinkage during sintering, and surface quality limitations caused by interlayer step effects. To address these issues, a SLA-Micromilling hybrid manufacturing process for preparing alumina-based ceramic cores is proposed, which consists of three stages: SLA-3D printing of the green body, micro-milling refinement of the green body, and debinding sintering. Firstly, a KH570-H/Al₂O₃ ceramic slurry suitable for SLA-3D printing was designed and prepared, capable of being transformed into SiO₂/Al₂O₃ ceramic. During high-temperature sintering, this slurry forms rod-like mullite phases, which improve mechanical properties through a whisker-toughening mechanism. At a sintering temperature of 1400 ℃, the material exhibits a porosity of 33.7 % and a flexural strength of 28.7 MPa. The shrinkage rates in the x, y, and z directions were 10.4 %, 9.8 %, and 13.7 %, respectively. Secondly, to address dimensional deviations caused by the size sensitivity of SLA-3D printed green bodies and sintering anisotropy, a segmented compensation model was established, reducing the deviation rate in both the printing and sintering stages to approximately 5 %. Micro-milling technology was introduced to enhance machining precision even further. A systematic investigation of the material removal mechanisms during micro-milling of green bodies was conducted, including the effects of resin softening and adhesion, as well as ceramic particle attachment on tool wear. Optimizing cutting parameters (a_p=0.3 mm, n = 1100 r/min, f=75 mm/min) resulted in the blank’s surface roughness Ra of 0.3018 μm. Finally, alumina-based complex core samples fabricated using a composite process of SLA printing, micro-milling, and sintering resulted in a significant reduction of surface roughness from 3.571 μm to 0.3113 μm, with a dimensional standard deviation of 0.0588 mm. And the thermal shock resistance, high-temperature creep resistance, and high-temperature chemical stability of ceramic core samples were evaluated.

SLA-3D打印技术在复杂陶瓷芯的制造方面具有显著的优势。然而，有几个问题必须立即解决，其中包括陶瓷树脂浆料中的光散射引起的尺寸偏差，烧结过程中各向异性收缩引起的变形，以及层间台阶效应引起的表面质量限制。为了解决这些问题，提出了一种用于制备氧化铝基陶瓷芯的sla -微铣削混合制造工艺，该工艺包括三个阶段：坯体的SLA-3D打印、坯体的微铣削细化和脱粘烧结。首先，设计并制备了适合SLA-3D打印的KH570-H/Al2O3陶瓷浆料，并将其转化为SiO2/Al2O3陶瓷；在高温烧结过程中，浆料形成棒状莫来石相，通过晶须增韧机制提高机械性能。在1400℃的烧结温度下，材料的孔隙率为33.7% %，抗弯强度为28.7 MPa。x、y、z方向收缩率分别为10.4 %、9.8 %、13.7 %。其次，针对SLA-3D打印绿体尺寸敏感性和烧结各向异性导致的尺寸偏差，建立了分段补偿模型，将打印和烧结阶段的偏差率降低到约5 %。微铣削技术的引入进一步提高了加工精度。系统研究了绿体微铣削过程中材料的去除机理，包括树脂软化和粘附作用以及陶瓷颗粒附着对刀具磨损的影响。优化切削参数（ap=0.3 mm, n = 1100 r/min, f=75 mm/min）后，毛坯表面粗糙度Ra为0.3018 μm。最后，采用SLA打印、微铣削和烧结复合工艺制备的氧化铝基复合芯样品，表面粗糙度从3.571 μm显著降低到0.3113 μm，尺寸标准偏差为0.0588 mm。并对陶瓷岩心样品的抗热震性、高温蠕变性和高温化学稳定性进行了评价。

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引用次数: 0

Integrating 3D-printed metal and polymer geometries with CMOS microdevices toward MEMS high-resolution lateral force sensing 将3d打印金属和聚合物几何形状与CMOS微器件集成到MEMS高分辨率横向力传感

IF 11.1 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2026-02-25 Epub Date: 2026-01-21 DOI: 10.1016/j.addma.2026.105085

Isha Lodhi , Devin K. Brown , Durga Gajula , B.D. Haile , David R. Myers , Wilbur A. Lam , Azadeh Ansari

Advances in metal 3D-microprinting technologies, such as electrodeposition, have meant that Micro-Electro-Mechanical Systems (MEMS) are no longer limited to soft, non-conductive polymers only. However, challenges such as process compatibility, limited optical resolution (and hence alignment), is why metal micro-additive processes have not been integrated with active CMOS circuitry or microdevices. This work demonstrates methods for integrating high-aspect-ratio (HAR) 3D-printed metal pillars with piezoresistive microdevices to produce compact, high-sensitivity MEMS lateral force sensors. Building on our prior demonstration of the first MEMS device made using traditionally (CMOS) fabricated, functional microdevices with 3D-printed metal, we describe the chip and device level modifications necessary for post-CMOS metal 3D-printing using the aqueous and acidic copper electrodeposition workflow. By using surface height mapping of 2.5D alignment marks patterned adjacent to the sub-micron width piezoresistors, we achieve repeatable print-to-microdevice alignment accuracy better than < ±0.5 μm across chips. The resulting sensors pair N-type, silicon-doped piezoresistors with electrodeposited copper pillars (aspect ratio >70). Electrical measurements confirm device integrity after electrodeposition, while electro-mechanical characterization of the force sensors yield sensitivities up to ΔR/R0 = 0.26% μN⁻¹, and a noise-limited resolution of ±35 nN. The electrodeposited HAR copper pillar sensors exhibit excellent linearity, repeatability, and high resistance to delamination due to the metal-to-metal bonding between the copper pillars and underlying conductive traces. In a second study separate to metal 3D-printing, we boost the MEMS force sensor sensitivity with introduction of stress-concentrating, “open” trenches around the silicon piezoresistors. This approach was tested with two-photon polymerized pillars. The polymer pillar sensors, with open trenches, demonstrate sensitivities up to 0.44% μN⁻¹, and a corresponding higher force resolution of ±20 nN. These sensors also show excellent repeatability and low hysteresis but delaminate off of the silicon devices near Fx ≈ 6 μN. Given that both sensor types use pillar-based, out-of-plane mechanics, the active on-chip footprint is confined to a few μm², making them well suited for high spatial resolution force mapping and forming dense arrays for biological cell/tissue mechanics.

金属3d微打印技术的进步，如电沉积，意味着微机电系统（MEMS）不再局限于软的、不导电的聚合物。然而，诸如工艺兼容性、有限的光学分辨率（以及校准）等挑战是金属微增材工艺尚未与有源CMOS电路或微器件集成的原因。这项工作展示了将高纵横比（HAR） 3d打印金属柱与压阻式微器件集成在一起的方法，以生产紧凑、高灵敏度的MEMS横向力传感器。在我们之前演示的第一个使用传统（CMOS）制造的MEMS器件的基础上，我们描述了使用水和酸性铜电沉积工作流程进行后CMOS金属3d打印所需的芯片和器件级修改。通过使用与亚微米宽度压敏电阻相邻的2.5D对齐标记的表面高度映射，我们实现了可重复的打印到微器件的对齐精度，其精度优于芯片之间的±0.5 μm。由此产生的传感器将n型掺杂硅的压阻与电沉积铜柱配对（长宽比>；70）。电测量证实了电沉积后器件的完整性，而力传感器的机电特性产生灵敏度高达ΔR/R0 = 0.26% μN−1，噪声限制分辨率为±35 nN。电沉积HAR铜柱传感器由于铜柱和底层导电迹线之间的金属对金属结合，具有良好的线性、可重复性和高抗分层性。在与金属3d打印分离的第二项研究中，我们通过在硅压敏电阻周围引入应力集中的“开放式”沟槽来提高MEMS力传感器的灵敏度。用双光子聚合柱对该方法进行了测试。该聚合物柱传感器的灵敏度可达0.44% μN−1，相应的力分辨率可达±20 nN。这些传感器也具有优异的重复性和低迟滞，但在Fx≈6 μN附近会从硅器件上脱落。考虑到这两种传感器类型都使用基于柱的平面外力学，芯片上的主动足迹被限制在几μm2，这使得它们非常适合用于高空间分辨率的力映射和形成生物细胞/组织力学的密集阵列。

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引用次数: 0

Microstructure evolution and sensitization of additively manufactured duplex stainless steel during aging heat treatments 增材制造双相不锈钢在时效热处理过程中的组织演变与敏化

IF 11.1 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2026-02-25 Epub Date: 2026-01-29 DOI: 10.1016/j.addma.2026.105100

Philipp Kroeker , Felix Theska , David Miskovic , Nima Haghdadi , Sophie Primig

Duplex stainless steels (DSS) combine excellent mechanical and corrosion resistance properties. They are now increasingly fabricated by laser powder bed fusion (LPBF). A significant concern with DSS is sensitization, which is caused by the formation of deleterious precipitates during exposure to elevated temperatures. Yet, this behavior has never been systematically studied in additively manufactured DSS. Here, we investigate how the unique microstructure of LPBF-manufactured DSS affects the sensitization behavior by comparing hot-rolled, as-built, and solution-annealed LPBF specimens subjected to isothermal aging at 825 °C for 30 to 600 mins. Light optical and scanning electron microscopy, along with electron backscatter diffraction, reveal differences in the microstructural evolution, showing initially slower σ and χ precipitation in LPBF samples due to a more coherent ferrite/austenite boundary structure. Nevertheless, double-loop electrochemical potentiokinetic reactivation testing reveals that the sensitized, as-printed LPBF microstructure exhibits a comparatively faster deterioration of its corrosion resistance. This is attributed to the formation of low-Cr containing austenite during aging at 825 °C. Atom probe tomography corroborates this finding and reveals additional Cr-depletion adjacent to intermetallic phases. The annealed LPBF microstructure, by comparison, combines a favorable solute partitioning with more coherent interfaces, which is deemed responsible for an increased sensitization resistance when benchmarked against the as-built and hot-rolled conditions. This demonstrates that LPBF components, when appropriately heat-treated, can offer advantages over conventionally processed DSS for use in demanding environments.

双相不锈钢（DSS）结合了优异的机械和耐腐蚀性能。现在越来越多地采用激光粉末床熔合（LPBF）制造它们。DSS的一个重要问题是敏化，这是由于暴露在高温下形成有害沉淀物引起的。然而，这种行为从未在增材制造的DSS中进行过系统的研究。在这里，我们研究了LPBF制造的DSS的独特微观结构是如何影响敏化行为的，通过比较热轧、成品和溶液退火的LPBF样品，这些LPBF样品在825°C等温时效30至600 min。光学显微镜和扫描电子显微镜以及电子背散射衍射显示，由于铁素体/奥氏体边界结构更加一致，LPBF样品的σ和χ析出最初较慢。然而，双回路电化学电位动力学再激活测试表明，敏化后的印刷LPBF微观结构的耐蚀性下降相对较快。这是由于在825℃时效过程中形成了含低铬的奥氏体。原子探针断层扫描证实了这一发现，并揭示了金属间相附近额外的cr耗尽。相比之下，退火后的LPBF微观结构结合了有利的溶质分配和更相干的界面，当与成品和热轧条件进行基准测试时，这被认为是增加敏化电阻的原因。这表明，经过适当热处理的LPBF组件可以在苛刻的环境中使用，比传统加工的DSS更具优势。

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引用次数: 0

Applying feedback control to additive manufacturing of graded refractive index lenses with continuous-distributions in permittivity 反馈控制在介电常数连续分布渐变折射率透镜增材制造中的应用

IF 11.1 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2026-02-25 Epub Date: 2026-01-30 DOI: 10.1016/j.addma.2026.105089

Sophie Lekas , Ross Drummond , Qianfang Zheng , Patrick S. Grant , Stephen R. Duncan

Graded refractive index (GRIN) lenses focus and direct electromagnetic waves by making use of spatially-varying material properties to achieve compact, low profile devices in a range of technological applications. For microwave applications, GRIN lenses facilitate performance enhancement of key components such as transmitting and receiving horns used in communication devices. However, the fabrication of GRIN lenses with spatially varying permittivity and/or permeability in order to vary the local refractive index is highly challenging. Recently, additive manufacturing has been used to fabricate GRIN lenses with some success, but accurate control of the local refractive index to meet demanding lens designs is difficult. Here, a feedback control system is designed for improved additive manufacturing of GRIN microwave lenses fabricated from a mixture of both polylactic acid (PLA) and an acrylonitrile butadiene styrene/barium titanate (ABS/BaTiO

_{3}

) composite. After each layer is printed, a controller measures the just-printed local permittivity distribution using a split ring resonator and automatically updates the composition of the next-to-print layer to ensure the resulting local material properties match the design, thus accounting for any printing inconsistencies or defects. The defect structure of lenses without and with the controller are examined using X-ray tomography, and lens performance assessed in the 12-18 GHz range. Overall, the controller is shown to deliver higher fidelity and performance GRIN lenses by ameliorating print defects in real-time during printing.

渐变折射率（GRIN）透镜通过利用空间变化的材料特性来聚焦和直接电磁波，从而在一系列技术应用中实现紧凑，低调的设备。对于微波应用，GRIN透镜有助于提高关键组件的性能，例如通信设备中使用的发射和接收喇叭。然而，制造具有空间变化介电常数和/或渗透率以改变局部折射率的GRIN透镜是非常具有挑战性的。近年来，使用增材制造技术制造GRIN透镜取得了一定的成功，但很难精确控制局部折射率以满足苛刻的透镜设计要求。本文设计了一种反馈控制系统，用于改进由聚乳酸（PLA）和丙烯腈-丁二烯-苯乙烯/钛酸钡（ABS/BaTiO3）复合材料制成的GRIN微波透镜的增材制造。在每一层打印完成后，控制器使用分环谐振器测量刚打印的局部介电常数分布，并自动更新下一层打印层的组成，以确保生成的局部材料属性与设计匹配，从而解决任何打印不一致或缺陷。采用x射线断层扫描技术检测了不带控制器和带控制器的透镜的缺陷结构，并在12-18 GHz范围内评估了透镜的性能。总体而言，该控制器通过在打印过程中实时改善打印缺陷，显示出更高的保真度和性能。

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引用次数: 0

Precipitate evolution in laser metal deposed Haynes 282 investigated using a combination of synchrotron scattering experiment and multi-scale modeling 采用同步加速器散射实验和多尺度模拟相结合的方法研究了激光金属沉积Haynes 282中析出物的演化

IF 11.1 1区工程技术 Q1 ENGINEERING, MANUFACTURING

Additive manufacturing

Pub Date : 2026-02-25 Epub Date: 2026-02-03 DOI: 10.1016/j.addma.2026.105093

Martin Fisk , Anders Ericsson , Manon Bonvalet Rolland , Erik Granhed , Johan Hektor , Alexander Dahlström , Jesper Silwer , Ceena Joseph , Petter Persson , Greta Lindwall

The Ni-based superalloy Haynes 282 exhibits rapid

γ^{'}

precipitation kinetics, and experimental studies have shown the formation of in-process precipitates in samples produced using the direct energy deposition additive manufacturing method, laser metal deposition (LMD). Understanding how these precipitates form and influence the final microstructure is essential for predicting and controlling the mechanical properties of processed Haynes 282. In this study, the particle size and volume fraction of

γ^{'}

precipitates formed in LMD samples are simulated using classical nucleation and growth theory (CNGT). To account for the thermal history during manufacturing, the precipitate model is implemented as a multi-scale framework integrated into a finite element software. Calphad thermodynamic and diffusion data descriptions are used as input to the CNGT model to simulate the precipitation kinetics during different heat treatments. The simulated results are compared with experimental data obtained from small- and wide-angle X-ray scattering, as well as from atom probe tomography. The simulations show good agreement with experimental findings, demonstrating that thermodynamic databases can be used to accurately simulate precipitate evolution in LMD-processed Haynes 282 using CNGT.

ni基高温合金Haynes 282表现出快速的γ′析出动力学，实验研究表明，使用直接能量沉积增材制造方法激光金属沉积（LMD）生产的样品中形成了过程中析出物。了解这些析出物是如何形成并影响最终组织的，对于预测和控制加工后Haynes 282的力学性能至关重要。在本研究中，利用经典的成核生长理论（CNGT）模拟了LMD样品中形成的γ′沉淀的粒径和体积分数。为了考虑制造过程中的热历史，沉淀模型被实现为集成到有限元软件中的多尺度框架。采用calphhad热力学和扩散数据描述作为CNGT模型的输入，模拟不同热处理过程中的沉淀动力学。模拟结果与x射线小角和广角散射以及原子探针层析成像的实验数据进行了比较。模拟结果与实验结果吻合较好，表明热力学数据库可以准确地模拟lmd处理的Haynes 282在CNGT下的沉淀演变。

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引用次数: 0