Materials Science and Engineering: A最新文献_第7页

Microstructural gradients and associated mechanical properties in the rapid solidification microstructure of hypo-eutectic Al-10at.%Cu obtaining after scanned-laser melting 亚共晶Al-10at快速凝固组织的组织梯度及相关力学性能。扫描激光熔化后获得的%Cu

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.2026.149818

M.T. Alamoudi , J.M.K. Wiezorek

Scanned-laser surface melting strategies have been developed to establish morphologically graded rapid solidification (RS) microstructures in bulk alloy specimens of hypoeutectic Al-10Cu. Using electron microscopy and instrumented nanoindentation location-specific mechanical properties have been determined for three morphologically distinct RS microstructure regions that are characterisitic of Al-10Cu, i.e., the transition, α-cell and banded-grain zone. RS microstructure and mechanical property evolution in response to isothermal annealing (120 s ≤ t ≤ 480 s; 180 °C < T ≤ 280 °C) are reported and discussed. Melt pools induced by single-pass scans showed evidence of Marangoni-effect driven mixing and uneven composition retained in the melt. Multi-pass scans and using multiple scan speeds, 1 m/s ≤ v_b ≤ 4 m/s, produced compositionally more uniform melts before forming RS microstructures exhibiting the three morphologically distinct zones. Nanoindentation hardness of the transition, α-cell and banded-grain zones, increased from 2.7 GPa to 3.3 GPa and up to 3.4 GPa, respectively. Annealing caused an initial hardening response attributed to precipitation reactions, followed by moderate coarsening and up to ∼15 % hardness drop. Since the morphologically distinct RS microstructures zones in Al-Cu alloys form for characteristic composition specific solidification velocities, this study illustrates how properties correlate with solidification microstructure selection maps and assists development of processing schema for tayloring properties in Al–Cu parts prepared by laser melting processes.

采用扫描激光表面熔化策略，在亚共晶Al-10Cu大块合金试样中建立了形貌梯度快速凝固（RS）组织。利用电子显微镜和纳米压痕定位仪器测定了Al-10Cu的三个不同的RS微观结构区域，即过渡区、α-细胞区和带状晶粒区。报道并讨论了等温退火（120 s≤t≤480 s; 180°C < t≤280°C）对RS组织和力学性能的响应。单次扫描引起的熔池显示了马兰戈尼效应驱动的混合和熔体中不均匀成分的证据。多道次扫描和采用1 m/s≤vb≤4 m/s的多种扫描速度，在形成具有三个不同形态区域的RS显微组织之前，产生了成分更均匀的熔体。α-细胞区和带状晶区的纳米压痕硬度分别从2.7 GPa提高到3.3 GPa和3.4 GPa。退火引起了最初的硬化反应，这是由于析出反应，随后是适度的粗化和高达15%的硬度下降。由于Al-Cu合金在特定成分的凝固速度下形成了不同的RS显微组织区域，因此本研究阐明了性能与凝固微观组织选择图的关系，并有助于开发激光熔化制备Al-Cu零件的泰勒化性能的加工方案。

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引用次数: 0

Achieving synergistic strengthening of selective laser melted titanium alloy with CoCrFeNi medium-entropy alloy 选择性激光熔化钛合金与CoCrFeNi中熵合金的协同强化

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

Materials Science and Engineering: A

Pub Date : 2026-03-01 Epub Date: 2026-02-05 DOI: 10.1016/j.msea.2026.149897

Laiba Shaukat , Yizhou Tang , Yifeng Xiong , Faming Zhang

Additive manufacturing of titanium matrix composites is often limited by particles-matrix interfacial mismatch. Here, CoCrFeNi medium-entropy alloy (MEA) powder was co-processed with Ti-6Al-4V (Ti64) via selective laser melting (SLM) to enable in-situ alloying rather than discrete particle reinforcement. The SLM thermal cycle drives near-complete dissolution of the MEA and produces a nanoscale dual-phase architecture of acicular α′ martensite and metastable β. Electron backscatter diffraction EBSD reveals a chemically homogeneous yet mechanically heterogeneous α′/β dual-phase microstructure with random texture and reduced lattice strain, indicating suppressed epitaxial growth and refined phase distribution. Mechanical properties are significantly enhanced: the 3 wt% MEA composition achieves an ultimate tensile strength of 1411 MPa with 8.2% elongation, alongside concurrent increases in yield strength and hardness. Strength-ductility synergy arises from the cooperative action of transformation-induced plasticity (TRIP), hetero-deformation-induced (HDI) strengthening, associated with α′/β mechanical contrast, and extreme grain refinement, with plasticity partitioned across α′/β interphase boundaries and dislocation-rich cellular structures. By eliminating discrete reinforcement/matrix interfaces, this in-situ alloying route circumvents the conventional interfacial constraint in TMCs and provides a viable pathway for designing high-performance Ti-based composite.

钛基复合材料的增材制造常常受到颗粒-基体界面失配的限制。本文采用选择性激光熔化（SLM）技术对CoCrFeNi中熵合金（MEA）粉末与Ti-6Al-4V （Ti64）进行共加工，实现原位合金化而不是离散颗粒强化。SLM热循环驱动MEA几乎完全溶解，形成针状α′马氏体和亚稳β的纳米级双相结构。电子背散射衍射显示了一种化学均匀但力学不均匀的α′/β双相微观结构，具有随机织构和减小的晶格应变，表明外延生长受到抑制，相分布精细。机械性能显著增强：3 wt%的MEA成分达到了1411 MPa的极限拉伸强度和8.2%的伸长率，同时屈服强度和硬度也得到了提高。强度-延性协同作用源于相变诱导塑性（TRIP）、异质变形诱导强化（HDI）（与α′/β力学对比相关）和极端晶粒细化的共同作用，塑性分布在α′/β相界面和富含位错的细胞结构上。通过消除离散的增强/基体界面，这种原位合金化路线绕过了传统的tmc界面约束，为设计高性能的ti基复合材料提供了一条可行的途径。

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引用次数: 0

Corrigendum to “The effect of prior austenite grain size on hierarchical structures of lath martensite in a 22MnB5 steel” [Mater. Sci. Eng. A 951 (2026) 149544] “奥氏体晶粒尺寸对22MnB5钢板条马氏体分层组织的影响”的勘误[材料]。科学。Eng。A 951 (2026) 149544]

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

Materials Science and Engineering: A

Pub Date : 2026-03-01 Epub Date: 2026-02-17 DOI: 10.1016/j.msea.2026.149914

Chien-Yu Tseng , Ming-Yi Cheng , Tzu-Ching Tsao , Po-Han Chiu , Yu-An Chen , Chu-Jen Chen , R.D.K. Misra , Yo-Lun Yang , Te-Cheng Su , Chih-Yuan Chen , Jer-Ren Yang

引用次数: 0

High-performance soldering achieved through an energy-efficient magnetic field-assisted microwave hybrid joining: A multiscale study via molecular dynamics and first-principles calculations 通过高能效磁场辅助微波混合连接实现高性能焊接：通过分子动力学和第一性原理计算的多尺度研究

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

Materials Science and Engineering: A

Pub Date : 2026-03-01 Epub Date: 2026-02-12 DOI: 10.1016/j.msea.2026.149915

Shuai Zhang , Chen Zeng , Zhehao Gan , Jinhong Liu , Peng He , Tianran Ding , Weimin Long , Sujuan Zhong , Yew-Hoong Wong , Shuye Zhang

To advance high-reliability and sustainable electronic packaging, this study proposes a magnetic field-assisted microwave hybrid joining (MMHJ) strategy. By incorporating Ni@Sn nanoparticles and Ni-plated carbon fibers (CF@Ni@Sn) into a Sn-3Ag-0.5Cu (SAC305) matrix, we systematically investigated the magnetoelectric response of the composite solder, with particular emphasis on grain orientation kinetics and microstructural evolution. Under a customized longitudinal magnetic field, the CF reinforcements achieved precise directional alignment, while Ni solute segregation was effectively suppressed. This synergetic modulation promoted β-Sn grain refinement and a substantial increase in dislocation density. Utilizing a 2 kW microwave field (f = 2.45 GHz), the MMHJ-processed composite joints attained a peak shear strength of 58.58 MPa within a 40 s duration-a 30.41% improvement over conventional SAC305 while slashing energy consumption by 93.92%. After 1200 thermal cycles, the MMHJ-Cu/SAC-0.5NCF@/Cu joints retained a 26.61% strength advantage, highlighting their excellent service durability. Mechanistically, the non-equilibrium interactions within the microwave-reinforcement architecture were analyzed through dielectric and magnetic tensor analysis. By integrating molecular dynamics (MD) simulations of interfacial atomic flux with DFT-based field perturbation theory, the regulatory role of thermoelectromagnetic hydrodynamic (TEMHD) effects on intermetallic compound (IMC) morphogenesis was revealed. These multiscale insights establish a rigorous physical foundation for the experimentally observed advances in high-efficiency soldering.

为了提高电子封装的高可靠性和可持续性，本研究提出了一种磁场辅助微波混合连接（MMHJ）策略。通过将Ni@Sn纳米颗粒和镀镍碳纤维（CF@Ni@Sn）结合到Sn-3Ag-0.5Cu （SAC305）基体中，我们系统地研究了复合钎料的磁电响应，特别强调了晶粒取向动力学和微观结构演变。在自定义的纵向磁场下，CF增强材料实现了精确的定向取向，同时有效地抑制了Ni溶质偏析。这种协同调制促进了β-Sn晶粒的细化和位错密度的显著增加。利用2 kW的微波场（f = 2.45 GHz）， mmhj加工的复合材料接头在40 s的持续时间内达到了58.58 MPa的峰值抗剪强度，比传统SAC305提高了30.41%，同时降低了93.92%的能耗。经过1200次热循环后，MMHJ-Cu/SAC-0.5NCF@/Cu接头仍保持了26.61%的强度优势，突出了其优异的使用耐久性。力学上，通过介电张量和磁张量分析了微波增强结构内部的非平衡相互作用。通过将分子动力学（MD）界面原子通量模拟与基于dft的场摄动理论相结合，揭示了热电磁流体动力学（TEMHD）效应对金属间化合物（IMC）形态发生的调控作用。这些多尺度的见解为实验观察到的高效焊接进展奠定了严格的物理基础。

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引用次数: 0

The influence of rolling on the microstructure, mechanical properties, and in vitro degradation of biomedical Zn-2Cu alloy treated by ultrasound 轧制对超声处理医用Zn-2Cu合金显微组织、力学性能及体外降解的影响

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

Materials Science and Engineering: A

Pub Date : 2026-03-01 Epub Date: 2026-02-13 DOI: 10.1016/j.msea.2026.149920

Weibin Cui , Qinglin Li , Jing Yang , Yirui Zhang , Hongkai Qiao , Pengtao Zhang

Zn alloys are considered ideal materials for in vivo implants owing to their moderate degradation rates. The addition of Cu significantly enhances the antibacterial properties of Zn-Cu alloys, making them suitable for degradable implants such as orthopedic bone plates and bone screws. However, cast Zn-Cu alloys exhibit a poor strength-plasticity balance, which limits their ability to meet the mechanical performance requirements of bone implants. This study combined ultrasonic treatment with rolling processes to systematically investigate the microstructural evolution, mechanical properties, and degradation behavior of Zn-2Cu alloys prepared under different rolling conditions. The results revealed that after rolling, the α-Zn grains was significant refined into equiaxed grains with average sizes of 474 nm, 613 nm, and 591 nm. Additionally, sub-micron fine CuZn₅ precipitates formed, with average sizes of 610.7 nm, 503.9 nm, and 568.8 nm. Tensile tests revealed that 5-pass rolling at 200 °C significantly improved the mechanical properties of Zn-2Cu alloys compared with the unrolled condition. The ultimate tensile strength (UTS), yield strength (YS), and elongation (El) were increased from 178 MPa, 161 MPa, and 3.01% to 378 MPa, 367 MPa, and 58.1%, respectively. Electrochemical polarization tests indicated that the 5-pass heat-rolled (HR-5), 5-pass cold-rolled (CR-5), and 2-pass heat-rolled (HR-2) alloys in Hank's solution exhibited degradation rates of 1.865 mm/year, 0.418 mm/year, and 1.207 mm/year, respectively. After 7 days of immersion corrosion in Hank's solution, the degradation rates followed the order of HR-5 (35.94 μm/year) > HR-2 (20.06 μm/year) > CR-5 (25.08 μm/year). These results suggested that multi-process composite regulation can achieve an optimal balance between alloy strength and plasticity. This study provides a theoretical and technical basis for designing and fabricating next-generation biodegradable Zn alloy implants and highlights their potential applications in orthopedic medical devices.

锌合金由于其适度的降解率被认为是体内植入物的理想材料。Cu的加入显著提高了Zn-Cu合金的抗菌性能，使其适用于骨科骨板和骨螺钉等可降解植入物。然而，铸造Zn-Cu合金表现出较差的强度-塑性平衡，这限制了它们满足骨植入物力学性能要求的能力。本研究将超声处理与轧制工艺相结合，系统研究了不同轧制条件下制备的Zn-2Cu合金的显微组织演变、力学性能和降解行为。结果表明：轧制后α-Zn晶粒明显细化为平均尺寸为474 nm、613 nm和591 nm的等轴晶；形成亚微米级CuZn5细相，平均尺寸分别为610.7 nm、503.9 nm和568.8 nm。拉伸试验表明，在200℃下进行5道次轧制，与未轧制相比，Zn-2Cu合金的力学性能得到了显著改善。拉伸强度（UTS）、屈服强度（YS）和伸长率（El）分别从178 MPa、161 MPa和3.01%提高到378 MPa、367 MPa和58.1%。电化学极化试验表明，5道次热轧（HR-5）、5道次冷轧（CR-5）和2道次热轧（HR-2）合金在Hank’s溶液中的降解率分别为1.865 mm/年、0.418 mm/年和1.207 mm/年。在Hank’s溶液中浸泡腐蚀7 d后，降解速率依次为HR-5 （35.94 μm/年）> HR-2 （20.06 μm/年）> CR-5 （25.08 μm/年）。结果表明，多工序复合调节可以达到合金强度和塑性的最佳平衡。本研究为下一代生物可降解锌合金植入物的设计和制造提供了理论和技术基础，并强调了其在骨科医疗器械中的潜在应用。

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引用次数: 0

Microstructure-controlled low-cycle fatigue of 2026 Al alloy in T4 and T6 tempers: roles of SⅠ precipitates and grain-boundary GBPs / PFZs 2026铝合金T4和T6回火组织控制的低周疲劳：SⅠ相和晶界GBPs / pfz的作用

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.2026.149884

Wenbin Zhang , Huizhong Li , Xiaopeng Liang , Zhengfeng Lv , Zhiyuan Cheng , Zhaohui Yan , Xiaofen Tan

The 2026 aluminum alloy is a damage-tolerant structural material for aerospace applications, where low-cycle fatigue (LCF) resistance is critical to structural safety. In this work, strain-controlled LCF tests with strain amplitudes of 0.6%–0.9% were performed on a 2026 Al alloy in two typical tempers (T4 and T6), and the fatigue behavior was correlated with microstructural evolution. The fatigue life was evaluated using the Coffin–Manson relationship, while an energy-based hysteresis model was employed to extract the intrinsic fatigue damage capacity W₀ and the damage-transition exponent β. The T4 temper exhibits more homogeneous intragranular deformation, assisted by dispersed quenched-in dislocation loops and thermally stable Al₃Zr dispersoids, together with the absence of grain-boundary precipitates, leading to a microvoid-dominated damage mode. Consequently, the T4 temper shows high fatigue ductility (εf' = 17.3, c = −1.44) and a higher damage capacity (W₀ = 2511 × 10⁶ J/m³). In contrast, the T6 temper contains a high density of shearable S_Ⅰ precipitates, which sustain a higher fatigue strength (σf' = 1127 MPa) but promote localized cyclic deformation and microcrack-dominated damage with subsurface crack initiation. Within the energy-based framework, the larger β in the T6 temper indicates a more nonlinear conversion from cyclic hysteresis work to effective damage under localized deformation, consistent with its crack-initiation mode. These results clarify the distinct roles of S_Ⅰ precipitates and intragranular dislocation-loop / Al₃Zr features in controlling LCF response, providing guidance for tailoring temper states of Al–Cu–Mg alloys for different fatigue-service scenarios.

2026铝合金是一种用于航空航天应用的耐损伤结构材料，在航空航天应用中，抗低周疲劳（LCF）对结构安全至关重要。本文对2026铝合金在T4和T6两种典型回火状态下进行应变控制的应变幅值为0.6% ~ 0.9%的LCF试验，疲劳行为与显微组织演变相关。采用Coffin-Manson关系评价疲劳寿命，采用基于能量的迟滞模型提取本征疲劳损伤能力W0和损伤转变指数β。T4回火表现出更均匀的晶内变形，分散的淬火位错环和热稳定的Al3Zr弥散体，以及晶界沉淀的缺失，导致微孔洞为主的损伤模式。因此，T4回火具有较高的疲劳延展性（εf′= 17.3,c = - 1.44）和较高的损伤能力（W0 = 2511 × 106 J/m3）。相反，T6回火含有高密度的可剪切SⅠ相，具有较高的疲劳强度（σf′= 1127 MPa），但促进局部循环变形和微裂纹为主的损伤，并伴有次表面裂纹萌生。在基于能量的框架内，T6回火的β值越大，表明在局部变形下，从循环迟滞功到有效损伤的非线性转换越明显，这与T6回火的裂纹起裂模式一致。这些结果阐明了SⅠ析出相和晶内位错环/ Al3Zr特征在控制LCF响应中的独特作用，为定制不同疲劳工况下Al-Cu-Mg合金的回火状态提供了指导。

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引用次数: 0

TiC nanoparticles tune phase stability and deformation mechanisms in directed energy deposition processed Fe60Co15Ni15Cr10 medium-entropy alloy composites TiC纳米颗粒调节定向能沉积制备Fe60Co15Ni15Cr10中熵合金复合材料的相稳定性和变形机制

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

Materials Science and Engineering: A

Pub Date : 2026-03-01 Epub Date: 2026-01-27 DOI: 10.1016/j.msea.2026.149839

Soung Yeoul Ahn , Eun Seong Kim , Sang Guk Jeong , Stefanus Harjo , Takuro Kawasaki , Wu Gong , Hyun-Joong Kim , Soon-Jik Hong , Sun Ig Hong , Hyeonseok Kwon , Jung Gi Kim , Hyoung Seop Kim

Additive manufacturing (AM) of particle-reinforced metal matrix composites (MMCs) offers opportunities not only for mechanical strengthening but also for tailoring matrix phase stability and deformation behavior. In this study, TiC (2 wt%) nanoparticles were incorporated into Fe₆₀Co₁₅Ni₁₅Cr₁₀ (at%) medium-entropy alloy (MEA) using directed energy deposition (DED) process. Despite the severe thermal conditions of the DED process, a substantial fraction of TiC remained, while partial decomposition released C and Ti elements into the matrix. This chemical modification stabilized the γ-austenite matrix phase and suppressed deformation-induced martensitic transformation (DIMT), which is typically active in the Fe₆₀Co₁₅Ni₁₅Cr₁₀ MEA. Instead, the composite exhibited a transition toward slip-dominated deformation. Microstructural observation revealed that dispersed and semi-coherent TiC particles, together with solute partitioning from decomposed nanoparticles, altered grain boundary morphology and promoted distributed plastic flow. In-situ neutron diffraction accompanied with tensile test confirmed enhanced dislocation activity in the early stage of deformation, supporting the deformation mechanism shift from DIMT-assisted hardening to dislocation-mediated slip. These results highlight the critical role of nanoparticle-induced phase stability variation in governing deformation mechanisms, offering new insights into designing AM-processed MMCs beyond conventional strength-oriented strategies.

颗粒增强金属基复合材料（MMCs）的增材制造（AM）不仅提供了机械强化的机会，而且还提供了定制基体相稳定性和变形行为的机会。在本研究中，采用定向能沉积（DED）工艺将TiC （2 wt%）纳米颗粒掺入Fe60Co15Ni15Cr10 （at%）中熵合金（MEA）中。尽管DED过程的热条件恶劣，但仍有相当一部分TiC残留，而部分分解将C和Ti元素释放到基体中。该化学改性稳定了γ-奥氏体基体相，抑制了形变诱导马氏体相变（DIMT），该相变在Fe60Co15Ni15Cr10 MEA中具有典型的活性。相反，复合材料表现出向滑移主导变形的转变。显微组织观察表明，TiC颗粒分散、半共融，分解后溶质分块，改变了晶界形态，促进了分布塑性流动。原位中子衍射和拉伸试验证实变形初期位错活动性增强，支持变形机制由dimt辅助硬化向位错介导滑移转变。这些结果强调了纳米颗粒诱导的相稳定性变化在控制变形机制中的关键作用，为设计am加工的mmc提供了超越传统强度导向策略的新见解。

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引用次数: 0

Hydrogen embrittlement and mechanical response of 304L steel with ZrC additions 添加ZrC后304L钢的氢脆及力学响应

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

Materials Science and Engineering: A

Pub Date : 2026-03-01 Epub Date: 2026-01-27 DOI: 10.1016/j.msea.2026.149824

A. Stubbers , B.P. Rocky , C. Gilleland , R. Shrestha , C. San Marchi , R.P. Wilkerson , G.B. Thompson , C.R. Weinberger

While stainless steels are widely used for hydrogen storage infrastructure, they can still be vulnerable to hydrogen embrittlement justifying the need to further improve their hydrogen resiliency. Here, we investigate the potential for transition metal carbide additions to improve the hydrogen compatibility of austenitic stainless steels. ZrC nanoparticles were dispersed in contents of 0.01–10 wt% in 304 L stainless steel powder, mixed via high energy ball milling, and subsequently consolidated using direct current sintering. To assess hydrogen compatibility, the tensile properties of similarly processed 304 L without ZrC nanoparticles were compared to 304 L with the ZrC additions; both materials were evaluated prior to and after hydrogen exposure (non-charged and H-precharged, respectively). Depending upon the ZrC phase fraction, the yield strengths varied from ∼325 to 560 MPa in the non-charged condition and from ∼375 to 550 MPa in the H-precharged condition. Strain at failure varied from ∼5 to 90 % and from ∼5 to 35 % in the non-charged and hydrogen-precharged conditions, respectively. Results from stress-strain profiles demonstrate limited efficacy of ZrC as a method to mitigate hydrogen embrittlement entirely but does demonstrate the potency of ZrC inclusions as strengthening addition to 304 L alloys without a loss of ductility.

虽然不锈钢广泛用于储氢基础设施，但它们仍然容易受到氢脆的影响，因此需要进一步提高其氢弹性。在这里，我们研究了添加过渡金属碳化物以改善奥氏体不锈钢的氢相容性的可能性。ZrC纳米颗粒以0.01 ~ 10 wt%的质量分数分散在304 L不锈钢粉中，通过高能球磨混合，然后用直流烧结固结。为了评估氢相容性，将未添加ZrC纳米粒子的304 L与添加ZrC纳米粒子的304 L进行了拉伸性能比较；两种材料在氢气暴露之前和之后（分别为未充电和预充氢）进行评估。根据ZrC相分数的不同，未充电条件下的屈服强度从~ 325到560mpa不等，h预充电条件下的屈服强度从~ 375到550mpa不等。在未充电和预充氢条件下，失效时的应变变化范围分别为~ 5 ~ 90%和~ 5 ~ 35%。应力-应变曲线的结果表明，ZrC作为一种完全减轻氢脆的方法的效果有限，但确实证明了ZrC夹杂物作为304 L合金的强化物而不损失延性的效力。

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引用次数: 0

Correcting oxygen-impurity artifacts in refractory alloys: A case study of the V-Zr system 纠正难熔合金中的氧杂质伪影：以V-Zr体系为例

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

Materials Science and Engineering: A

Pub Date : 2026-03-01 Epub Date: 2026-02-09 DOI: 10.1016/j.msea.2026.149906

Yu-Ning Chiu , Shao-Yu Yen , Wei-Chen Wu , Shih-Kang Lin

Vanadium (V) and zirconium (Zr) exhibit significant mechanical properties at elevated temperatures, making them promising candidates for the development of high-temperature alloys. While the phase diagram and thermodynamic modeling of the V-Zr binary system have been extensively studied, an ambiguous phase boundary of the bcc-(Zr) phase remains unconfirmed due to the absence of experimental data. The challenges in precisely determining phase equilibria in the bcc-(Zr) phase-related field can be attributed to two main factors: (1) susceptibility of the bcc-(Zr) phase to trace oxygen content in alloys, potentially leading to over/underestimation of phase compositions during characterizations, and (2) the transformation of the bcc-(Zr) phase into the meta-stable ω-phase via a diffusionless phase transformation during quenching, posing difficulties in phase identifications. In this study, phase equilibria experiments were conducted to determine the phase boundary of the bcc-(Zr) phase and the relevant invariant reactions. Yttrium (Y) was added to the alloys to serve as a getter, removing oxygen (O) content from the bcc-(Zr) phase. The addition of Y effectively captured trace O in the alloys, forming Y-oxide and preventing O from impacting the phase equilibria of the V-Zr system at elevated temperatures. Combining key experimental results with ab initio calculations, a self-consistent thermodynamic description of the V-Zr binary system was optimized and proposed.

钒(V)和锆（Zr）在高温下表现出显著的力学性能，使它们成为开发高温合金的有希望的候选者。虽然V-Zr二元体系的相图和热力学模型已经得到了广泛的研究，但由于缺乏实验数据，bcc-(Zr)相的相界仍然不明确。在bcc-(Zr)相相关场中精确测定相平衡的挑战可归因于两个主要因素：(1)bcc-(Zr)相对合金中痕量氧含量的敏感性，可能导致表征过程中相成分的高估或低估；(2)bcc-(Zr)相在淬火过程中通过无扩散相变转变为亚稳定的ω相，给相识别带来困难。本研究通过相平衡实验确定了bcc-(Zr)相的相边界及相关的不变量反应。在合金中加入钇(Y)作为吸气剂，去除bcc-(Zr)相中的氧(O)含量。Y的加入有效地捕获了合金中的微量O，形成Y氧化物，防止O在高温下影响V-Zr体系的相平衡。结合关键实验结果和从头计算，优化并提出了V-Zr二元体系的自洽热力学描述。

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引用次数: 0

Alternating columnar-equiaxed heterostructure for superior strength and ductility in laser additive manufactured Co-based alloys 交替柱-等轴异质结构在激光增材制造co基合金中具有优异的强度和延展性

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

Materials Science and Engineering: A

Pub Date : 2026-03-01 Epub Date: 2026-01-31 DOI: 10.1016/j.msea.2026.149869

Zihao Zhang , Mingchuan Li , Yiqun Ren , Shuai Chang , Liqun Li , Yichen Huang , Mingyu Li

The strength-ductility trade-off presents a significant challenge for applying Stellite 6 cobalt-based alloy as a structural material. This study addresses this issue by fabricating a heterostructure (HS) with alternating columnar and equiaxed grain layers in a Stellite 6 alloy via laser additive manufacturing (AM) through precise heat input control. The microstructure, tensile properties, and deformation mechanisms of this heterostructure were systematically investigated and compared with a coarse columnar (CC) structure. Results demonstrate that the HS sample achieved a superior ultimate tensile strength of 1458 MPa and a yield strength of 884 MPa, significantly outperforming the CC sample while maintaining comparable ductility. Load-unload-reload (LUR) tests and microstructural analysis reveal that the enhanced performance is primarily attributed to hetero-deformation induced (HDI) strengthening. Significant HDI stress, generated from the strain incompatibility between the soft columnar and hard equiaxed zones, promotes the accumulation of geometrically necessary dislocations (GNDs) at their interfaces, thereby enhancing the work hardening capability and ultimate strength. This work provides a novel microstructural design strategy for developing high-performance additively manufactured cobalt-based alloys.

在强度和延展性之间的权衡是钨钴钴合金作为结构材料应用的一个重大挑战。本研究通过精确的热输入控制，利用激光增材制造技术（AM）在Stellite 6合金中制造出具有柱状和等轴相间晶粒层的异质结构（HS）。系统地研究了该异质结构的显微组织、拉伸性能和变形机理，并与粗柱状（CC）异质结构进行了比较。结果表明，HS试样的极限抗拉强度为1458 MPa，屈服强度为884 MPa，显著优于CC试样，同时保持了相当的延性。载荷-卸载-重新加载（LUR）试验和显微组织分析表明，性能的增强主要归因于异质变形诱导（HDI）强化。软柱状区和硬等轴区之间的应变不相容产生了显著的HDI应力，促进了两者界面上几何必要位错（GNDs）的积累，从而提高了加工硬化能力和极限强度。这项工作为开发高性能增材制造钴基合金提供了一种新的微结构设计策略。

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