Materials Science and Engineering: A最新文献

Investigating the effects of extrusion temperature and speed on the mechanical properties of high-strength Al-Mg-Si alloys using machine learning methods 采用机器学习方法研究了挤压温度和挤压速度对高强度Al-Mg-Si合金力学性能的影响

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

Materials Science and Engineering: A

Pub Date : 2026-02-01 DOI: 10.1016/j.msea.2026.149858

Jun Li , Lingying Ye , Yu Wang , Yuhui Wang , Guotong Zou , Tao Duan , Jianguo Tang

Traditional approaches to designing process parameters for new alloys often rely on inefficient trial-and-error methods. In this study, elemental physicochemical parameters were integrated with feature selection to develop a machine learning prediction model with robust predictive capability. Through Pareto analysis, the optimal extrusion parameters for high-strength Al-Mg-Si alloys were determined as an extrusion ratio (EXR) of 40, temperature (EXT) of 540 °C, and speed (EXS) of 1.1 mm/s. Under these conditions, the ultimate tensile strength (UTS), yield strength (YS), and elongation (EL) were 402.4 MPa, 385.5 MPa, and 10.3 %, respectively. Additionally, significant nonlinear interactions between process parameters and mechanical properties were revealed through Shapley additive explanations (SHAP) analysis. Through electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM), the strength-ductility mechanism was attributed to the competing effects of grain boundaries, dislocations, textures, and precipitates. This data-driven strategy provides a robust methodology for optimizing and designing alloy processing parameters.

设计新合金工艺参数的传统方法往往依赖于低效的试错方法。本研究将元素理化参数与特征选择相结合，建立了具有鲁棒预测能力的机器学习预测模型。通过Pareto分析，确定了高强度Al-Mg-Si合金的最佳挤压参数为挤压比（EXR）为40，温度（EXT）为540℃，速度（EXS）为1.1 mm/s。在此条件下，拉伸强度（UTS）、屈服强度（YS）和伸长率（EL）分别为402.4 MPa、385.5 MPa和10.3%。此外，通过Shapley加性解释（SHAP）分析，发现工艺参数与力学性能之间存在显著的非线性相互作用。通过电子背散射衍射（EBSD）和透射电子显微镜（TEM）分析，分析了晶界、位错、织构和析出相的竞争作用对强度-延性的影响。这种数据驱动的策略为优化和设计合金加工参数提供了一个强大的方法。

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引用次数: 0

Composition design and optimization of a Ni-Co based wrought superalloy for 750 °C service 一种适用于750°C的镍钴基变形高温合金的成分设计与优化

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

Materials Science and Engineering: A

Pub Date : 2026-02-01 DOI: 10.1016/j.msea.2026.149829

Yuheng Zhang , Shuaicheng Zhu , Yihuan Cao , Wei Yong , Hongtao Zhang , Huadong Fu , Jianxin Xie

The development of next-generation aero-engines necessitates wrought superalloys with operational stability at ≥750 °C while maintaining an optimal balance between elevated tensile strength, retained ductility, and hot workability compatible with industrial manufacturing requirements. Accordingly, a Ni-Co based superalloy with the composition of Ni-22Co-12.5Cr-2.9Al-5.5Ti-1.6W-2.4Mo-0.02C-0.02B-0.03Zr (wt%) was designed via integrated high-throughput thermodynamic calculations and machine learning. Post solution treatment and aging, the experimental alloy achieves a γ′ phase volume fraction of ∼45 % with an average radius of ∼92 nm, demonstrating excellent microstructural stability characterized by absent Topologically Close-Packed (TCP) phase formation during 750 °C/500h thermal exposure, alongside a favorable thermal processing window spanning approximately 180 °C. Notably, 1 wt% Ta addition simultaneously enhances yield strength and elongation without inducing deleterious TCP phases, while effectively retarding γ′ coarsening kinetics. Conversely, 1 wt% Nb incorporation improves strength at the expense of severe ductility reduction and accelerated coarsening. The optimized Ta-modified alloy (Ni-Co-1Ta) demonstrates a 15.2 % higher 750 °C yield strength with concurrent ductility improvement relative to TMW-4M3, establishing it as a promising candidate material for next-generation turbine disk applications requiring 750 °C service capability.

下一代航空发动机的发展需要在≥750°C下工作稳定的变形高温合金，同时保持高抗拉强度、保留延展性和与工业制造要求兼容的热加工性之间的最佳平衡。据此，通过综合高通量热力学计算和机器学习，设计了Ni-22Co-12.5Cr-2.9Al-5.5Ti-1.6W-2.4Mo-0.02C-0.02B-0.03Zr （wt%）的Ni-Co基高温合金。固溶处理和时效后，实验合金的γ′相体积分数为~ 45%，平均半径为~ 92 nm，在750°C/500h的热暴露过程中没有形成拓扑紧密堆积（TCP）相，并具有约180°C的有利热处理窗口，表现出优异的微观结构稳定性。值得注意的是，添加1 wt%的Ta同时提高了屈服强度和伸长率，而不会产生有害的TCP相，同时有效地延缓了γ′粗化动力学。相反，掺入1wt %的铌可以提高强度，但代价是严重的塑性降低和加速粗化。与TMW-4M3相比，经过优化的ta改性合金（Ni-Co-1Ta）的750°C屈服强度提高了15.2%，同时延展性也有所改善，这使其成为需要750°C服务能力的下一代涡轮盘应用的有希望的候选材料。

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引用次数: 0

Additive manufacturing of TiZrNb lightweight refractory medium-entropy alloy with excellent mechanical properties 力学性能优异的TiZrNb轻质耐火中熵合金的增材制造

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

Materials Science and Engineering: A

Pub Date : 2026-02-01 DOI: 10.1016/j.msea.2026.149837

Ba Chen , Abdukadir Amar , Peter K. Liaw , Yiping Lu

A key limitation of TiZrNb-based lightweight refractory medium-entropy alloys (LRMEAs) is their low yield strength, despite their low density and status as the most widely studied system in the family of lightweight refractory alloys. Additive manufacturing (AM) is a technique that builds objects layer by layer, enabling the production of complex metal components with a high degree of design flexibility. In this study, the TiZrNb LRMEA was fabricated by laser melting deposition (LMD) for the first time, and its microstructure and mechanical properties were investigated. The LMD-fabricated TiZrNb LRMEA exhibits a single-phase body-centred-cubic (BCC) structure with an equiaxed grain microstructure, and excellent mechanical properties (with the tensile yield strength of 1185 MPa, a total elongation of 18 % and significant isotropy). This trend represents over a 70 % increase in yield strength compared to its as-cast counterparts, without compromising tensile ductility. The equiaxed grain microstructure is prone to plastic rotational deformation. This feature results in a high density of Geometrically Necessary Dislocations (GNDs), and the accumulation of high-density GNDs increases the strength of the LRMEA. The reduction in the local stress concentration is attributed to the kink bands, which impart the excellent tensile plasticity to the LRMEA. The mechanical properties of the LRMEA are enhanced through multiple mechanisms, including solid-solution strengthening, interstitial-atoms strengthening, and dislocation hardening. The present work provides critical insights into the improvement of mechanical properties in LRMEA using AM, greatly facilitating an understanding of the related mechanisms.

tizrnb基轻质耐火中熵合金（LRMEAs）的一个关键缺陷是屈服强度低，尽管它的密度低，是轻质耐火合金家族中研究最广泛的体系。增材制造（AM）是一种逐层构建物体的技术，能够生产具有高度设计灵活性的复杂金属部件。本文首次采用激光熔化沉积（LMD）法制备了TiZrNb LRMEA，并对其微观结构和力学性能进行了研究。lmd制备的TiZrNb LRMEA具有等轴晶粒组织的单相体心立方（BCC）结构，具有优异的力学性能（抗拉屈服强度为1185 MPa，总伸长率为18%，各向同性显著）。这种趋势表明，与铸态相比，屈服强度提高了70%以上，而不影响拉伸延展性。等轴晶组织容易发生塑性旋转变形。这一特征导致了高密度的几何必要位错（GNDs），高密度GNDs的积累增加了LRMEA的强度。局部应力集中的降低是由于扭结带的存在，扭结带赋予了LRMEA优异的拉伸塑性。LRMEA的力学性能通过固溶强化、间隙原子强化和位错硬化等多种机制得到增强。目前的工作为使用AM改善LRMEA的机械性能提供了重要的见解，极大地促进了对相关机制的理解。

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引用次数: 0

Effect of Nb microalloying on austenitization, continuous cooling transformation behavior and mechanical properties of seismic-resistant rebar Nb微合金化对抗震钢筋奥氏体化、连续冷却转变行为及力学性能的影响

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

Materials Science and Engineering: A

Pub Date : 2026-02-01 DOI: 10.1016/j.msea.2026.149835

Shangkun Wang , Deli Feng , Yongqing Zhang , Yi Luo , Xiangtao Deng

This study systematically examines the austenitization and continuous cooling transformation (CCT) behavior of two 600 MPa grade seismic-resistant rebars, with and without niobium (Nb), to clarify how Nb microalloying governs microstructural evolution and mechanical properties. The results indicate that prior austenite grains (PAGs) in the Nb-bearing steel exhibit two-stage coarsening with increasing austenitization temperature. At lower austenitization temperatures, the two steels show little difference in PAG size. As the austenitization temperature increases, PAGs in the Nb-bearing steel become significantly coarser than those in the Nb-free steel. During cooling, Nb shifts the CCT curves to lower temperatures, delaying ferrite/pearlite transformation and refining the pearlite interlamellar spacing at a given cooling rate. In addition, the Nb-free steel is harder than the Nb-bearing steel under undeformed conditions. After hot deformation, interphase precipitation makes the Nb-bearing steel harder. However, because of competition among microstructural morphologies and phase constituents induced by Nb precipitation, the hardness-cooling rate curves exhibit a crossover. Furthermore, strain-induced precipitation generated by hot deformation and interphase precipitation (IP) bands ahead of migrating phase boundaries pins migrating interfaces and refines the microstructure. Therefore, the combined effects of microstructural refinement and precipitation strengthening increase the yield strength of the Nb-bearing steel from 606 MPa to 665 MPa while maintaining satisfactory ductility.

本研究系统地研究了两种600 MPa级抗震钢筋的奥氏体化和连续冷却转变（CCT）行为，以阐明铌微合金化如何影响微观组织演变和力学性能。结果表明：随着奥氏体化温度的升高，含铌钢中原有奥氏体晶粒呈现两阶段粗化；在较低的奥氏体化温度下，两种钢的PAG尺寸差异不大。随着奥氏体化温度的升高，含铌钢中的pag明显比无铌钢中的pag粗。在冷却过程中，Nb使CCT曲线向较低温度移动，延缓了铁素体/珠光体的转变，并在给定的冷却速率下细化了珠光体的层间间距。此外，在未变形条件下，无铌钢比含铌钢更硬。热变形后，相间析出使含铌钢的硬度增大。然而，由于Nb析出引起的显微组织形态和相成分之间的竞争，硬度冷却速率曲线呈现交叉。此外，热变形产生的应变诱导析出和迁移相边界前的界面析出（IP）带固定了迁移界面并细化了显微组织。因此，显微组织细化和析出强化的联合作用使含铌钢的屈服强度从606 MPa提高到665 MPa，同时保持了满意的延性。

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引用次数: 0

Sensitization and mechanical response of additively manufactured SKD61/17-4PH functionally graded steel: Influence of process parameters, post-AM treatment, and insight into reversed austenite formation 增材制造的SKD61/17-4PH功能梯度钢的敏化和力学响应：工艺参数的影响，am后处理，以及对逆转奥氏体形成的见解

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

Materials Science and Engineering: A

Pub Date : 2026-02-01 DOI: 10.1016/j.msea.2026.149796

Raj Narayan Hajra , Woong Choo , Gargi Roy , Si Mo Yeon , Kyunsuk Choi , Won-Seok Ko , Jeoung Han Kim

This study investigates the phase transformation mechanisms and mechanical behavior of additively manufactured SKD61/17-4 PH graded structure, targeting high-temperature tooling and die applications where thermal stability and strength retention are critical. Using laser powder bed fusion (LPBF), graded structures were fabricated under high- and low-heat-input (HHI and LHI) conditions to examine the effect of processing on solidification and post-annealing response. Electron backscatter diffraction (EBSD), transmission electron microscopy (TEM), and first-principles diffusion analyses revealed that LHI processing promotes δ-ferrite retention through rapid cooling, while HHI favors full austenitization and martensitic transformation. Non-equilibrium solidification induces Ni-C partitioning and Cr solute trapping in austenite, which drive recrystallization and partitioning-assisted γ reversion during annealing at 480 °C. Ni-C enrichment at prior austenite grain boundaries enhances γ nucleation and stress relaxation, whereas Cr-rich δ-ferrite regions foster carbide formation and sensitization upon prolonged exposure. These mechanisms dictate the strength–ductility balance: HHI specimens achieved ultimate tensile strength (UTS) ≈ 1110 MPa and yield strength (YS) ≈ 1000 MPa, while LHI specimens reached UTS ≈ 1250 MPa and YS ≈ 1080 MPa with superior ductility. The findings provide design insights for thermally stable graded steels in demanding industrial environments.

本研究研究了增材制造的SKD61/17-4 PH梯度结构的相变机制和力学行为，目标是热稳定性和强度保持至关重要的高温工装和模具应用。采用激光粉末床熔合（LPBF）技术，在高、低热输入（HHI和LHI）条件下制备了梯度组织，考察了工艺对凝固和退火后响应的影响。电子背散射衍射（EBSD）、透射电镜（TEM）和第一原理扩散分析表明，低温处理通过快速冷却促进了δ-铁素体的保留，而高温处理有利于充分的奥氏体化和马氏体转变。在480℃退火过程中，非平衡凝固诱导了奥氏体中Ni-C的分配和Cr溶质的捕获，导致了再结晶和分配辅助γ还原。Ni-C在奥氏体晶界的富集增强了γ形核和应力松弛，而富cr的δ-铁素体区域在长时间暴露后促进碳化物的形成和敏化。这些机制决定了强度与延性的平衡：HHI试样的极限抗拉强度(UTS)≈1110 MPa，屈服强度(YS)≈1000 MPa，而LHI试样的极限抗拉强度(UTS)≈1250 MPa，屈服强度(YS)≈1080 MPa，具有较好的延性。该研究结果为在苛刻的工业环境中使用热稳定的分级钢提供了设计见解。

{"title":"Sensitization and mechanical response of additively manufactured SKD61/17-4PH functionally graded steel: Influence of process parameters, post-AM treatment, and insight into reversed austenite formation","authors":"Raj Narayan Hajra , Woong Choo , Gargi Roy , Si Mo Yeon , Kyunsuk Choi , Won-Seok Ko , Jeoung Han Kim","doi":"10.1016/j.msea.2026.149796","DOIUrl":"10.1016/j.msea.2026.149796","url":null,"abstract":"<div><div>This study investigates the phase transformation mechanisms and mechanical behavior of additively manufactured SKD61/17-4 PH graded structure, targeting high-temperature tooling and die applications where thermal stability and strength retention are critical. Using laser powder bed fusion (LPBF), graded structures were fabricated under high- and low-heat-input (HHI and LHI) conditions to examine the effect of processing on solidification and post-annealing response. Electron backscatter diffraction (EBSD), transmission electron microscopy (TEM), and first-principles diffusion analyses revealed that LHI processing promotes δ-ferrite retention through rapid cooling, while HHI favors full austenitization and martensitic transformation. Non-equilibrium solidification induces Ni-C partitioning and Cr solute trapping in austenite, which drive recrystallization and partitioning-assisted γ reversion during annealing at 480 °C. Ni-C enrichment at prior austenite grain boundaries enhances γ nucleation and stress relaxation, whereas Cr-rich δ-ferrite regions foster carbide formation and sensitization upon prolonged exposure. These mechanisms dictate the strength–ductility balance: HHI specimens achieved ultimate tensile strength (UTS) ≈ 1110 MPa and yield strength (YS) ≈ 1000 MPa, while LHI specimens reached UTS ≈ 1250 MPa and YS ≈ 1080 MPa with superior ductility. The findings provide design insights for thermally stable graded steels in demanding industrial environments.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"954 ","pages":"Article 149796"},"PeriodicalIF":7.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of microstructural degradation on the hydrogen embrittlement susceptibility and mechanism of a Ni-based single crystalline superalloy 组织退化对ni基单晶高温合金氢脆敏感性的影响及机理

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

Materials Science and Engineering: A

Pub Date : 2026-02-01 DOI: 10.1016/j.msea.2026.149759

Guangxian Lu , Zhixun Wen , Tingting Zhao , Yunsong Zhao , Zhufeng Yue

The microstructural deterioration and hydrogen embrittlement (HE) susceptibility of a Ni-based single crystalline superalloy, which has been subject to long-term thermal exposure (LTE) at 1100 °C (for up to 1000 h), has here been investigated. An LTE-induced microstructural evolution was revealed, including coarsening and rafting of the primary γ′ phase, formation of a dislocation network, and precipitation of the secondary γ′ phase and σ phase. The HE index initially decreased, which was primarily due to hydrogen trapping by new traps. However, it was partially recovered after a prolonged LTE as the σ phase coarsening promoted interfacial H accumulation and decohesion. The H atoms were preferentially trapped in the γ matrix, at the γ/γ′ interface, and in the σ phase. These trapped atoms enhanced the localized plasticity via stacking fault formation in non-aged alloys, while promoting <100> super-dislocations in the LTE samples. The HE mechanism in the superalloys, with and without an LTE treatment, was also elucidated. In addition, the effect of elemental segregation at the γ/γ′ interface on the H-induced damage was also analyzed using first-principles calculations.

本文研究了一种镍基单晶高温合金在1100°C（长达1000 h）的长期热暴露（LTE）下的显微组织劣化和氢脆（HE）敏感性。发现了lte诱导的显微组织演变，包括初级γ′相的粗化和波动，位错网络的形成以及次级γ′相和σ相的析出。HE指数开始下降，这主要是由于新的圈闭捕获氢。然而，经过较长时间的LTE后，由于σ相粗化促进了界面H的积累和脱黏，其部分恢复。H原子优先被捕获在γ基体、γ/γ′界面和σ相中。这些被捕获的原子通过层错的形成增强了非时效合金的局部塑性，同时促进了LTE样品中的<；100>；超位错。研究了高温合金中经过和没有经过LTE处理的HE机理。此外，利用第一性原理计算分析了γ/γ′界面元素偏析对h损伤的影响。

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引用次数: 0

Grain boundary decohesion as the mechanistic origin of hydrogen embrittlement in tungsten explored through an experimental–computational framework 通过实验-计算框架探讨了晶界脱黏作为钨中氢脆的机制起源

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

Materials Science and Engineering: A

Pub Date : 2026-02-01 DOI: 10.1016/j.msea.2026.149804

Halil Yilmaz , Cem Örnek , Beste Payam , Daniel Hallmann

This study demonstrates that hydrogen embrittlement in tungsten is dominated by intergranular brittle fracture arising from hydrogen segregation to grain boundaries, rather than by lattice-based decohesion (HEDE) or localised plasticity (HELP). Through an integrated approach of electrochemical hydrogen charging, mechanical testing, and first-principles calculations, we show that hydrogen insertion into the tungsten lattice is thermodynamically unfavourable, whereas segregation to grain boundaries is exothermic and leads to deep trapping. Each trapped hydrogen atom reduces the grain boundary fracture energy by ∼1 J/m², and high concentrations lead to spontaneous decohesion. Mean-field elasticity modelling indicates that low levels of hydrogen (up to 55 wppm) increase stiffness, while higher concentrations induce elastic softening and instability. Experimentally, hydrogen-charged samples show premature fracture and intergranular cracking, supporting a grain-boundary-controlled fracture mode. Although hydrogen diffusion is rapid in a defect-free lattice (∼10⁻¹⁰ m²/s), it is strongly suppressed in the presence of microstructural traps (∼10⁻²⁷ m²/s), indicating that transport is governed by defect networks rather than bulk solubility. These findings establish a clear mechanistic pathway for hydrogen embrittlement in tungsten, highlighting grain boundary engineering as a critical design strategy for hydrogen-resilient nuclear materials.

该研究表明，钨的氢脆主要是由氢偏析到晶界引起的晶间脆性断裂，而不是由晶格基脱黏（HEDE）或局部塑性（HELP）引起的。通过电化学充氢、力学测试和第一性原理计算的综合方法，我们表明氢插入钨晶格在热力学上是不利的，而向晶界的偏析是放热的，并导致深捕获。每个捕获的氢原子使晶界断裂能降低约1 J/m2，高浓度会导致自发脱粘。平均场弹性模型表明，低水平的氢（高达55 wppm）会增加刚度，而高浓度的氢会导致弹性软化和不稳定。实验结果表明，含氢试样表现出过早断裂和晶间断裂，支持晶界控制断裂模式。尽管氢在无缺陷晶格中扩散迅速（~ 10−10 m2/s），但在存在微观结构陷阱（~ 10−27 m2/s）时，它被强烈抑制，这表明传输是由缺陷网络而不是体溶解度控制的。这些发现为钨的氢脆建立了明确的机制途径，突出了晶界工程作为氢弹性核材料设计的关键策略。

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引用次数: 0

Nanostructural design to enhance the bendability of ultra-high-strength Cu-3.5Ti-0.22Fe alloys: A novel precipitation mechanism of the β-Cu4Ti phase 提高超高强度Cu-3.5Ti-0.22Fe合金可弯曲性的纳米结构设计：β-Cu4Ti相的新析出机制

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

Materials Science and Engineering: A

Pub Date : 2026-02-01 DOI: 10.1016/j.msea.2026.149822

Yunqing Zhu , Lijun Peng , Zaiyan Shang , Songbai Hong , Feng Liu , Kuaishe Wang , Junsheng Wu , Haofeng Xie

This study proposes a strategy to resolve the inherent strength-bendability trade-off in Cu-Ti-Fe alloys. In-situ TKD and TEM reveal a new precipitation mechanism for the β-Cu₄Ti phase. After aging treatment, the minimum bending ratio (r_min/t) decreased from 9.05 to 0.89, while the hardness increased from 319 HV to 364 HV.

本研究提出了一种解决Cu-Ti-Fe合金固有强度-弯曲性权衡的策略。原位TKD和TEM揭示了β-Cu4Ti相的一种新的析出机制。时效处理后，最小弯曲比（rmin/t）由9.05降低到0.89，硬度由319 HV提高到364 HV。

引用次数: 0

Tailoring the microstructure and properties of a lean duplex stainless steel via partitioning of nitrogen 通过氮的分配来调整精益双相不锈钢的组织和性能

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

Materials Science and Engineering: A

Pub Date : 2026-02-01 DOI: 10.1016/j.msea.2026.149823

Rui Wang , Tianyi Chang , Fenghao Li , Zhiyue Shi , Yan Kang , Yong Hu , Jing Fan , Yuhong Zhao , Gang Wang , Jürgen Eckert , Guoping Li , Zhijie Yan

The application of duplex stainless steel (DSS) with a high content of nickel is limited due to its high cost. In the present work, a lean DSS was designed by replacing partial Ni with N, and the microstructure and mechanical properties were tailored via partitioning of nitrogen during the solution treatment process. The results show that increasing the solution temperature leads to a gradual rise in the volume fraction of ferrite and a decrease in that of austenite. During the solution treatment process, the Cr₂N nitrides precipitate in ferrite at the higher solution temperatures (1150–1250 °C), while the secondary austenite forms at the lower temperatures (1000–1100 °C). The competitive precipitation between the nitrides and secondary austenite is mainly due to the partitioning of nitrogen. Mechanical tests indicate that the tensile elongation and impact toughness reach the peak values after the solution treatment at the temperature of 1050 °C; however, they decline with increase of the solution temperature due to the formation of the excessive ferrite and nitrides. Additionally, the yield and tensile strengths show a trend of initial decrease and then increase with rise of the solution treatment temperature, which is attributed to the tailored microstructure, i.e., the fraction ratio of ferrite to austenite and the quantity of precipitates.

高含镍双相不锈钢（DSS）成本高，限制了其应用。在本研究中，通过用N代替部分Ni来设计精益DSS，并在固溶过程中通过氮的分配来定制显微组织和力学性能。结果表明：随着固溶温度的升高，铁素体体积分数逐渐升高，奥氏体体积分数逐渐降低；固溶过程中，Cr2N氮化物在较高固溶温度（1150 ~ 1250℃）下析出铁素体，在较低固溶温度（1000 ~ 1100℃）下形成次生奥氏体。氮化物与次生奥氏体的竞争析出主要是由于氮的分配。力学试验表明，在1050℃固溶处理后，拉伸伸长率和冲击韧性达到峰值；但随着温度的升高，由于过量铁素体和氮化物的形成，它们逐渐下降。随着固溶温度的升高，屈服强度和抗拉强度呈现先降低后升高的趋势，这与铁素体与奥氏体的分数比和析出相数量的调整有关。

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引用次数: 0

Microstructural anisotropy in high-strength Al alloy processed by laser powder bed fusion: Influencing mechanism on mechanical properties and related control strategy 激光粉末床熔合高强铝合金的组织各向异性：影响力学性能的机理及控制策略

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

Materials Science and Engineering: A

Pub Date : 2026-02-01 DOI: 10.1016/j.msea.2026.149773

Jinming Xing, Dongdong Gu, Han Zhang, Keyu Shi, Ruiqi Wang, Miao Chang, Longhai Hu, Kuanyang Feng, Menghuan Yin, Xuechun Hei

The Al-Mn-Mg-Sc-Zr alloy fabricated by laser powder bed fusion (LPBF) exhibits excellent specific strength and thermal stability. However, the mechanical property discrepancies caused by its microstructural anisotropy have not been systematically elucidated, and effective control strategies are lacking. This study systematically investigates the influence mechanism of microstructural anisotropy on the mechanical properties of LPBF-fabricated Al-5.15Mn-1.07Mg-0.72Sc-0.36Zr alloy and proposes targeted control strategy. The results indicate that the performance degradation of vertical specimens stems from the synergistic effect of the equiaxed/columnar bimodal heterogeneous structure and large-sized Al₆Mn phases, which collectively induce premature yielding and a decrease in elongation. By reducing the laser energy density to 77 J/mm³, isotropic mechanical properties were achieved in both the as-printed and heat-treated states. This improvement is attributed to the high cooling rate suppressing the precipitation and growth of secondary phases, as well as the refined melt pool and increased fraction of equiaxed grains delaying crack initiation. This study clarifies the microscopic mechanism of anisotropy and achieves performance regulation through process optimization, laying a theoretical and practical foundation for the preparation of high-performance isotropic aluminum alloys.

采用激光粉末床熔合法制备的Al-Mn-Mg-Sc-Zr合金具有优异的比强度和热稳定性。然而，由于其微观结构各向异性导致的力学性能差异尚未得到系统的阐明，缺乏有效的控制策略。本研究系统研究了组织各向异性对lpbf制备Al-5.15Mn-1.07Mg-0.72Sc-0.36Zr合金力学性能的影响机理，并提出了有针对性的控制策略。结果表明：纵向试样的性能退化是由等轴/柱状双峰非均相组织和大尺寸Al6Mn相的协同作用造成的，它们共同导致了过早屈服和伸长率下降；通过将激光能量密度降低到77 J/mm3，在打印状态和热处理状态下均实现了各向同性的力学性能。这主要是由于高冷却速率抑制了二次相的析出和长大，以及精炼的熔池和增加的等轴晶比例延迟了裂纹的起裂。本研究阐明了各向异性的微观机理，并通过工艺优化实现了性能调控，为制备高性能各向同性铝合金奠定了理论和实践基础。

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引用次数: 0