Materials Characterization最新文献_第3页

Effect of La2O3 content on TZM alloy tensile properties and strengthening-toughening mechanisms La2O3含量对TZM合金拉伸性能及强化增韧机理的影响

IF 5.5 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2026-02-06 DOI: 10.1016/j.matchar.2026.116132

Hui-Ling Yang , Yong Wei , Ling-Zi Tao , Lai-Ma Luo

Refractory molybdenum (Mo) alloys exhibit great potential for service in extreme environments. However, their poor room-temperature plasticity and strong tendency toward brittle fracture severely limit further engineering applications. As a representative engineering Mo alloy, the toughness of TZM still requires substantial improvement. In this study, spark plasma sintering (1900 °C) was employed to systematically investigate the effects of La₂O₃ additions (0, 0.5, and 1.0 wt%) on the microstructural evolution and mechanical properties of TZM alloy, with an emphasis on elucidating the underlying strengthening-toughening mechanisms. The results reveal that an appropriate La₂O₃ addition (0.5 wt%) markedly refines grains through the Zener pinning effect and promotes sintering densification, while simultaneously inducing the formation of second-phase particles composed of La₂O₃ cores surrounded by La-Ti-O composite structures. The TZM-0.5 wt% La₂O₃ alloy exhibits the most desirable strength-ductility synergy, characterized by an ultimate tensile strength of 642.5 MPa, an elongation of 28.9%, and a strength-ductility product of 18.6 GPa·%. Fractographic analysis shows a typical ductile fracture mode dominated by microvoid coalescence. In contrast, excessive La₂O₃ addition leads to particle coarsening and significantly deteriorated plasticity. Quantitative analysis indicates that grain refinement provides a strength increment of approximately 6.4 MPa estimated using the Hall Petch relationship, whereas Orowan strengthening contributes a strength increment of approximately 19 MPa. Together, these effects establish a coupled strengthening-toughening pathway based on grain refinement and intragranular dispersion strengthening. Within the investigated range, this work identifies 0.5 wt% La₂O₃ as the optimal doping level for TZM alloys and theoretical basis for achieving a synergistic enhancement of strength and ductility in Mo alloys.

难熔钼（Mo）合金在极端环境中表现出巨大的应用潜力。但其室温塑性差，脆性断裂倾向强，严重限制了其进一步的工程应用。作为工程Mo合金的代表，TZM的韧性仍有待大幅度提高。在本研究中，采用火花等离子烧结（1900°C）系统地研究了La2O3添加量（0、0.5和1.0 wt%）对TZM合金显微组织演变和力学性能的影响，重点阐明了潜在的强化-增韧机制。结果表明，适量添加La2O3 （0.5 wt%）通过齐纳钉钉效应使晶粒细化，促进烧结致密化，同时诱导形成由La2O3芯部包裹La-Ti-O复合结构组成的第二相颗粒。TZM-0.5 wt% La2O3合金表现出最理想的强度-塑性协同效应，其极限抗拉强度为642.5 MPa，伸长率为28.9%，强度-塑性系数为18.6 GPa·%。断口分析显示其断裂模式为典型的以微孔洞贯通为主的韧性断裂模式。相反，过量的La2O3添加会导致颗粒粗化，塑性显著恶化。定量分析表明，根据Hall - Petch关系估计，晶粒细化提供了约6.4 MPa的强度增量，而Orowan强化贡献了约19 MPa的强度增量。综上所述，这些效应建立了一个基于晶粒细化和晶内弥散强化的耦合强化-增韧途径。在研究范围内，本工作确定了0.5 wt% La2O3是TZM合金的最佳掺杂水平，这是实现Mo合金强度和延展性协同增强的理论基础。

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引用次数: 0

Additively manufactured CrCoNi/TiC composite exhibiting high strength and superior resistance to hydrogen embrittlement 增材制造的CrCoNi/TiC复合材料具有高强度和优异的抗氢脆性能

IF 5.5 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2026-02-06 DOI: 10.1016/j.matchar.2026.116133

Zhaosong Zhang , Shaohua Yan , Jinling Yang , Chengzhen Yin , Pengshuai Dai , Qinghua Qin

Although medium- and high-entropy alloys (M/HEAs) exhibit a certain degree of resistance to hydrogen embrittlement (HE), the effect of nanoceramic particle reinforcement on the HE behavior of high-strength MEA matrix composites remains insufficiently understood. In this study, we systematically investigate the HE response of a 2.2 wt% TiC nanoparticle-reinforced CrCoNi MEA matrix composite fabricated by laser powder bed fusion (LPBF), using cathodic electrochemical pre-charging at both room and cryogenic temperatures. At room temperature, the pre-charged composite shows good HE resistance, with a relative reduction of area (RRA) of 0.76 after 24 h of pre-charging. Notably, under the specific cryogenic slow strain rate tensile (SSRT) conditions employed in this study, hydrogen pre-charging is accompanied by an increase in tensile strength, while the RRA value (0.87) still suggests limited susceptibility to HE. The temperature-dependent HE behavior is discussed mainly in terms of hydrogen-enhanced localized plasticity (HELP) and hydrogen-enhanced decohesion (HEDE), with TiC nanoparticles playing a potential role in regulating hydrogen trapping and transport. At cryogenic temperature, reduced hydrogen mobility may suppress its redistribution during deformation, potentially weakening deformation localization associated with HELP. These results provide insights into the hydrogen-assisted deformation and damage behavior of high-strength MEA matrix composites and may support their potential application in hydrogen-containing environments.

虽然中、高熵合金（M/HEAs）表现出一定程度的抗氢脆（HE）能力，但纳米陶瓷颗粒增强对高强MEA基复合材料氢脆行为的影响尚不清楚。在这项研究中，我们系统地研究了激光粉末床熔融（LPBF）制备的2.2 wt% TiC纳米颗粒增强CrCoNi MEA基复合材料在室温和低温下的阴极电化学预充电的HE响应。室温下，预充后的复合材料表现出良好的抗HE性能，预充24 h后的相对面积减小（RRA）为0.76。值得注意的是，在本研究所采用的特定低温慢应变速率拉伸（SSRT）条件下，预充氢伴随着拉伸强度的增加，而RRA值（0.87）仍然表明HE敏感性有限。本文主要从氢增强局部塑性（HELP）和氢增强脱粘（HEDE）两个方面讨论了温度依赖的HE行为，TiC纳米颗粒在调节氢捕获和运输中发挥了潜在的作用。在低温下，氢迁移率的降低可能会抑制变形过程中的再分配，从而潜在地削弱与HELP相关的变形局部化。这些结果为高强度MEA基复合材料的氢辅助变形和损伤行为提供了见解，并可能支持其在含氢环境中的潜在应用。

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引用次数: 0

Synergetic effects of shot peening and nitrogen ion implantation on the fatigue behavior of TC17 titanium alloy 喷丸强化和氮离子注入对TC17钛合金疲劳行为的协同效应

IF 5.5 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2026-02-05 DOI: 10.1016/j.matchar.2026.116121

Chunling Xu , Wei Shao , Zhen Tan , Haili Yao , Xin Wang , Bo Yu , Zhihui Tang

TC17 titanium alloy is widely used in critical aero-engine components due to its excellent comprehensive properties. However, its susceptibility to high-cycle fatigue under severe service conditions necessitates effective surface enhancement techniques. This study investigates the synergistic effects of shot peening (SP) and nitrogen ion implantation (NII) on the fatigue behavior of TC17 alloy. SP significantly improves surface properties by introducing a refined grain layer, high dislocation density, and compressive residual stresses. NII further promotes the formation of TiN and Ti₂N nitride layers and facilitates the phase transformation from β to α and stress-induced α″ martensite. These microstructural changes contribute to a notable increase in surface hardness, residual compressive stress, which suppress surface crack initiation and retard crack propagation. The fatigue life of treated specimens is extended, demonstrating a direct correlation between microstructure refinement and fatigue performance enhancement.

TC17钛合金以其优异的综合性能被广泛应用于航空发动机的关键部件。然而，在恶劣的使用条件下，其对高周疲劳的敏感性需要有效的表面增强技术。研究了喷丸强化（SP）和氮离子注入（NII）对TC17合金疲劳性能的协同效应。SP通过引入细化的晶粒层、高位错密度和压缩残余应力显著改善了表面性能。NII进一步促进TiN和Ti2N氮化物层的形成，促进β向α相变和应力诱导α″马氏体的形成。这些微观组织的变化导致表面硬度和残余压应力的显著增加，从而抑制了表面裂纹的萌生，延缓了裂纹的扩展。处理后试样的疲劳寿命得到延长，表明微观组织细化与疲劳性能增强之间存在直接关系。

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引用次数: 0

The influence of oxide layer thickness on the microstructure and mechanical properties of the weld of MgLi alloy by friction stir welding 氧化层厚度对MgLi合金搅拌摩擦焊焊缝组织和力学性能的影响

IF 5.5 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2026-02-05 DOI: 10.1016/j.matchar.2026.116101

Yujie Chen , Xinze Dong , Xiaochun Ma , Zhiguo Lei , Yingxin Geng , Qingyu Shi , Mengran Zhou , Zhe Yu , Ruizhi Wu

MgLi alloys are prone to oxidation during thermal mechanical processing. The surface oxides undergo redistribution during FSW, significantly affecting the properties of alloys. The study investigated the influence of oxide layer thickness on weld formation, microstructure, mechanical properties, and corrosion resistance. The experimental results showed that the overly thick oxide film on the alloy surface was the main cause of the S-line formation in the weld area during friction stir welding. As the oxide layer thickness increased, the tensile strength of the welded joints remained relatively stable, whereas the elongation decreased significantly. Furthermore, with an increase in the amount of interfacial oxides, the corrosion resistance of the joints deteriorated rapidly. By adjusting the rotational speed to 400 rpm, the oxides were crushed and then evenly distributed, thereby suppressing the influence of the S line and defects on the elongation rate.

MgLi合金在热机械加工过程中容易氧化。在FSW过程中，表面氧化物发生重分布，显著影响合金的性能。研究了氧化层厚度对焊缝成形、显微组织、力学性能和耐蚀性的影响。实验结果表明，合金表面氧化膜过厚是搅拌摩擦焊焊缝区s线形成的主要原因。随着氧化层厚度的增加，焊接接头的抗拉强度保持相对稳定，伸长率明显下降。随着界面氧化物含量的增加，接头的耐蚀性迅速恶化。通过将转速调节到400 rpm，将氧化物粉碎后均匀分布，从而抑制S线和缺陷对延伸率的影响。

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引用次数: 0

Microstructure and friction and wear properties of WC/Fe matrix surface composites with different casting processes 不同铸造工艺WC/Fe基表面复合材料的组织与摩擦磨损性能

IF 5.5 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2026-02-04 DOI: 10.1016/j.matchar.2026.116120

Lin Yang , Fei Zhang , Zulai Li , Yifan Shi , Di Wu , Hanwei Fu , He Wei , Quan Shan

The present study investigates the microstructure and surface friction and wear mechanisms of WC/Fe matrix composites fabricated using three-dimensional preforms under different casting positions. Through the utilization of analytical techniques, including CT, SEM, and EBSD analyses of ceramic particle distribution and microstructure, in conjunction with finite element simulations of flow and stress field variations during casting, the interfacial strengthening mechanism of WC/Fe matrix composites is examined. This finding elucidates the correlation between casting position, microstructure, and friction and wear properties. The results indicate that ceramic particles undergo partial diffusion but remain predominantly distributed on the substrate surface, achieving surface strengthening. A broad interfacial reaction zone has been observed to form between the WC ceramic particles and the substrate, with the composite reaction zone primarily composed of Fe₆W₆C. Outside this interface layer, dislocation slip occurs in the Fe₆W₆C(

22 \bar{4}

)FCC phase, generating numerous dislocations that act as pinning sites. This mechanism serves to enhance the interface stability of the composite material. A comparative analysis was conducted, which revealed that the isostatic stress generated around the preform was minimal, thereby facilitating superior interfacial bonding. Friction and wear testing revealed that specimens prepared via the middle casting exhibited shallower wear scar depths, with an average depth of 2.342 μm.

研究了三维预成形WC/Fe基复合材料在不同铸造位置下的微观组织和表面摩擦磨损机理。利用CT、SEM和EBSD等分析技术对陶瓷颗粒分布和微观结构进行分析，结合铸造过程中流动和应力场变化的有限元模拟，研究了WC/Fe基复合材料的界面强化机制。这一发现阐明了铸造位置、显微组织和摩擦磨损性能之间的关系。结果表明：陶瓷颗粒经过部分扩散，但仍主要分布在基体表面，实现了表面强化；WC陶瓷颗粒与基体之间形成了广泛的界面反应区，复合反应区主要由Fe6W6C组成。在界面层外，位错滑移发生在Fe6W6C（224¯）FCC相，产生大量的位错作为钉住位点。这一机制有助于增强复合材料的界面稳定性。对比分析表明，预制体周围产生的等静应力最小，从而促进了良好的界面结合。摩擦磨损试验表明，中浇铸法制备试样的磨损疤痕深度较浅，平均深度为2.342 μm。

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引用次数: 0

Elevated temperature tensile and fracture behavior of Ti-6Al-4 V alloy fabricated by wire-based laser additive manufacturing: Microstructural evolution and deformation mechanism 线基激光增材制造ti - 6al - 4v合金的高温拉伸与断裂行为：显微组织演变与变形机制

IF 5.5 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2026-02-04 DOI: 10.1016/j.matchar.2026.116124

Jung-Hyun Park , Noh-Geon Song , Dae-Joong Kim , Kee-Ahn Lee

This study investigated the room and elevated-temperature tensile properties of Ti-6Al-4 V manufactured by wire laser additive manufacturing (WLAM) under various temperature conditions (room temperature, 300 °C, 500 °C, and 700 °C). Rapid cooling during processing produced α' martensite and α/β lamellar structures with strong crystallographic texture and high misorientation. This rapid β → α' transformation generated distinct variants and large inter-lath misorientation, producing lattice distortions. WLAM Ti-6Al-4 V exhibited a lower β-phase area percentage (1.7%) compared with the Wrought alloy (5.4%). These microstructural differences led to higher tensile strength than Wrought material at both room temperature and elevated temperatures. Fractography revealed micro-void formation, associated with elevated local misorientation within α' laths and along their interfaces. At room temperature, the α' martensite and fine α/β lamellar structures exhibited pronounced local misorientation near grain boundaries. At 300 ℃, 500 ℃, and 700 ℃, the WLAM alloy showed delayed activation of slip systems, primarily due to its α-lath structure. It maintained strength up to 500 °C owing to its pyramidal-leaning SF (basal: 0.333–0.360, prismatic: 0.226–0.247, pyramidal: 0.389–0.457), and limited CRSS reduction.

本文研究了线激光增材制造（WLAM）制备的ti - 6al - 4v在不同温度条件下（室温、300℃、500℃和700℃）的室温和高温拉伸性能。加工过程中快速冷却产生具有强晶体织构和高取向的α′马氏体和α/β片层结构。这种快速的β→α′转换产生了明显的变异体和大的板条间错位，产生了晶格畸变。WLAM ti - 6al - 4v的β相面积百分比（1.7%）低于锻造合金（5.4%）。这些微观结构差异导致在室温和高温下比变形材料具有更高的抗拉强度。断口形貌显示微孔洞的形成与α'板条内及其界面的局部定向错误升高有关。室温下，α′马氏体和细小的α/β片层组织在晶界附近表现出明显的局部取向错误。在300℃、500℃和700℃时，WLAM合金的α-板条结构导致滑移系统的延迟激活。由于其锥体倾斜SF（基面：0.333-0.360，棱柱面：0.226-0.247，锥体：0.389-0.457）和有限的CRSS降低，它在500°C下保持强度。

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引用次数: 0

Study on microwave absorption properties of “symmetrical pyramid-shaped” Fe3O4@Ti3C2Tx/graphite nanosheets composite materials “对称金字塔形”Fe3O4@Ti3C2Tx/石墨纳米片复合材料微波吸收性能研究

IF 5.5 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2026-02-04 DOI: 10.1016/j.matchar.2026.116125

Mengting Li , Yuanyuan Ma , Chengzhi Sun , Gengsu Zhu , Chunyu Wang , Bo Zhong , Long Xia

Two-dimensional transition metal carbides/nitrides, typically exemplified by Ti₃C₂T_x, featuring unique two-dimensional layered architectures, intrinsic defects, and abundant surface chemical compositions, have been recognized as highly promising novel microwave absorbing materials. Nevertheless, their intrinsic single dielectric loss mechanism significantly restricts the further improvement of microwave absorption performance. Herein, a facile solvothermal approach is proposed to anchor symmetrical pyramidal Fe₃O₄ onto the surfaces and interlayers of Ti₃C₂T_x and graphene nanoribbons, by which impedance matching is effectively balanced. The resulting composite, denoted as Fe₃O₄@Ti₃C₂T_x/GNs, is endowed with additional loss mechanisms, thereby enhancing its microwave absorption performance. At a Ti₃C₂T_x loading of 0.5 g/L and a thickness of 4.8 mm, the sample exhibits superior microwave absorption properties, with a minimum reflection loss of −51.97 dB achieved at 5.20 GHz, an effective absorption bandwidth of 2.72 GHz, and multi-band absorption characteristics. Notably, these findings provide valuable insights into the development of MXene-based composites with ultra-wide absorption bands and the clarification of electromagnetic wave absorption mechanisms.

以Ti3C2Tx为代表的二维过渡金属碳化物/氮化物具有独特的二维层状结构、固有缺陷和丰富的表面化学成分，是一种极具发展前景的新型微波吸收材料。然而，其固有的单一介质损耗机制严重制约了微波吸收性能的进一步提高。本文提出了一种简单的溶剂热方法，将对称的金字塔形Fe3O4锚定在Ti3C2Tx和石墨烯纳米带的表面和层间，从而有效地平衡阻抗匹配。所得到的复合材料（表示为Fe3O4@Ti3C2Tx/GNs）被赋予了额外的损耗机制，从而增强了其微波吸收性能。当Ti3C2Tx负载为0.5 g/L，厚度为4.8 mm时，样品表现出优异的微波吸收性能，在5.20 GHz处反射损耗最小为- 51.97 dB，有效吸收带宽为2.72 GHz，具有多波段吸收特性。值得注意的是，这些发现为开发具有超宽吸收带的mxene基复合材料和澄清电磁波吸收机制提供了有价值的见解。

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引用次数: 0

Investigation on nucleation and crystallographic structure evolution of dispersoids in Al-Mg-Mn-Si alloys Al-Mg-Mn-Si合金中分散体的形核及晶体结构演变研究

IF 5.5 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2026-02-03 DOI: 10.1016/j.matchar.2026.116102

Yu Liu , Yi Li , Zhen Li , Jian Qin , Bo Zhang , Hiromi Nagaumi

This study aims to elucidate the nucleation mechanism and the structural/phase evolution of dispersoids during the heating process in Al–Mg–Mn alloys with minor Si addition. The influence of 0.3wt.%Si on the precipitate characteristics of an Al-4.7wt.%Mg-0.8wt.%Mn-0.3wt.%Si alloy was investigated. Results indicate that Si addition accelerates the age-hardening response of the cast alloy. TEM observations confirm that microalloying with Si promotes the formation of Alₓ(Mn,Fe) and α-Al(Mn,Fe)Si precipitates with a higher number density, finer size, and more uniform distribution compared to the base alloy. This refinement is attributed to β' precursors, which serve as preferential nucleation sites, revealing an attached growth mechanism. Dispersoids formed under various heating conditions were identified. A structural transformation of Al₄(Mn,Fe) from a non-equilibrium quasicrystalline state to an equilibrium HCP structure was observed and analyzed. Furthermore, the crystallographic structures of other dispersoids under different heat treatment conditions were characterized.

本研究旨在阐明少量Si加入Al-Mg-Mn合金加热过程中分散体的形核机制和组织/相演变。0.3wt的影响。%Si对al -4.7wt、% mg -0.8wt、%Mn-0.3wt的析出特性的影响。研究了%Si合金。结果表明，Si的加入加速了铸合金的时效硬化反应。TEM观察证实，与基体合金相比，Si微合金化促进了Alₓ（Mn,Fe）和α-Al(Mn,Fe)Si相的形成，且α-Al(Mn,Fe)Si相的数量密度更高、尺寸更细、分布更均匀。这种细化归因于β′前体，它作为优先成核位点，揭示了附着的生长机制。鉴定了在不同加热条件下形成的分散体。观察并分析了硫酸铝（Mn,Fe）由非平衡准晶态向平衡HCP结构转变的过程。此外，还对不同热处理条件下其他分散体的晶体结构进行了表征。

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引用次数: 0

Enhancing strength while maintaining low elastic modulus in biomedical Ti-Zr-Nb medium-entropy alloys via aluminum-triggered stress-induced martensitic transformation 生物医学Ti-Zr-Nb中熵合金通过铝触发应力诱导马氏体相变增强强度，同时保持低弹性模量

IF 5.5 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2026-02-03 DOI: 10.1016/j.matchar.2026.116116

Shiwen Hu , Zefeng Chen , Pengjie Wei , Shaoyu Chai , Chen Xu , Dexue Liu

Recently, Ti-based multi-component body-centered cubic (BCC) medium- and high-entropy alloys (M/HEAs) have attracted considerable interest in the biomedical community, attributed to their outstanding specific strength, corrosion resistance, and wide compositional tunability. However, simultaneously achieving an ultra-low elastic modulus, excellent bio-mechanical compatibility, and adequate ductility remains a formidable challenge. In this study, a low-modulus Ti₄₅Zr₄₅Nb₁₀ medium-entropy alloy (MEA) was selected as a prototype. To further optimize its mechanical performance via phase stability tuning, Nb was partially substituted with Al, yielding a novel series of biomedical Ti₄₅Zr₄₅Nb_10-xAl_x (x = 0, 5, 7, at.%) MEAs. Results indicated that the gradual substitution of Al destabilized the β matrix, promoting the spontaneous formation of as-cast α" martensite. Upon plastic deformation, a hierarchical strengthening mechanism was activated, characterized by the stress-induced formation of orthorhombic α" bands alongside hexagonal α' phases. These phases preferentially nucleated perpendicular to the grain boundaries, often accompanied by α" precipitation. Mechanistically, the stress-induced α" transformation accommodated strain energy and delayed local necking, significantly elevating the ultimate tensile strength from 680 ± 12 MPa to 940 ± 22 MPa. Concurrently, the α' phases reinforced the matrix by impeding dislocation motion and retarding crack propagation, thus enhancing ductility. This synergy of strength and plasticity, driven by dynamic phase transformation mechanisms—specifically the energy dissipation via α" formation combined with α' precipitation strengthening—offers a novel strategy for tailoring martensitic transformation pathways. Furthermore, the elastic modulus of the alloys ranged from 45 ± 1.1 GPa to 61 ± 3 GPa，which could effectively reduce stress shielding. These findings provide valuable insights for the design of next-generation Ti-based M/HEAs featuring superior strength-ductility trade-offs and low elastic modulus.

近年来，ti基多组分体心立方（BCC）中高熵合金（M/HEAs）因其优异的比强度、耐腐蚀性和广泛的成分可调性而引起了生物医学界的极大兴趣。然而，同时实现超低弹性模量、优异的生物力学相容性和足够的延展性仍然是一个巨大的挑战。本研究选择低模量Ti45Zr45Nb10中熵合金（MEA）作为原型材料。为了通过相位稳定性调谐进一步优化其机械性能，将Nb部分替换为Al，得到一系列新型生物医用Ti45Zr45Nb10-xAlx （x = 0,5,7, at）。%)量。结果表明，Al的逐渐取代使β基体失稳，促进铸态α”马氏体的自发形成。在塑性变形时，激活了一个分层强化机制，其特征是应力诱导形成正交α”带和六方α”相。这些相优先在垂直于晶界的方向成核，常伴有α”析出。在力学上，应力诱导的α”相变容纳了应变能并延迟了局部颈缩，将极限抗拉强度从680±12 MPa显著提高到940±22 MPa。同时，α′相通过阻碍位错运动和延缓裂纹扩展来增强基体，从而提高了塑性。这种强度和塑性的协同作用，由动态相变机制驱动，特别是通过α‘形成结合α’沉淀强化的能量耗散，为定制马氏体转变途径提供了一种新的策略。合金的弹性模量在45±1.1 GPa ~ 61±3 GPa之间，可以有效降低应力屏蔽。这些发现为下一代ti基M/HEAs的设计提供了有价值的见解，该材料具有优越的强度-延性权衡和低弹性模量。

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引用次数: 0

Synchrotron X-ray diffraction analysis of 2D residual stress distribution in the brazed joint of PCBN ceramic and M42 steel PCBN陶瓷与M42钢钎焊接头中二维残余应力分布的同步加速器x射线衍射分析

IF 5.5 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2026-02-03 DOI: 10.1016/j.matchar.2026.116107

Lei Chen , Chun Li , Mushi Zheng , Bo Sun , Ruhao Zhou , Xiaoqing Si , Bo Yang , Haoran Yang , Jian Cao

Residual stress is a critical issue in ceramic/metal composite structure joints, yet reports on residual stresses in ceramic/phase-transforming metal joints remain scarce. In this study, the 2D residual stress distribution in a PCBN ceramic and M42 high-speed steel brazed joint is revealed for the first time using synchrotron XRD. The joint comprises a PCBN ceramic, a CuNi interlayer, and M42 steel. Notably, an abnormal residual stress distribution, with tensile stress present at both the surface and interface of the ceramic, is observed for the first time. The residual tensile stress near the ceramic interface exceeds 1000 MPa, and joint fracture occurs in the region of maximum tensile stress at the ceramic interface. Finite element analysis indicates that shrinkage of the CuNi layer dominates in joints formed below the phase transition temperature, resulting solely in residual compressive stress at the ceramic interface. In contrast, high-temperature XRD analysis and thermal expansion coefficient measurements confirm that the volume expansion caused by the phase transformation of M42 steel is a key factor contributing to the tensile stress at the ceramic interface.

残余应力是陶瓷/金属复合结构接头中的一个重要问题，但关于陶瓷/相变金属接头残余应力的研究报道很少。本文首次利用同步加速器x射线衍射仪（XRD）研究了PCBN陶瓷与M42高速钢钎焊接头的二维残余应力分布。接头由PCBN陶瓷、CuNi夹层和M42钢组成。值得注意的是，在陶瓷的表面和界面上首次观察到异常的残余应力分布，其中包括拉伸应力。陶瓷界面附近残余拉应力超过1000 MPa，接头断裂发生在陶瓷界面最大拉应力区域。有限元分析表明，在相变温度以下形成的接头中，CuNi层的收缩占主导地位，仅在陶瓷界面处产生残余压应力。高温XRD分析和热膨胀系数测量证实，M42钢相变引起的体积膨胀是导致陶瓷界面拉应力的关键因素。

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引用次数: 0