Materials Science and Engineering: A最新文献_第2页

A machine learning framework augmented by generative models for accelerated design of refractory high-entropy alloys with superior strength-ductility synergy 一个由生成模型增强的机器学习框架，用于具有优越强度-延性协同作用的耐火高熵合金的加速设计

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2026-03-01 Epub Date: 2026-02-14 DOI: 10.1016/j.msea.2026.149938

Liang Zhu, Jiakun Wang, Minghang Zhou, Lingti Kong, Jinfu Li

Achieving a balance between strength and ductility at room temperature remains a grand challenge in developing body-centered cubic (BCC) refractory high-entropy alloys (RHEAs). Facing the vast compositional design space, we propose an alloy design framework, GAMP, combining a Generative Adversarial Network (GAN) with machine learning (ML) prediction models to accelerate the screening of potential alloy compositions. Unlike common inverse design or image-based approaches, the GAN in this work functions as a generator within a forward search loop, specifically capturing the latent distribution of existing alloys to propose high-potential new candidates. Among various models, eXtreme Gradient Boosting (XGBoost) was identified as the most accurate for predicting ultimate tensile strength (UTS) and elongation (El) to failure. A designed alloy, Al_9.6Ti_38.0Nb_20.5Hf_16.5V_15.4, was experimentally validated to exhibit a UTS of 1058.1 MPa and an El of 18.5% at room temperature. Interpretability analysis further revealed that shear modulus local mismatch (G_LM) and atomic size difference (δ) are the dominant descriptors for UTS, while enthalpy of mixing (ΔH_mix) is the key indicator for El. Microstructural analysis revealed that the superior strength-ductility synergy resulted from the activation of multiple deformation mechanisms, in which the formation of kink bands is a key factor enabling the excellent room-temperature ductility. This study presents an efficient framework for designing advanced alloys with complex property requirements.

在室温下实现强度和延性的平衡是体心立方（BCC）耐火高熵合金（RHEAs）的一大挑战。面对巨大的成分设计空间，我们提出了一种合金设计框架GAMP，将生成对抗网络（GAN）与机器学习（ML）预测模型相结合，以加速潜在合金成分的筛选。与常见的逆设计或基于图像的方法不同，GAN在这项工作中充当正向搜索循环中的生成器，特别是捕获现有合金的潜在分布，以提出高潜力的新候选材料。在各种模型中，eXtreme Gradient Boosting （XGBoost）被认为是预测极限抗拉强度（UTS）和断裂伸长率（El）最准确的模型。实验验证了所设计的合金Al9.6Ti38.0Nb20.5Hf16.5V15.4在室温下的抗压强度为1058.1 MPa，电潜值为18.5%。可解释性分析进一步表明，剪切模量局部失配（GLM）和原子尺寸差（δ）是UTS的主要描述符，而混合焓（ΔHmix）是El的关键指标。显微组织分析表明，优异的强度-延性协同效应是多种变形机制激活的结果，其中扭结带的形成是导致优异室温延性的关键因素。该研究为设计具有复杂性能要求的先进合金提供了一个有效的框架。

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引用次数: 0

Hot deformation behavior and recrystallization mechanism of a novel Ni-based superalloy GH4780 新型ni基高温合金GH4780的热变形行为及再结晶机理

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2026-03-01 Epub Date: 2026-01-27 DOI: 10.1016/j.msea.2026.149836

Yang Liu , Xingfei Xie , Tianhao Feng , Xing Su , Jinglong Qu , Jinhui Du , Lilong Zhu

Ni-based superalloys serve as critical high-temperature components in advanced aerospace engines, where precise prediction of hot deformation behavior and microstructural evolution is essential for manufacturing process optimization. This study systematically investigates the hot deformation characteristics and dynamic recrystallization (DRX) mechanisms of a novel GH4780 superalloy through thermal compression experiments spanning 1030–1120 °C and strain rates of 0.001–1 s⁻¹. A corrected constitutive model integrating friction, thermal, and strain effects was developed, demonstrating excellent predictability of flow behavior across the tested conditions. Microstructural analysis via electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) reveals that discontinuous dynamic recrystallization (DDRX) dominates the softening process, while twin-induced dynamic recrystallization (TDRX) significantly enhances nucleation at grain boundaries. Continuous dynamic recrystallization (CDRX) functions as a supplementary mechanism active particularly under low-temperature and high-strain-rate conditions. The activation energy (Q) for hot deformation ranges from 427.70 to 476.42 kJ mol⁻¹, with higher values corresponding to enhanced degree of DRX, typically presenting as larger recrystallized areas or grain structures exhibiting both uniform size and homogeneous distribution. These findings provide fundamental insights into the multi-mechanism DRX behavior of GH4780 superalloy, establishing a theoretical basis for optimizing its thermo-mechanical processing parameters.

镍基高温合金是先进航空发动机的关键高温部件，其热变形行为和微观组织演变的精确预测对于制造工艺优化至关重要。本研究系统地研究了一种新型GH4780高温合金的热变形特性和动态再结晶（DRX）机制，通过热压缩实验在1030 ~ 1120°C范围内，应变速率为0.001 ~ 1 s−1。开发了一个整合摩擦、热和应变效应的修正本构模型，证明了在测试条件下流动行为的良好可预测性。通过电子背散射衍射（EBSD）和透射电镜（TEM）的显微组织分析发现，不连续动态再结晶（DDRX）主导了软化过程，而双诱导动态再结晶（TDRX）显著增强了晶界处的形核。连续动态再结晶（CDRX）是一种辅助机制，尤其在低温和高应变速率条件下具有活性。热变形活化能Q在427.70 ~ 476.42 kJ mol−1之间，DRX增强程度越高，再结晶面积越大或晶粒尺寸均匀、分布均匀。研究结果为深入了解GH4780高温合金的多机制DRX行为提供了基础，为优化GH4780高温合金的热机械加工参数奠定了理论基础。

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引用次数: 0

Additive manufacturing of stainless steel with controllable phase compositions: from ferrite, duplex phase to austenite stainless steel 可控相组成不锈钢的增材制造：从铁素体、双相到奥氏体不锈钢

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2026-03-01 Epub Date: 2026-02-05 DOI: 10.1016/j.msea.2026.149772

Yujin Nie , Liuwei Zheng , Fei Yang , Lixin Meng , Quanxin Shi , Jinyao Ma , Wei Liang

The microstructure is typically a relatively fixed phase with limited tunability when fabricated by Laser powder bed fusion (LPBF) using fixed-composition powders. This limitation hinders the flexible preparation of diverse microstructures. To achieve continuous control of microstructures from pure ferrite to pure austenite and overcome the challenges in fabricating duplex stainless steels, this study innovatively proposes a novel strategy based on in-situ laser alloying of heterogeneous powders. By adjusting the mixing ratio of commonly available 430 and 316L powders, stainless steel with controllable ferrite/austenite phase ratios was successfully fabricated, enabling the direct production of duplex stainless steels. The results demonstrate that under different powder ratios, the as-built alloys consist solely of ferrite and/or austenite due to the extremely rapid cooling rate, which suppresses elemental diffusion and prevents nucleation and growth for secondary phases. With increasing mass percentage of 316L powder, the volume fraction of austenite gradually increased from 0% to 100%, while the coexistence of dual phases significantly refined grain size. The as-built alloys exhibit higher ultimate tensile strength and excellent elongation, all demonstrating superior comprehensive mechanical properties compared to additively manufactured stainless steels of the same type. Ferrite achieves remarkable strengthening through high-density dislocations, whereas austenite enhances plasticity synergistically via the formation of stacking faults, nano-twins, dislocations, and their cellular structures. The TRIP effect occurring during deformation not only hindered dislocation motion but also effectively promoted stress redistribution, further optimizing the strength-ductility balance. This research provides an innovative solution for the integrated "process-microstructure-properties" design of additively manufactured stainless steels.

使用固定成分的粉末进行激光粉末床熔合（LPBF）制备时，其微观结构通常是相对固定的相，可调性有限。这一限制阻碍了不同微结构的柔性制备。为了实现从纯铁素体到纯奥氏体的连续组织控制，克服双相不锈钢制造中的挑战，本研究创新性地提出了一种基于非均相粉末原位激光合金化的新策略。通过调整常用的430和316L粉末的混合比例，成功制备了铁素体/奥氏体相比可控的不锈钢，实现了双相不锈钢的直接生产。结果表明：在不同的粉末配比下，由于极快的冷却速度，形成的合金仅由铁素体和/或奥氏体组成，这抑制了元素的扩散，阻止了二次相的形核和生长。随着316L粉末质量分数的增加，奥氏体的体积分数从0%逐渐增加到100%，同时双相的共存使晶粒尺寸明显细化。与同类型的增材制造不锈钢相比，成品合金具有更高的极限抗拉强度和优异的伸长率，所有这些都显示出优越的综合机械性能。铁素体通过高密度位错实现显著强化，而奥氏体通过层错、纳米孪晶、位错及其细胞结构的形成协同增强塑性。变形过程中发生的TRIP效应不仅阻碍了位错的运动，而且有效地促进了应力的重新分布，进一步优化了强度-塑性平衡。本研究为增材制造不锈钢的“工艺-显微组织-性能”集成设计提供了一种创新的解决方案。

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引用次数: 0

In-situ fabrication of NiTiTa alloys by laser-directed energy deposition: Strength-toughness synergy mechanisms 激光定向能沉积原位制备NiTiTa合金：强度-韧性协同机制

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2026-03-01 Epub Date: 2026-01-29 DOI: 10.1016/j.msea.2026.149860

Yan Wu, Guangyi Ma, Xinhui Li, Tengda Di, Bin Wu, Yunlong Li, Fangyong Niu, Dongjiang Wu, Danlei Zhao

While operating temperature demands for aerospace actuators continue to rise, tantalum (Ta) addition has emerged as a promising approach to developing high-temperature NiTi shape memory alloys (SMAs). However, the high melting point of Ta causes severe elemental segregation in NiTiTa alloys with conventional fabrication methods due to insufficient cooling rates. In this study, NiTiTa SMAs were successfully fabricated via in-situ alloying using laser-directed energy deposition (L-DED), which leverages its high cooling rate to achieve a homogeneous microstructure. This study systematically investigates the influence of Ta content (0–9 at.%) on the microstructure and properties of NiTi alloys. The as-deposited NiTiTa alloys exhibited a eutectic microstructure composed of a B19′ martensitic matrix, (Ti, Ta)₂Ni precipitates, and β-Ta phases. The incorporation of Ta resulted in substantial grain refinement, with a reduction of up to 86 %, and increased the ultimate tensile strength by 27 % via solid solution strengthening, achieving a strength-toughness synergy. Futheremore, Ta addition systematically elevated the phase transformation temperatures, and the martensite start temperature (M_s) reached approximately 80 °C in the high Ta content alloy, primarily due to the reduction in matrix Ni content, along with the martensite stabilizing effects of Ta solute atoms and high-density dislocations. This work demonstrates that L-DED is an effective technique for in-situ fabricating homogeneous NiTiTa SMAs with refined microstructures, enhanced strength, and tunable transformation temperatures, providing new insights for developing high-performance NiTi-based SMAs.

随着航空航天执行器对工作温度的要求不断提高，添加钽（Ta）已成为开发高温NiTi形状记忆合金（sma）的一种有前途的方法。然而，高熔点的Ta，导致严重的元素偏析在NiTiTa合金与传统的制造方法，由于不够的冷却速度。在本研究中，利用激光定向能沉积（L-DED）技术，通过原位合金化成功制备了NiTiTa sma，该技术利用其高冷却速率实现了均匀的微观结构。本研究系统地考察了Ta含量（0 ~ 9）的影响。%)对NiTi合金的组织和性能的影响。沉积态NiTiTa合金为由B19′马氏体基体、（Ti, Ta）2Ni相和β-Ta相组成的共晶组织。Ta的加入导致了大量的晶粒细化，减少了高达86%，并通过固溶强化提高了27%的极限抗拉强度，实现了强度-韧性协同。此外，Ta的加入系统地提高了相变温度，在高Ta含量合金中，马氏体起始温度（Ms）达到约80℃，这主要是由于基体Ni含量的降低，以及Ta溶质原子和高密度位错的马氏体稳定作用。这项工作表明，L-DED是一种有效的原位制备均匀niti sma的技术，具有精细的微观结构、增强的强度和可调的转变温度，为开发高性能niti基sma提供了新的见解。

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引用次数: 0

Anisotropic high-temperature embrittlement of laser powder bed fused Al-Fe-Cr alloy containing Si element 激光粉末床熔合含硅Al-Fe-Cr合金的各向异性高温脆化

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2026-03-01 Epub Date: 2026-02-02 DOI: 10.1016/j.msea.2026.149875

Yifan Xu , Dasom Kim , Koki Minamihama , Junji Umeda , Yuhki Tsukada , Naoki Takata

This study focused on an Al-Fe-Cr alloy system with a certain amount of Si (a major impurity in Al alloys) as a model for high-temperature alloys with an industrially produced composition suitable for laser-beam powder bed fusion (PBF-LB) processing. The phase equilibria and solidification sequence in the experimental alloy composition of Al-2.5Fe-2Cr-0.5Si (mass%) were analyzed via thermodynamic calculations. The gas-atomized alloy powder exhibited excellent processability in the PBF-LB process, resulting in the manufacture of fully dense alloy specimens with relative densities exceeding 99%. The PBF-LB-fabricated Al-Fe-Cr-Si alloy exhibited a melt-pool structure formed through repeated local melting and rapid solidification during scanning laser irradiation. Several grains containing high-density low-angle boundaries (sub-boundaries) were elongated along the building direction (BD) in the α-Al matrix with a crystallographic texture of <110>//BD. The relatively coarsened Al₁₁Cr₂ phases were localized around the melt pool boundaries, whereas numerous nanosized particles of the Al₆Fe metastable phase containing Si and Cr were dispersed within the melt pool interior. Consequently, the strength of the Al-Fe-Cr-Si alloy specimen was considerably higher than that of the Al-Fe binary alloys. However, the Al-Fe-Cr-Si alloy specimen exhibited significant ductility loss only in the direction perpendicular to the BD upon elevating the test temperature to 300 °C. The high-temperature embrittlement may be attributed to preferential fracture at many precipitates of the Si-rich intermetallic phase (presumably brittle) formed at the boundaries of the α-Al grains elongated along the BD. These results provide new insights into the design of alloy composition, including impurity elements, for controlling the high-temperature mechanical performance of Al-Fe multi-elemental alloys suitable for PBF-LB processing.

本研究的重点是Al- fe - cr合金体系，其中含有一定量的Si（铝合金中的主要杂质），作为高温合金的模型，其工业生产成分适合激光粉末床熔合（PBF-LB）加工。通过热力学计算分析了Al-2.5Fe-2Cr-0.5Si（质量%）合金组成中的相平衡和凝固顺序。气雾化合金粉末在PBF-LB工艺中表现出良好的可加工性，制备出相对密度超过99%的全致密合金试样。pbf - lb制备的Al-Fe-Cr-Si合金在扫描激光照射过程中表现出反复局部熔化和快速凝固形成的熔池结构。α-Al基体中含有高密度低角度晶界（亚晶界）的晶粒沿构建方向（BD）拉长，晶体织构为<；110>//BD。相对粗化的Al11Cr2相集中在熔池边界附近，而含有Si和Cr的Al6Fe亚稳相则分散在熔池内部。因此，Al-Fe- cr - si合金试样的强度明显高于Al-Fe二元合金试样。然而，当试验温度升高至300℃时，Al-Fe-Cr-Si合金试样仅在与BD垂直的方向上表现出明显的塑性损失。高温脆性的形成可能是由于α-Al晶粒沿BD伸长边界形成的富si金属间相（可能为脆性）的许多析出相优先断裂所致。这些结果为设计含杂质元素的合金成分以控制适合PBF-LB加工的Al-Fe多元素合金的高温力学性能提供了新的思路。

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引用次数: 0

Toughening and deformation mechanisms of dual heterogeneous SiCp/2024Al composites 双非均相SiCp/2024Al复合材料的增韧变形机理

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2026-03-01 Epub Date: 2026-01-27 DOI: 10.1016/j.msea.2026.149840

Kan Liu , Yunpeng Cai , Aoke Jiang , Lichaoran Guan , Yiwei Dong , Ruian Wang , Yishi Su , Qiubao Ouyang , Di Zhang

The deformation mechanism of heterogeneous Al matrix composites is yet unclear. Here, dual heterogeneous SiCp/2024Al composites integrating bimodal dispersoids within heterogeneous nano-laminated matrix were fabricated via powder metallurgy. Superior mechanical properties of 97.7 GPa, 713.5 MPa and 6.5 % respectively in modulus, tensile strength and elongation are obtained, with ductility elevated by 81 % by sacrificing only 3 % strength, leading to a toughness of 41.5 MJ/m³ that is 77 % higher than uniform ultrafine-grained (UFG) counterparts. Dislocation strengthening is the primary strengthening mechanism due to the enhanced dislocation storage. Deformation rate-controlled mechanisms were studied by strain rate jumping tests. Grain boundary-dislocation interaction is identified as the deformation mechanism of UFG counterparts, due to the increased dislocation absorption into grain boundaries. Dual heterogeneous composites exhibit lower strain rate sensitivity and higher activation volumes, whose deformation is mediated by forest dislocation cutting despite having only 594 nm in average matrix grain size. The transition in deformation mechanisms originates from hetero-interface induced extra geometrically necessary dislocation multiplication and intersection, facilitating an improved strain hardening. This work may provide insight into architecture induced toughening for metal matrix composites.

非均相铝基复合材料的变形机理尚不清楚。采用粉末冶金法制备了在非均相纳米层状基体中集成双峰分散体的双非均相SiCp/2024Al复合材料。模量、抗拉强度和伸长率分别达到97.7 GPa、713.5 MPa和6.5%的优异力学性能，仅牺牲3%的强度，塑性提高81%，韧性达到41.5 MJ/m3，比均匀超细晶（UFG）材料高77%。由于位错储存的增强，位错强化是主要的强化机制。通过应变速率跳变试验研究了变形速率控制机理。由于位错对晶界的吸收增加，确定了晶界-位错相互作用是UFG对应物的变形机制。双非均相复合材料表现出较低的应变率敏感性和较高的激活体积，其变形是由森林位错切削介导的，尽管其平均基体晶粒尺寸只有594 nm。变形机制的转变源于异质界面引起的额外几何必要的位错倍增和交集，促进了应变硬化的改善。这项工作可能为金属基复合材料的结构诱导增韧提供新的见解。

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引用次数: 0

The effect of standard heat treatments and process conditions on the fatigue performance of wire arc additively manufactured Ti-6Al-4V 研究了标准热处理工艺条件对电弧增材制造Ti-6Al-4V丝疲劳性能的影响

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2026-03-01 Epub Date: 2026-02-03 DOI: 10.1016/j.msea.2026.149833

Jackson Leigh Smith , Alexander Medvedev , Edward Lui , Jiayu Ye , Philip Pille , Stephen Sun , Michael Bermingham , Daniel Fisher , Jisheng Ma , Martin Leary , Qianchu Liu , Milan Brandt

Wire arc additive manufacturing (WAAM) offers a cost-effective route for producing large, customised Ti-6Al-4V airframe components, yet the influence of heat treatments and process conditions on fatigue life remains unclear. This study examines how fatigue performance is shaped by standard additive manufacturing heat treatments, including stress relieving (SR), solution treating and aging (STA), hot isostatic pressing (HIP) and annealing, and key process parameters, including nozzle to workpiece distance and shielding atmosphere. STA refined the microstructure and increased strength but produced little improvement in fatigue life, while SR had negligible effects due to already low residual stresses in the as-machined state. In contrast, annealed specimens built with a more optimal nozzle to workpiece distance showed improved fatigue life despite lower yield strength, driven by high relative density (>99.99 percent) and greater ductility. HIP produced full densification and the best fatigue performance. Poor shielding reduced relative density and degraded fatigue resistance, despite strengthening from diffused oxygen. Fractography revealed that fatigue cracks initiated at sharp notches around clustered gas pores, where high stress concentrations accelerated crack coalescence and ligament rupture. Overall, the results demonstrate that clustered porosity, not microstructural refinement or strength alone, governs fatigue life in WAAM Ti-6Al-4V, highlighting the need to control pore nucleation and growth for reliable aerospace use.

电弧增材制造（WAAM）为生产大型定制Ti-6Al-4V机身部件提供了一种经济高效的途径，但热处理和工艺条件对疲劳寿命的影响尚不清楚。本研究考察了标准增材制造热处理（包括应力消除（SR）、固溶处理和时效（STA）、热等静压（HIP）和退火）以及关键工艺参数（包括喷嘴到工件的距离和屏蔽气氛）如何塑造疲劳性能。STA细化了微观组织，提高了强度，但对疲劳寿命的改善很小，而SR的影响可以忽略不计，因为在加工状态下残余应力已经很低。相比之下，在较高的相对密度（> 99.99%）和更大的延展性的驱动下，使用更优化的喷嘴到工件距离构建的退火试样显示出更高的疲劳寿命，尽管屈服强度较低。HIP合金致密化程度高，疲劳性能好。尽管扩散氧增强了涂层的强度，但屏蔽效果差会降低涂层的相对密度和抗疲劳性能。断口分析表明，疲劳裂纹起源于聚集的气孔周围的尖锐缺口，在那里，高应力集中加速了裂纹的合并和韧带断裂。总体而言，研究结果表明，集群孔隙率，而不仅仅是微观结构的细化或强度，决定了WAAM Ti-6Al-4V的疲劳寿命，这突出了控制孔隙成核和生长的必要性，以实现可靠的航空航天应用。

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引用次数: 0

Microstructure and mechanical properties of 2219 aluminum alloy fabricated by dual ultrasonic impact treatment-assisted wire-arc directed energy deposition 双超声冲击处理辅助线弧定向能沉积制备2219铝合金的组织与力学性能

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2026-03-01 Epub Date: 2026-02-03 DOI: 10.1016/j.msea.2026.149885

Dongqing Yang , Jun Feng , Zehui Qin , Gaige Chang , Lei Wang , Yong Huang , Xiaopeng Li

To address issues such as microstructural inhomogeneity, coarse grains, and porosity defects in 2219 aluminum alloy fabricated by wire-arc directed energy deposition (WA-DED), this study introduces dual ultrasonic impact treatment (D-UIT) into the WA-DED process. By establishing a D-UIT-assisted WA-DED system, the effects of D-UIT on the microstructure and mechanical properties of single-bead multi-layer deposited samples were investigated. Results indicate that D-UIT notably refines the grain structure, reducing the average grain size to a range of 62.08–71.69 μm. It eliminates coarse columnar crystals and strong texture, leading to a significant improvement in microstructural homogeneity, with a 65% reduction in the maximum pole density value. Meanwhile, the average pore volume and porosity of the D-UIT-treated WA-DED samples decreased by 93.3% and 91.8%, respectively. D-UIT also increased the microhardness by 24%, and the tensile strength improved by 15.2% in the horizontal direction and 9.0% in the vertical direction. These enhancements are primarily attributed to the combined effects of grain refinement strengthening, defect control, and texture weakening induced by D-UIT. Therefore, D-UIT-assisted WA-DED provides a novel approach for producing high-performance metal components and holds broad application potential.

针对线弧定向能沉积（WA-DED）制备2219铝合金过程中存在的组织不均匀、晶粒粗大、气孔缺陷等问题，将双超声冲击处理（D-UIT）引入到WA-DED工艺中。通过建立D-UIT辅助的WA-DED系统，研究了D-UIT对单珠多层沉积样品微观结构和力学性能的影响。结果表明：D-UIT显著细化了晶粒组织，使晶粒平均尺寸减小至62.08 ~ 71.69 μm；它消除了粗柱状晶体和强烈的织构，导致微观组织均匀性的显著改善，最大极密度值降低了65%。同时，经d - unit处理的WA-DED样品的平均孔隙体积和孔隙率分别降低了93.3%和91.8%。D-UIT的显微硬度提高了24%，抗拉强度在水平方向提高了15.2%，在垂直方向提高了9.0%。这些增强主要归因于D-UIT诱导的晶粒细化强化、缺陷控制和织构弱化的综合作用。因此，d - unit辅助的WA-DED为生产高性能金属部件提供了一种新的方法，具有广阔的应用潜力。

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引用次数: 0

Enhanced strength and ductility in aluminum alloys produced by laser powder bed fusion: Tunable nano-precipitates effect via copper addition 激光粉末床熔合提高铝合金的强度和延展性：通过添加铜可调节纳米沉淀效应

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2026-03-01 Epub Date: 2026-02-01 DOI: 10.1016/j.msea.2026.149870

Hai Hu , Bin Yin , Lei Qin , Fei Xu , Huan Yang , Cheng Deng , Shengfeng Zhou

To enhance the limited strength of as-printed AlMgErZrSc alloys, cost-effective Cu was introduced into the AlMgErZrSc system via laser powder bed fusion (LPBF). A systematic investigation was conducted to study the effect of Cu content (1, 3, 5, 7 wt%) on microstructure and mechanical properties. The results demonstrate that increasing Cu content from 0 to 7 wt% can enlarge the width of the fine equiaxed zone (FEZ) at the molten pool boundaries from 1.5 ± 0.17 μm to 13.3 ± 0.93 μm-a ninefold enhancement. This microstructural evolution is driven by Cu-induced constitutional supercooling and heterogeneous nucleation of Al₃(Sc,Zr) precipitates, which synergistically facilitate the formation of fine equiaxed grains. At Cu concentrations ≥3 wt%, the eutectic reaction is activated, stabilizing the precipitation of S-Al₂CuMg. This process consumes Mg, suppressing β-Mg₂Si formation and creating competitive precipitation dynamics. The nanoscale S-Al₂CuMg and β-Mg₂Si distributed at the grain boundaries of α-Al matrix generate a pinning effect, effectively impeding dislocation movement and strengthening the α-Al matrix. However, adding excessive Cu (7 wt%) can lead to high dislocation density (∼1.41 × 10¹⁵ m⁻²) and coarse secondary S-Al₂CuMg, thereby inducing stress concentration and a reduction in ductility. Therefore, the AlMgErZrSc-5Cu alloy exhibits an enhanced ultimate tensile strength of 534 ± 8 MPa and elongation of 8.6 ± 0.9%. The Cu-induced strengthening mechanisms include: (i) solid-solution strengthening of Cu, (ii) grain-boundary strengthening of α-Al, (iii) dislocation strengthening, and (iv) precipitation strengthening from L1₂-Al₃(Sc,Zr)/S-Al₂CuMg/β-Mg₂Si nano-phases.

为了提高AlMgErZrSc合金的有限强度，通过激光粉末床熔合（LPBF）将具有成本效益的Cu引入AlMgErZrSc体系。系统研究了Cu含量（1、3、5、7 wt%）对合金显微组织和力学性能的影响。结果表明，当Cu含量从0 wt%增加到7 wt%时，熔池边界的细等轴区宽度从1.5±0.17 μm增加到13.3±0.93 μm，增加了9倍；cu诱导的晶型过冷和Al3（Sc,Zr）析出相的非均匀形核共同促进了细小等轴晶的形成。当Cu浓度≥3wt %时，共晶反应被激活，S-Al2CuMg的沉淀稳定。这一过程消耗Mg，抑制β-Mg2Si的形成并产生竞争性沉淀动力学。分布在α-Al基体晶界处的纳米级S-Al2CuMg和β-Mg2Si产生钉钉效应，有效阻碍位错运动，强化α-Al基体。然而，添加过量的Cu （7wt %）会导致高位错密度（~ 1.41 × 1015 m−2）和粗次生S-Al2CuMg，从而引起应力集中和塑性降低。结果表明，AlMgErZrSc-5Cu合金的抗拉强度为534±8 MPa，伸长率为8.6±0.9%。Cu诱导的强化机制包括：(i) Cu的固溶强化，(ii) α-Al的晶界强化，（iii）位错强化，以及（iv） L12-Al3(Sc,Zr)/S-Al2CuMg/β-Mg2Si纳米相的析出强化。

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引用次数: 0

Subsurface microstructure versus surface topography: Impact on the fatigue strength of stress-relieved Laser Powder Bed Fusion (L-PBF) 316L parts 亚表面微观结构与表面形貌：对应力消除激光粉末床熔化（L-PBF） 316L零件疲劳强度的影响

IF 7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2026-03-01 Epub Date: 2026-01-29 DOI: 10.1016/j.msea.2026.149826

Marion Auffray , Linamaria Gallegos Mayorga , Franck Morel , Etienne Pessard , Thierry Baffie

The Laser Powder Bed Fusion (L-PBF) process allows to manufacture parts with both a complex geometry and a high mechanical performance. The as-built and net-shape L-PBF 316L stainless steel parts - i.e. without any heat nor surface treatment, have tensile residual stresses, subsurface pores, a rough surface and a contour-core microstructure that synergistically lead to a low fatigue strength. Residual stresses can be relieved with a heat-treatment to enhance the fatigue properties, but the best performance is obtained after machining and polishing. The differences between the polished and the heat-treated net-shape conditions lie in the subsurface microstructure, the surface topography, and the population of subsurface pores. This study aims to quantify the impact of each of these subsurface parameters on the fatigue behaviour. To do so, the subsurface microstructure of the net-shape condition is characterised. Then, uni-axial fatigue tests are carried out on stress-relieved specimens with the following surface conditions: net-shape, partially polished, and “machined and polished”. The Kitagawa-Takahashi representation shows that for defects smaller than

200 μ m

, the subsurface microstructure is the most influential parameter on the fatigue strength. Conversely, the surface topography has a limited influence. After examining the microstructure surrounding killer defects of both net-shape and polished specimens, the grain size under the surface of all surface conditions is considered in the Kitagawa-Takahashi diagram relatively to the killer defect size: this allows to align the various batches’ results.

激光粉末床融合（L-PBF）工艺允许制造具有复杂几何形状和高机械性能的零件。成品和净形的L-PBF 316L不锈钢部件-即未经任何热处理或表面处理，具有拉伸残余应力，表面下孔隙，粗糙表面和轮廓芯微观结构，这些协同作用导致低疲劳强度。热处理可以消除残余应力，提高材料的疲劳性能，但加工和抛光后的材料性能最好。抛光和热处理净形条件的区别在于地下微观结构、表面形貌和地下孔隙的数量。本研究旨在量化这些地下参数对疲劳行为的影响。为此，对净形条件下的地下微观结构进行了表征。然后，对去应力试样进行净形、部分抛光和“加工抛光”表面条件下的单轴疲劳试验。Kitagawa-Takahashi表示表明，对于小于200μm的缺陷，亚表面组织是影响疲劳强度最大的参数。相反，表面形貌的影响有限。在检查了净形和抛光试样的杀伤缺陷周围的微观结构后，在Kitagawa-Takahashi图中考虑了所有表面条件下的晶粒尺寸相对于杀伤缺陷尺寸：这允许对不同批次的结果进行对齐。

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引用次数: 0