Materials Science and Engineering: A最新文献_第8页

Evolution mechanism of precipitates, mechanical properties, and corrosion behavior in Al-Cu-Li alloys during artificial aging 人工时效过程中Al-Cu-Li合金析出相演化机理、力学性能及腐蚀行为

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

Materials Science and Engineering: A

Pub Date : 2026-01-14 DOI: 10.1016/j.msea.2026.149786

Peng Chen , Wenhao Chen , Jie Wang , Xiong Wen , Yang Tang , Bensheng Huang , Zhiqing Zhang

This study investigates the microstructure-property relationship in Al-Cu-Li alloys through systematic solution treatment and artificial aging treatment (AT) of fully annealed specimens. A comprehensive examination was conducted on the microstructural evolution during aging and its corresponding effects on mechanical properties and corrosion resistance. Microstructure characterization techniques including scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to analyze precipitation behavior, and mechanical properties were evaluated through microhardness measurements and tensile testing. Corrosion resistance was assessed via intergranular corrosion (IGC) tests and electrochemical analysis. The artificial aging process exhibited three distinct hardening stages: (ⅰ) rapid hardening stage (AT-0 to 24 h), (ⅱ) slow hardening stage (AT-24 to 84 h), and (ⅲ) steady hardness stage (>AT-84 h). During the rapid hardening stage, extensive phase transformation from Guinier-Preston Zones (GP zones) to θ′ phases developed, accompanied by an 81.3 % reduction in GPZs density (from 9.67 × 10³ μm⁻² to 1.81 × 10³ μm⁻²) and microhardness increase to 109 HV. The peak-aged condition (AT-84) achieved maximum hardness (134.7 HV) and tensile strength (545 MPa, 40 % increase as compared with the AT-2), though with compromised elongation (9.1%, 55% decrease as compared with the AT-2). Prolonged aging to 120 h (AT-120) further increased strength (563 MPa) but severely reduced ductility (elongation about 5.6%). The limited solute supply during slow hardening decelerated θ′ precipitation kinetics, while steady hardness stage featured coarsening precipitates (exceeding 100 nm) with reduced number density. The formation of grain boundary precipitates (GBPs) and precipitate-free zones (PFZs) was found to deteriorate both mechanical properties and corrosion performance. In the electrochemical tests, the AT-2 exhibits the lowest E_corr and superior corrosion performance. However, the higher density of GP zones in the alloy leads to a higher i_corr and a faster corrosion rate for the AT-2. Extended aging caused cathodic Ecorr shifts, while GBPs and PFZs served as preferential corrosion paths. Furthermore, galvanic coupling between Cu-rich phases and the Cu-depleted matrix promoted localized pitting, accelerating overall corrosion degradation.

通过系统固溶处理和人工时效处理，研究了Al-Cu-Li合金的显微组织与性能关系。对时效过程中微观组织的演变及其对力学性能和耐蚀性的影响进行了全面研究。采用扫描电子显微镜（SEM）和透射电子显微镜（TEM）等微观结构表征技术分析了析出行为，并通过显微硬度测量和拉伸测试评估了力学性能。通过晶间腐蚀（IGC）测试和电化学分析来评估耐蚀性。人工时效过程表现出三个不同的硬化阶段：（ⅰ）快速硬化阶段（AT-0 ~ 24 h），（ⅱ）缓慢硬化阶段（AT-24 ~ 84 h），（ⅲ）稳定硬度阶段（AT-84 h）。在快速硬化阶段，从ginier - preston区（GP区）向θ′相转变，GPZs密度降低81.3%（从9.67 × 103 μm−2降低到1.81 × 103 μm−2），显微硬度提高到109 HV。峰时效态（AT-84）获得了最大硬度（134.7 HV）和抗拉强度（545 MPa，比AT-2提高40%），但伸长率较低（9.1%，比AT-2降低55%）。延长时效至120 h (AT-120)，强度（563 MPa）进一步提高，但延展性严重降低（伸长率约5.6%）。在缓慢硬化阶段，溶质供应的限制减慢了θ′析出动力学，而在稳定硬度阶段，随着数量密度的降低，析出物（超过100 nm）变粗。晶界析出相（GBPs）和无析出带（PFZs）的形成使材料的力学性能和腐蚀性能恶化。在电化学测试中，AT-2表现出最低的Ecorr和优异的腐蚀性能。然而，合金中GP区的密度越高，AT-2的icorr越高，腐蚀速率越快。延长时效导致阴极Ecorr位移，而GBPs和PFZs是优先腐蚀路径。此外，富cu相与贫cu基体之间的电偶联促进了局部点蚀，加速了整体腐蚀降解。

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引用次数: 0

Tailoring nanostructures and mechanical properties of laser direct energy deposited 18Ni300 via induction heat treatment 感应热处理激光直接能沉积18Ni300的纳米结构及力学性能

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

Materials Science and Engineering: A

Pub Date : 2026-01-13 DOI: 10.1016/j.msea.2026.149776

Beibei Zhu, Gaofeng Xu, Li Meng, Qianwu Hu, Xu Liu, Xiaoyan Zeng

This study addresses the critical need for localized strengthening of laser direct energy deposited components by developing an innovative induction heat treatment strategy. Focusing on the deposited 18Ni300 layer of a deposit-substrate composite (20Mn2SiCrMo bainitic steel substrate), a short-time (5–30 min) and high-temperature (600 °C) induction heat treatment was proposed to regulate the precipitate evolution and reversed austenite (RA’) formation of 18Ni300 deposits, the synergistic optimization of the strength/toughness was achieved without affecting the 20Mn2SiCrMo substrate’ performance. During heat treatment, the RA’ preferentially nucleates and grows up at the inter-dendritic α′-M laths, intra-dendritic α′-M laths, subgranular boundaries or near the Ni-rich precipitates; meanwhile, the nano-intermetallic compounds, such as η-Ni₃Ti, Ni₃Mo, and Laves-Fe₂Mo, are precipitated sequentially, and the lattice mismatch degree between them and the parent phase increases with the heating time. This multi-scale synergistic evolution mechanism of microstructure enables the 18Ni300 deposit’ yield strength to be increased by 32.8 % under only 10 min of heating, while keeping the decrease in impact toughness within 16.4 %, reaching 1441 MPa and 77.72 J, respectively. Mechanistic analysis shows that the dynamic balance between the lattice mismatch reinforcement and the TRIP effect of RA’ is the key to achieving the strength-toughness synergy. This technology provides a new paradigm for localized control of bimetallic composites, which is of great value in repaired and remanufacturing components serviced in extreme environments, such as rail transportation and ocean engineering.

本研究通过开发一种创新的感应热处理策略，解决了激光直接能量沉积部件局部强化的关键需求。针对沉积-基体复合材料（20Mn2SiCrMo贝氏体钢基体）中沉积的18Ni300层，提出采用短时间（5-30 min）和高温（600℃）感应热处理来调节18Ni300镀层的析出相演化和逆转奥氏体（RA’）的形成，在不影响20Mn2SiCrMo基体性能的情况下实现强度/韧性的协同优化。在热处理过程中，RA′优先在枝晶间、枝晶内、亚晶边界或富ni析出相附近形核长大；同时，η-Ni3Ti、Ni3Mo、laes - fe2mo等纳米金属间化合物依次析出，且随着加热时间的延长，它们与母相的晶格失配程度增大。这种微观组织的多尺度协同演化机制使18Ni300镀层在加热10 min后屈服强度提高32.8%，冲击韧性下降幅度控制在16.4%以内，分别达到1441 MPa和77.72 J。机理分析表明，晶格错配增强与RA ' TRIP效应之间的动态平衡是实现强韧协同的关键。该技术为双金属复合材料的局部控制提供了一种新的范例，在铁路运输和海洋工程等极端环境下维修和再制造部件具有重要价值。

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引用次数: 0

Effect of Al and Ti addition on precipitation and recrystallization behavior of CrFeNi medium-entropy alloy 添加Al和Ti对CrFeNi中熵合金析出和再结晶行为的影响

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

Materials Science and Engineering: A

Pub Date : 2026-01-13 DOI: 10.1016/j.msea.2026.149767

Lili Ma, Panpan Zhao, Zhengfang Wei, Baiting Yang, Jilan Zhou, Mingmin Zhang, Shouyu Ji

This work investigates the effect of Al and Ti addition on the precipitation and recrystallization behavior of CrFeNi medium-entropy alloy during the aging and cold rolling-recrystallization annealing process. Al and Ti elements significantly encourage the formation of BCC-structured precipitates after aging treatment, which exhibits a peak volume fraction at 800–900 °C and helps to increase strength. Al2Ti1 alloy aging at 900 °C has a yield strength of 696 MPa, which is 221 % higher than the annealed CrFeNi alloy and 225 % higher than the as-cast Al2Ti1 alloy. Due to the introduction of flaws during cold rolling, the volume fraction of precipitates in the annealed CrFeNi alloy greatly increases, resulting in the strength differential between the two annealed alloys being clearly less than that between the two aged alloys. Overall, the yield strength of the Al2Ti1 alloy is consistently higher than that of the CrFeNi alloy. Both the CrFeNi and Al2Ti1 alloys annealed at 800 °C show a considerable strength-plasticity configuration, with a yield strength of 590 MPa and 948 MPa, and an elongation of 24 % and 17 %. The annealed CrFeNi alloy is strengthened by the fine-grain strengthening mechanism, while the annealed Al2Ti1 alloy is primarily strengthened by both the fine-grain and precipitation strengthening. This work thoroughly demonstrates the optimization potential of low-cost FCC-structured medium-entropy alloys and promotes their application in industrial domains.

本文研究了Al和Ti对CrFeNi中熵合金在时效和冷轧再结晶退火过程中析出和再结晶行为的影响。时效处理后，Al和Ti元素显著促进了bcc组织析出相的形成，在800-900℃时析出相的体积分数达到峰值，有利于提高强度。900℃时效Al2Ti1合金的屈服强度为696 MPa，比退火后的CrFeNi合金高221%，比铸态Al2Ti1合金高225%。由于冷轧过程中缺陷的引入，退火后的CrFeNi合金中析出相的体积分数大大增加，导致两种退火合金的强度差明显小于两种时效合金的强度差。总体而言，Al2Ti1合金的屈服强度始终高于CrFeNi合金。800℃退火后的CrFeNi和Al2Ti1合金均表现出良好的强度塑性结构，屈服强度分别为590 MPa和948 MPa，伸长率分别为24%和17%。退火后的CrFeNi合金以细晶强化机制强化，而退火后的Al2Ti1合金以细晶强化和析出强化为主。本工作充分证明了低成本fcc结构中熵合金的优化潜力，并促进了其在工业领域的应用。

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引用次数: 0

Mitigate the strength-ductility trade-off in high Cr content Ni2Cr2Fe MEA via heterogeneous structure design 通过非均质结构设计缓解高Cr含量Ni2Cr2Fe MEA的强度-延性权衡

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

Materials Science and Engineering: A

Pub Date : 2026-01-13 DOI: 10.1016/j.msea.2026.149783

Huaijin Wang , Bohua Yu , Ning Ding , Hongmei Chen , Jiayin Chen , Chi Zhang , Xinxin Yang , Zeyun Cai , Guoqiang Xie

High-entropy and medium-entropy alloys (HEAs/MEAs) with face-centered cubic (FCC) structures have attracted significant interest. However, their low strength limits their use in structural applications. Traditional strengthening methods often sacrifice ductility to improve strength. This issue is particularly severe in Co-free alloys with high Cr content, which tend to form brittle precipitates during heat treatment. This study aims to mitigate the strength-ductility trade-off in a Co-free Ni₂Cr₂Fe MEA through a heterogeneous grain structure. After cold rolling and short-term high-temperature annealing (950 °C, 2 min), the alloy exhibits a yield strength of 1009 MPa and a fracture elongation of 21 %, without second phase strengthening or complex alloying. The microstructure includes non-recrystallized regions (NRX) with high dislocation density and recrystallized regions (RX) with ultrafine grains. Dislocation strengthening in the NRX regions contributes mainly to the yield strength. The sub-structures in the deformed regions sustain plastic deformation and promote uniform strain distribution. These findings provide insights into improving the strength-ductility balance in high-Cr content alloys.

具有面心立方（FCC）结构的高熵和中熵合金（HEAs/MEAs）引起了人们的广泛关注。然而，它们的低强度限制了它们在结构应用中的使用。传统的加固方法往往牺牲延性来提高强度。这一问题在高Cr含量的无co合金中尤为严重，在热处理过程中容易形成脆性析出物。本研究旨在通过非均相晶粒结构缓解无co Ni2Cr2Fe MEA的强度-延性权衡。经冷轧和短期高温退火（950℃，2 min）后，合金的屈服强度为1009 MPa，断裂伸长率为21%，无第二相强化和复合合金化。显微组织包括位错密度高的非再结晶区（NRX）和超细晶粒的再结晶区（RX）。NRX区的位错强化主要对屈服强度有贡献。变形区的子结构维持塑性变形，促进均匀应变分布。这些发现为改善高铬合金的强度-塑性平衡提供了新的思路。

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引用次数: 0

Enhancing the interfacial strength of TiVNbTa refractory high entropy alloy joint for vacuum brazed via convex structure with nano-precipitates 采用带纳米析出物的凸形结构提高TiVNbTa耐火高熵合金真空钎焊接头的界面强度

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

Materials Science and Engineering: A

Pub Date : 2026-01-12 DOI: 10.1016/j.msea.2026.149779

Tingxiao Yu , Honglong Zhao , Qingdong Qin , Kai Feng , Juan Li , Chuang Yang , Yu Zeng

Achieving a high-quality joint in refractory high-entropy alloys (RHEAs) remains a significant challenge. In the present study, an appropriate filler metal of TiZrCuNi was selected to successfully join TiVNbTa RHEA using vacuum brazing. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and shear tests were used to systematically study the interfacial microstructure and mechanical properties of the joints. The results showed that the brazing seam consists of a diffusion-affected zone (Zone I) and a central brazed zone (Zone II), with a convex structure formed between these two zones. TEM images revealed α-Ti(Zr) nano-precipitates in Zone I. As the brazing temperature increased, the thickness of Zone I gradually increased, while the volume fraction of the blocky α-Ti phase in Zone II significantly decreased. The shear strength of the joints initially increased and then decreased with rising brazing temperature, reaching an optimal value of 179 ± 8 MPa after brazing at 880 °C for 15 min. The enhanced bonding strength of the joint is attributed to the interlocking effect of the convex structure and nano-precipitation strengthening. This study provides valuable insights into the welding challenges of TiVNbTa RHEA, offering guidance for achieving high-quality welding of RHEAs.

在难熔高熵合金（RHEAs）中实现高质量的接头仍然是一个重大挑战。本研究选择了一种合适的填充金属TiZrCuNi，用真空钎焊成功地连接了TiVNbTa RHEA。采用扫描电镜（SEM）、透射电镜（TEM）和剪切试验对接头的界面微观结构和力学性能进行了系统研究。结果表明：钎缝由扩散影响区（I区）和中心钎焊区（II区）组成，并在扩散影响区和中心钎焊区之间形成凸形结构；TEM图像显示α-Ti（Zr）纳米相在I区析出，随着钎焊温度的升高，I区厚度逐渐增大，而II区块状α-Ti相的体积分数显著降低。随着钎焊温度的升高，接头抗剪强度先升高后降低，在880℃钎焊15 min后达到最优值179±8 MPa。接头结合强度的提高主要是由于凹凸结构的联锁作用和纳米沉淀强化。本研究对TiVNbTa RHEA的焊接挑战提供了有价值的见解，为实现高质量的焊接提供了指导。

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引用次数: 0

The effects of various temperatures and stress levels on the microstructure and failure mechanism of Ti-43Al-9V-0.2Y alloy after creep 研究了不同温度和应力水平对Ti-43Al-9V-0.2Y合金蠕变后组织和破坏机制的影响

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

Materials Science and Engineering: A

Pub Date : 2026-01-12 DOI: 10.1016/j.msea.2026.149771

Yang-jie Gao, Hai-tao Jiang, Shi-wei Tian, Si-yuan Zhang, Chun-hui Wang, Yi Wu, Hui Zhang

This study presents an investigation into the tensile creep behavior of the Ti-43Al-9V-0.2Y alloy characterized by α₂/γ and β₀/γ lamellar microstructures, following heat treatment at various temperatures and under differing levels of applied stress. The study explores the intricate relationships among microstructural evolution, phase orientation rotation, interface energy, and failure mechanisms. The creep behavior of the alloy exhibits a pronounced temperature dependence, indicating the presence of distinct creep mechanisms at varying temperatures. During the creep process, the microstructural transformation is characterized by the decomposition of the lamellae and the α₂→γ phase transition. The rotation of the orientation relationship of β₀/γ lamellae from

< 110 >_{γ} / / < 111 >_{β_{0}}

to

< 110 >_{γ} / / < 100 >_{β_{0}}

leads to a significant increase in the interface energy of the new orientation relationship, which becomes a preferential site for defect generation. At 800 °C high temperature, although the dynamic recrystallization in the matrix of the β₀ phase alleviates stress concentration, the primary slip system of the γ phase is simultaneously altered to (111)//[101], resulting in the formation of the K-W pinning structure. Consequently, the plasticity of the sample deteriorates further.

本文研究了α2/γ和β0/γ片层组织的Ti-43Al-9V-0.2Y合金在不同温度和不同应力水平下的拉伸蠕变行为。该研究探讨了微观结构演化、相取向旋转、界面能和破坏机制之间的复杂关系。合金的蠕变行为表现出明显的温度依赖性，表明在不同温度下存在不同的蠕变机制。在蠕变过程中，微观组织转变以片层分解和α2→γ相变为特征。β0/γ片的取向关系由<；110>γ//<111>；β0向<；110>γ//<100>；β0的旋转导致新取向关系的界面能显著增加，成为缺陷生成的优先位点。在800℃高温下，虽然基体中β0相的动态再结晶缓解了应力集中，但γ相的初级滑移体系同时改变为(111)//[101]，导致K-W钉扎结构的形成。因此，试样的塑性进一步恶化。

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引用次数: 0

Tensile behaviour and microstructure of wire-based laser directed energy deposited normal- and high-strength steels 线基激光定向能沉积普通钢和高强钢的拉伸性能和显微组织

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

Materials Science and Engineering: A

Pub Date : 2026-01-12 DOI: 10.1016/j.msea.2026.149777

Fuming Yang , Si-Wei Liu , Ahmed Y. Elghazouli

Wire-based laser directed energy deposition, referred to as DED-LB or WLAM, is an emerging additive method using laser-melted wire feedstock, offering high deposition rate, smooth surfaces, and high precision. These capabilities indicate strong potential for construction, particularly for complex and optimised components, yet structural adoption necessitates in-depth assessments of mechanical and microstructural properties. This study describes a detailed experimental investigation into the mechanical behaviour and microstructural characteristics of ER70S-6 normal-strength and ER110S-G high-strength steels produced by DED-LB, with focus on property variability and orientation-induced anisotropy, compared with wire-based arc directed energy deposition (i.e., DED-Arc or WAAM). Tensile tests are performed on as-built specimens extracted from various orientations, with 3D scanning quantifying surface undulations, and digital image correlation recording full-field strains. The microstructures are characterised using optical and scanning electron microscopy and electron backscatter diffraction, and microhardness is mapped to microstructural phases. The results show that both steels show favourable stiffness properties and ductility with modest orientation-dependent anisotropy, where ultimate strength ratios across orientations are 0.95–1.00, and elongation ratios are 0.94–1.06. Most coefficients of variation for tensile strength and fracture elongation are found to be below 0.07, comparable to conventional steels. Dominant microstructural phases are shown to be uniformly distributed, with observed layer boundary regions in agreement with local microhardness. Relative to DED-Arc, DED-LB steels, especially for the high-strength grade, are shown to exhibit higher ductility with reduced orientation sensitivity while maintaining comparable strengths. Overall, the findings provide as-built dataset for informing wire-based process assessment and selection for civil engineering applications.

基于线材的激光定向能沉积，被称为d - lb或WLAM，是一种新兴的使用激光熔化线材原料的添加剂方法，具有沉积速率高、表面光滑和精度高的特点。这些能力表明了其在建筑方面的巨大潜力，特别是在复杂和优化组件方面，但结构的采用需要深入评估机械和微观结构特性。本研究详细研究了由d - lb生产的ER70S-6普通强度钢和ER110S-G高强度钢的力学行为和微观组织特征，重点研究了性能变化和取向诱导的各向异性，并与基于线的电弧定向能沉积（即d - arc或WAAM）进行了比较。拉伸试验对从不同方向提取的成品试样进行，3D扫描量化表面波动，数字图像相关记录全场应变。利用光学和扫描电子显微镜以及电子背散射衍射表征了显微结构，并将显微硬度映射到显微结构相。结果表明，两种钢均表现出良好的刚度和延性，且具有适度的取向相关各向异性，其中跨取向的极限强度比为0.95-1.00，延伸率为0.94-1.06。大多数抗拉强度和断裂伸长率的变化系数低于0.07，与传统钢相当。主要显微组织相分布均匀，观察到的层边界区域与局部显微硬度一致。相对于d - arc， d - lb钢，特别是高强度等级，表现出更高的延展性，取向敏感性降低，同时保持相当的强度。总体而言，研究结果为土木工程应用的基于线材的工艺评估和选择提供了建成数据集。

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引用次数: 0

Correlation between microstructural regulation and material properties: Effects of Zr content on mechanical and corrosion behaviors of CoCrFeNi high-entropy alloy 组织调控与材料性能的关系：Zr含量对CoCrFeNi高熵合金力学和腐蚀行为的影响

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

Materials Science and Engineering: A

Pub Date : 2026-01-11 DOI: 10.1016/j.msea.2026.149769

Peng Lyu , Lei Hao , Ken Deng , Shun Guo , Yu Liu , Xinlin Liu , Haixia Liu

In the present study, CoCrFeNiZr_x (x = 0.1, 0.3, 0.5, 1) high-entropy alloys (HEAs) were successfully fabricated using vacuum arc melting. The effects of Zr content on the microstructure, mechanical properties, wear resistance, and corrosion behavior were systematically examined. With increasing Zr content, the phase structure of the alloys progressively evolved from a face-centered cubic (FCC) + Laves phase assemblage to a Laves + body-centered cubic (BCC) phase assemblage. This evolution was accompanied by a corresponding microstructural transformation from a dendritic structure to eutectic and hypereutectic morphologies. Mechanical property characterization revealed that the addition of Zr significantly improved the hardness and strength of the alloys through the combined effects of solid-solution strengthening, second-phase strengthening, and interfacial strengthening. Among these alloys, the CoCrFeNiZr_0.3 alloy exhibited an optimal strength-plasticity balance. It showed yield and tensile strengths of 418 and 609 MPa, respectively, while retaining an elongation at break of 20.87 %. The CoCrFeNiZr₁ alloy achieved the highest hardness of 897.54 HV. However, its ductility decreased drastically. As Zr content increased, the wear mechanism transitioned from abrasive wear to oxidative wear, resulting in a marked improvement in wear resistance. Electrochemical measurements revealed that Zr addition was negatively correlated with the corrosion resistance of the alloys. Nevertheless, all compositions except CoCrFeNiZr₁ exhibited corrosion resistance superior to that of SS304 stainless steel. The present study clarified the mechanism by which Zr content modulated the microstructure of HEAs. As a result, a balance between optimized mechanical properties and corrosion resistance was achieved in these alloys.

本研究成功制备了CoCrFeNiZrx （x = 0.1, 0.3, 0.5, 1）高熵合金（HEAs）。研究了Zr含量对合金显微组织、力学性能、耐磨性和腐蚀性能的影响。随着Zr含量的增加，合金的相结构逐渐由面心立方(FCC) + Laves相组合演变为Laves +体心立方（BCC）相组合。这种演变伴随着相应的显微组织转变，从枝晶结构到共晶和过共晶形貌。力学性能表征表明，Zr的加入通过固溶强化、第二相强化和界面强化的综合作用，显著提高了合金的硬度和强度。其中CoCrFeNiZr0.3合金表现出最佳的强度塑性平衡。其屈服强度为418 MPa，抗拉强度为609 MPa，断裂伸长率为20.87%。CoCrFeNiZr1合金的最高硬度为897.54 HV。然而，其延展性急剧下降。随着Zr含量的增加，磨损机制由磨粒磨损转变为氧化磨损，耐磨性显著提高。电化学测量结果表明，Zr的加入与合金的耐蚀性呈负相关。然而，除CoCrFeNiZr1外，所有成分的耐腐蚀性都优于SS304不锈钢。本研究阐明了Zr含量对HEAs微观结构的调控机理。因此，在这些合金中实现了优化机械性能和耐腐蚀性之间的平衡。

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引用次数: 0

Overcoming property degradation in 6061-T6 aluminum alloy: Crack repair by friction stir processing and tailored heat treatments 克服6061-T6铝合金性能退化：用搅拌摩擦加工和定制热处理修复裂纹

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

Materials Science and Engineering: A

Pub Date : 2026-01-11 DOI: 10.1016/j.msea.2026.149774

Faisal Mustafa, Ahmed Hanafy Ibrahim, Basil M. Darras

Repairing cracks in high-strength aluminum alloys, such as AA6061-T6, is challenging due to the poor repair quality and mechanical property degradation (i.e., strength reduction) often experienced with conventional repair techniques (i.e., fusion-based). This study investigates the use of the solid-state friction stir processing (FSP) for crack repairing in 6061-T6 aluminum alloy, followed by two post-FSP heat treatments aimed at enhancing repair quality and restoring material strength. Mechanical properties, microstructure evolution, and crystallographic analyses demonstrated that FSP alone improved strength to 199.2 MPa (62.8 % recovery) and ductility to 24.8 %, though properties remained below the as-received condition due to dissolution of strengthening precipitates. Post-FSP artificial aging (FSP + Aged) increased strength to 221.1 MPa but reduced ductility to 14.3 %. The most effective route, FSP + Solutionized + Aged, achieved 293.7 MPa (92.7 % recovery) with a uniform precipitate distribution and near-complete hardness recovery, though ductility dropped to 9 %. Microstructural observations revealed fine equiaxed grains in the stir zone, while fracture analysis showed a transition from ductile to mixed brittle-ductile behavior, confirming a strength-ductility trade-off. These findings demonstrate that combining FSP with solutionizing and aging can restore near-original strength, but challenges remain in balancing ductility. The study highlights the importance of tailoring post-FSP heat treatments for effective structural repair of precipitation-hardened alloys.

修复高强度铝合金（如AA6061-T6）的裂纹是一项具有挑战性的工作，因为传统的修复技术（即基于熔合的修复技术）通常会出现修复质量差和机械性能下降（即强度降低）的问题。本研究研究了使用固态搅拌摩擦处理（FSP）修复6061-T6铝合金裂纹，然后进行两次FSP后热处理，旨在提高修复质量和恢复材料强度。力学性能、微观结构演变和晶体学分析表明，FSP单独将强度提高到199.2 MPa（恢复62.8%），塑性提高到24.8%，但由于强化沉淀的溶解，性能仍低于预期条件。FSP后人工时效（FSP +时效）使强度提高到221.1 MPa，但塑性降低到14.3%。最有效的方法是FSP +固溶+时效，可获得293.7 MPa（回收率92.7%），析出相分布均匀，硬度几乎完全恢复，但延展性下降到9%。显微组织观察显示搅拌区有细小的等轴晶粒，而断裂分析显示从延性到混合脆性-延性的转变，证实了强度-延性的权衡。这些研究结果表明，将FSP与固溶和时效相结合可以恢复接近原始的强度，但在平衡延性方面仍然存在挑战。该研究强调了定制fsp后热处理对有效修复析出硬化合金结构的重要性。

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引用次数: 0

Strong and deformable high-Al/Ti medium entropy alloy with good thermal stability via multiple coherent-precipitation 高al /Ti中熵合金，通过多相干析出具有良好的热稳定性

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

Materials Science and Engineering: A

Pub Date : 2026-01-10 DOI: 10.1016/j.msea.2026.149770

Donghui Wen , BeiBei Jiang , Tianlong Zhang , Mengqi Gao , Zhaowen Huang , Fengyu Kong , Yuanmin Zhu , Anding Wang , Qing Wang , Chain-Tsuan Liu

BCC-based high/medium-entropy alloys (H/MEAs) possess prominent high-temperature strength, low thermal expansion, and high thermal conductivity, making them a promising candidate for elevated-temperature applications. However, their limited deformability at room temperature (RT) hinders industrial implementation. Here, we report a novel cost-effective (FeCrNi)₈₅(AlTi)₁₅ MEA featuring a multiple-phase microstructure with BCC/L2₁, L2₁/BCC, and FCC/L1₂ coherent interfaces in the as-cast state. The strategic incorporation of L1₂-strengthened FCC matrix phase within brittle BCC and L2₁ matrices can activate hetero-deformation-induced (HDI) hardening effect, achieving an attractive compressive plasticity of 35 % at room temperature. The well-controlled L2₁-Ni₂AlTi, BCC, and L1₂-Ni₃(Al, Ti) nanoparticles coherently precipitate in BCC, L2_1, and FCC matrix phases, respectively, resulting in a super-high yield strength of 1850 MPa, outperforming existing B2/L2₁-strengthened BCC H/MEAs. The triple-coherent interface system demonstrates exceptional thermal stability, maintaining yield strengths of 850 MPa at 700 °C and 395 MPa at 800 °C. Moreover, this alloy exhibits a dynamic phase transformation-induced hardening effect during long-term aging due to the precipitation of σ-FeCr phase. These results provide a new strategy for overcoming the drawback of inadequate deformability in BCC-based alloys and developing novel advanced as-cast materials for high-temperature applications under compressive loading.

基于bcc的高/中熵合金（H/MEAs）具有突出的高温强度，低热膨胀和高导热性，使其成为高温应用的有希望的候选者。然而，它们在室温（RT）下有限的变形能力阻碍了工业应用。在这里，我们报道了一种新的具有成本效益的（FeCrNi）85(AlTi)15 MEA，其具有多相微观结构，具有BCC/L21， L21/BCC和FCC/L12的铸态共调界面。在脆性BCC和L21基体中加入l12强化的FCC基体相可以激活异质变形诱导（HDI）硬化效应，在室温下获得35%的抗压塑性。经过良好控制的L21- ni2alti、BCC和L12-Ni3（Al, Ti）纳米颗粒分别在BCC、L21和FCC基体相中均匀析出，获得了1850 MPa的超高屈服强度，优于现有的B2/L21强化BCC H/MEAs。三相干界面体系表现出优异的热稳定性，在700°C和800°C时分别保持850 MPa和395 MPa的屈服强度。长期时效过程中，由于析出了σ-FeCr相，合金表现出动态相变诱发的硬化效应。这些结果为克服bcc基合金变形能力不足的缺点以及开发用于高温压缩载荷下的新型先进铸态材料提供了新的策略。

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引用次数: 0