Journal of Materials Research and Technology-Jmr&t最新文献_第2页

Effect of specific pressure on the microstructure, tensile and tribological properties of semi-solid squeeze casting CuSn20P1 alloy 比压对半固态挤压铸造CuSn20P1合金组织、拉伸和摩擦学性能的影响

IF 6.6 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Materials Research and Technology-Jmr&t

Pub Date : 2026-03-01 Epub Date: 2025-12-05 DOI: 10.1016/j.jmrt.2025.12.020

Yongkun Li , Zhijie Wang , Hao Zhang , Rongfeng Zhou , Yingjie Sun

CuSn20P1 alloy was fabricated via semi-solid squeeze casting under various specific pressures (0–150 MPa). As the specific pressure increased gradually from 0 MPa to 150 MPa, the α-Cu dendrites disappeared and the grain size decreased. Meanwhile, higher specific pressure effectively alleviated the segregation of Sn, leading to a reduction in the amount of the δ-Cu₄₁Sn₁₁ phase and an increase in the content of β′-Cu_5.6Sn, which contributed to the improvement of mechanical properties. Calculation results indicated that Cu₃P, δ and β′ are all ductile stable phases with metallic characteristics and exhibit anisotropy. The order of hardness and Young's modulus values was consistently Cu₃P >δ >β′, which agreed reasonably well with the measured values within acceptable error margins. Mechanical property evaluations revealed that both the ultimate tensile strength (UTS) and elongation (EL) of the alloy reached their maximum values at 150 MPa, measuring 366.9 MPa and 0.52 %, respectively. These values represent improvements of 64.68 % and 156.16 % compared to those of the alloy prepared at 0 MPa. The alloy processed at 150 MPa also demonstrated the best wear resistance. As the specific pressure increased from 0 MPa to 150 MPa, the coefficient of friction (COF) and wear rate decreased from 0.483 to 2.01 × 10⁻⁴ mm³/N·m to 0.341 and 0.601 × 10⁻⁴ mm³/N·m, corresponding to reductions by factors of 1.42 and 3.34, respectively. Therefore, this study provides both an experimental basis and theoretical support for the design and application of high-Sn (Sn > 10 wt%) cast copper alloys with excellent mechanical properties.

在不同比压力（0 ~ 150 MPa）下，采用半固态挤压铸造法制备CuSn20P1合金。随着比压从0 MPa逐渐增大到150 MPa， α-Cu枝晶逐渐消失，晶粒尺寸减小。同时，较高的比压有效地缓解了Sn的偏析，导致δ-Cu41Sn11相的数量减少，β′-Cu5.6Sn的含量增加，从而改善了合金的力学性能。计算结果表明，Cu3P、δ和β′均为具有金属特征的延展性稳定相，并表现出各向异性。硬度和杨氏模量的顺序为Cu3P >；δ >β '，与实测值在可接受的误差范围内吻合较好。力学性能评价表明，合金的极限抗拉强度（UTS）和伸长率（EL）在150 MPa时均达到最大值，分别为366.9 MPa和0.52%。与在0 MPa下制备的合金相比，这两个数值分别提高了64.68%和156.16%。在150mpa下处理的合金也表现出最好的耐磨性。当比压从0 MPa增加到150 MPa时，摩擦系数（COF）和磨损率分别从0.483 ~ 2.01 × 10−4 mm3/N·m降低到0.341和0.601 × 10−4 mm3/N·m，分别降低1.42和3.34倍。因此，本研究为设计和应用具有优异力学性能的高锡（Sn > 10 wt%）铸铜合金提供了实验依据和理论支持。

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引用次数: 0

Multiscale defect engineering for synergistic strength, electrical and thermal conductivity in aluminum alloys: A review 铝合金协同强度、导电性和导热性的多尺度缺陷工程研究进展

IF 6.6 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Materials Research and Technology-Jmr&t

Pub Date : 2026-03-01 Epub Date: 2025-12-11 DOI: 10.1016/j.jmrt.2025.12.113

Wenjing Liu , Yuandong Li , Jin Qiu , Xiaomei Luo , Hongwei Zhou , Guangli Bi , Tijun Chen

Advanced aluminum alloys face an inherent trade-off between strength and electrical/thermal conductivities, creating a challenge for next-generation applications in electric vehicles (EVs) and aerospace. Moving beyond the traditional paradigm of defect elimination, this review presents a visionary roadmap for multiscale defect architectural design. This review synthesizes key strategies from the perspective of defect engineering, elucidating how zero-to three-dimensional defects fundamentally govern the competition between mechanical response and charge/heat transport. Crucially, this review establishes a framework for transitioning from passive defect control to active synergistic design, emphasizing strategies such as precipitate pinning, interface engineering, and gradient structures that strengthen the alloy while minimizing electron scattering. Finally, the review outlines a future trajectory driven by the convergence of multi-scale physics modeling, in-situ characterization, and machine learning. The objective is to establish a predictive capability that links atomic-scale defect configurations to macroscopic performance, providing a practicable pathway for determining the upper limits of synergistic strength-conductivity optimization.

先进铝合金面临着强度和导电性之间的内在权衡，这给下一代电动汽车和航空航天领域的应用带来了挑战。超越了传统的缺陷消除范例，这篇综述为多尺度缺陷架构设计提出了一个有远见的路线图。本文从缺陷工程的角度综合了关键策略，阐明了零到三维缺陷如何从根本上控制机械响应和电荷/热输运之间的竞争。重要的是，本文建立了一个从被动缺陷控制到主动协同设计的过渡框架，强调了诸如沉淀钉住、界面工程和梯度结构等策略，这些策略可以增强合金，同时最大限度地减少电子散射。最后，综述概述了由多尺度物理建模、原位表征和机器学习的融合驱动的未来轨迹。目标是建立一种将原子尺度缺陷构型与宏观性能联系起来的预测能力，为确定协同强度-电导率优化的上限提供切实可行的途径。

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引用次数: 0

Polyacrylonitrile nanofibers with hollow NiCu, Ni, and Cu nanospheres: Boosting electrocatalysis via enhanced interfacial charge transport and storage 含有空心NiCu、Ni和Cu纳米球的聚丙烯腈纳米纤维：通过增强界面电荷传输和存储来促进电催化

IF 6.6 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Materials Research and Technology-Jmr&t

Pub Date : 2026-03-01 Epub Date: 2025-12-03 DOI: 10.1016/j.jmrt.2025.12.030

Baran Sarac , Tolga Karazehir , Vladislav Zadorozhnyy , Dmitry Moskovskikh , Zhanna Yermekova , Selin Gümrükcü , Eray Yüce , A. Sezai Sarac

Multifunctional catalytic materials combining polymers with nanoparticles (NPs) lie in advancing their long-term stability, scalability, and predictable performance under real-world operating conditions. In this study, polyacrylonitrile (PAN) nanofibers loaded with hollow nickel (Ni), copper (Cu), and nickel–copper (NiCu) nanoparticles were fabricated. X-ray diffraction confirmed crystalline metal phases in the amorphous PAN matrix while indicating that ∼25 % of Cu as CuO. Spectroscopic analysis revealed alterations in the nitrile and aliphatic stretching bands resulting from NP incorporation. Cu/PAN exhibited a more than twofold increase in the –C–H to –CN bond area, attributed to oxygen-containing functional groups from CuO formation. UV–Vis spectra demonstrated tunable absorbance: NiCu/PAN exhibited the broadest and most intense absorption across 250–500 nm, reflecting strong plasmonic coupling between alloyed particles. Electron microscopy illustrated uniform dispersion of NPs on PAN surface, with all three nanofibers showing continuous and bead-free morphology, while NiCu composites displayed reduced NP agglomeration compared to monometallic counterparts. Electrochemical impedance spectroscopy in 0.1 M LiClO₄/ACN highlighted that NiCu/PAN possessed the lowest charge transfer resistance (R_ct ≈ 9.13 × 10² Ω cm²) and highest double-layer capacitance (C_dl ≈ 43.6 μF cm⁻²), surpassing Ni/PAN and Cu/PAN analogues. Furthermore, the smallest overpotential at 1 mA cm⁻² (−197 mV) and Tafel curve (∼286 mV dec⁻¹) were obtained for NiCu/PAN in 1 M KOH. The main objective of this research was to demonstrate that bimetallic interactions in hollow NiCu particles synergistically enhance interfacial charge transport and storage, thereby showing how metal composition and PAN nanofiber integration can optimize polymer-based nanocomposites for energy and environmental applications.

将聚合物与纳米颗粒（NPs）结合在一起的多功能催化材料的关键在于提高其在实际操作条件下的长期稳定性、可扩展性和可预测性。在本研究中，制备了负载中空镍（Ni）、铜（Cu）和镍铜（NiCu）纳米粒子的聚丙烯腈（PAN）纳米纤维。x射线衍射证实了非晶PAN基体中的结晶金属相，同时表明~ 25%的Cu为CuO。光谱分析显示，由于NP掺入，腈和脂肪族拉伸带发生了变化。Cu/PAN的-C-H到-CN键面积增加了两倍以上，这是由于CuO形成的含氧官能团。其中NiCu/PAN在250 ~ 500 nm范围内具有最宽、最强烈的吸收，反映了合金颗粒之间的强等离子体耦合。电镜观察显示，聚丙烯腈纳米纤维在PAN表面均匀分散，三种纳米纤维均呈现连续且无珠状形貌，而NiCu复合材料与单金属复合材料相比，聚丙烯腈纳米纤维的聚能减少。在0.1 M LiClO4/ACN中电化学阻抗谱显示，NiCu/PAN具有最低的电荷转移电阻（Rct≈9.13 × 102 Ω cm2）和最高的双层电容（Cdl≈43.6 μF cm−2），超过了Ni/PAN和Cu/PAN类似物。此外，在1 M KOH条件下，NiCu/PAN在1 mA cm−2处的过电位最小（- 197 mV）和Tafel曲线（~ 286 mV dec−1）。本研究的主要目的是证明空心NiCu颗粒中的双金属相互作用协同增强界面电荷传输和存储，从而展示金属成分和PAN纳米纤维的集成如何优化聚合物基纳米复合材料的能源和环境应用。

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引用次数: 0

The impact of scanning strategy on cell structures in PBF-LB/M/IN718: an in situ synchrotron x-ray diffraction study 扫描策略对PBF-LB/M/IN718细胞结构的影响：原位同步加速器x射线衍射研究

IF 6.6 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Materials Research and Technology-Jmr&t

Pub Date : 2026-03-01 Epub Date: 2025-11-27 DOI: 10.1016/j.jmrt.2025.11.214

B. Ferrari , A. Fantin , D. Said , A.N. Fitch , P. Suárez Ocano , T. Mishurova , I. Roveda , A. Kromm , R. Darvishi Kamachali , G. Bruno , A. Evans , G. Requena , L. Agudo Jácome , I. Serrano-Munoz

In additive manufacturing, any change of the process parameters, such as scanning strategy, directly affects the cooling rates, heat accumulation, and overall thermal history of the build. Consequently, parts built with different process parameters tend to have different levels of crystallographic texture, residual stress, and dislocation density. These features can influence the properties of the material and their development during post-processing operations. In this study, IN718 prisms were built by laser powder bed fusion (PBF-LB/M) using two different scanning strategies (continuous 67° rotations around the build direction, ROT, and alternating 0°/67° scans, ALT) to provide two different as-built conditions. In situ time-resolved synchrotron diffraction was performed during a solution heat treatment at 1027 °C for 1 h. Ex situ scanning electron microscopy was used to support and complement the in situ observations. An approach to quantify the effect of elemental microsegregation at the cell walls is developed based on the deconvolution of asymmetric γ-nickel matrix peaks. Following this approach, the scanning strategies are shown to affect the as-built fraction of cell walls in the material, resulting in a difference of approximately 5 %, in weight fraction, between ROT and ALT (19 % vs. 24 %, respectively). This microsegregation was observed to be rapidly homogenized during the heating ramp, and no significant changes to the peak shape in the γ peaks occurred during the isothermal part of the heat treatment, regardless of the scanning strategy.

在增材制造中，任何工艺参数的变化，如扫描策略，都会直接影响冷却速度、热量积累和整体热历史。因此，采用不同工艺参数制造的零件往往具有不同水平的晶体结构、残余应力和位错密度。这些特征会影响材料的性能及其在后处理操作中的发展。在本研究中，采用激光粉末床融合（PBF-LB/M）构建IN718棱镜，采用两种不同的扫描策略（围绕构建方向连续旋转67°，ROT和交替0°/67°扫描，ALT）提供两种不同的构建条件。在1027°C固溶热处理1小时期间进行原位时间分辨同步加速器衍射。非原位扫描电子显微镜用于支持和补充原位观察。基于不对称γ-镍基体峰的反褶积，提出了一种量化细胞壁上元素微偏析影响的方法。按照这种方法，扫描策略被证明会影响材料中细胞壁的建成部分，导致ROT和ALT之间的重量分数相差约5%（分别为19%和24%）。这种微偏析在加热斜坡过程中迅速均匀化，并且在热处理等温部分γ峰的峰形没有发生明显变化，无论扫描策略如何。

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引用次数: 0

Machine learning enabled prediction of high temperature mechanical behavior in additively manufactured AlSi9Cu3 alloy 机器学习能够预测增材制造AlSi9Cu3合金的高温力学行为

IF 6.6 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Materials Research and Technology-Jmr&t

Pub Date : 2026-03-01 Epub Date: 2025-12-10 DOI: 10.1016/j.jmrt.2025.12.088

Mohanraj Murugesan, Saurabh Gairola, Jayaganthan Rengaswamy, Palaniappan Ramu

Metal Additive Manufacturing (AM) offers significant opportunities for fabricating lightweight components with unique properties, but challenges remain in predicting the mechanical performance of alloys under elevated temperature and varying strain-rate conditions. The hot tensile behavior of additively manufactured AlSi9Cu3 alloy was systematically investigated using a Zwick-Roell Z100 universal testing machine, addressing a gap in the literature where no prior ML-based or experimental studies exist for this alloy at elevated temperature. Tests were performed from room temperature to 270 °C under 0.001 to 0.1 s⁻¹ strain rates, providing a comprehensive dataset for constitutive and Machine Learning (ML) modeling. Constitutive models, including the Johnson–Cook, modified Johnson–Cook, and modified Zerilli–Armstrong, were developed to describe the material’s thermomechanical response. While these models captured certain trends at specific conditions, their predictive capability was limited under strong thermal softening. To address these limitations, ML approaches were employed, with multi-layer perceptron and support vector regression models trained on the experimental data. These ML frameworks provided higher accuracy and generalization across both interpolation and extrapolation conditions, demonstrating their capability to overcome the limitations of constitutive formulations. Fractography revealed a transition from mixed-mode fracture with retained melt pool features at lower temperatures to ductile, recrystallization-assisted failure at elevated conditions. Overall, the integration of experimental testing, constitutive modeling, and ML-based prediction provides new insights into the deformation behavior of AM AlSi9Cu3 under hot tensile loading. The findings highlight the limitations of constitutive models and underscore the potential of ML for reliable, data-driven prediction of mechanical performance in metal AM.

金属增材制造（AM）为制造具有独特性能的轻质部件提供了重要机会，但在预测合金在高温和变应变率条件下的机械性能方面仍然存在挑战。使用zwickl - roell Z100万能试验机系统地研究了增材制造的AlSi9Cu3合金的热拉伸行为，解决了文献中没有基于ml的高温或实验研究的空白。在0.001至0.1 s−1应变速率下，从室温到270°C进行测试，为本构和机器学习（ML）建模提供了全面的数据集。本构模型包括Johnson-Cook模型、修正Johnson-Cook模型和修正zerili - armstrong模型，用于描述材料的热力学响应。虽然这些模型在特定条件下捕获了某些趋势，但在强热软化条件下，它们的预测能力有限。为了解决这些限制，采用了机器学习方法，在实验数据上训练了多层感知器和支持向量回归模型。这些机器学习框架在插值和外推条件下都提供了更高的准确性和泛化性，证明了它们克服本构公式限制的能力。断口形貌显示，在较低温度下，混合模式断裂保留了熔池特征，而在较高温度下，则发生了延展性再结晶辅助断裂的转变。总体而言，实验测试、本构建模和基于ml的预测相结合，为AM AlSi9Cu3在热拉伸载荷下的变形行为提供了新的见解。研究结果强调了本构模型的局限性，并强调了机器学习在金属增材制造中可靠的、数据驱动的机械性能预测方面的潜力。

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引用次数: 0

Role of nickel in tensile response and fracture of as-cast Al–5Cu-1.2Fe alloys: Intermetallic evolution analyzed by X-ray computed microtomography 镍在铸态Al-5Cu-1.2Fe合金拉伸响应和断裂中的作用：用x射线计算机显微断层扫描分析金属间演变

IF 6.6 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Materials Research and Technology-Jmr&t

Pub Date : 2026-03-01 Epub Date: 2025-12-11 DOI: 10.1016/j.jmrt.2025.12.110

Felipe Escher Saldanha , Jaderson Rodrigo da Silva Leal , Guilherme Lisboa de Gouveia , José Eduardo Spinelli

The presence of Fe-rich intermetallic compounds (IMCs) in recycled Al alloys often leads to coarse, brittle morphologies that degrade mechanical performance. Ni additions have been proposed to alter the formation and morphology of these phases, but their effects on tensile behavior and fracture mechanisms in Al–Cu–Fe alloys remain unclear, while three-dimensional (3D) characterization of IMCs is limited. This work investigates the influence of 1 wt% Ni on the solidification, microstructure, tensile properties, and fracture behavior of directionally solidified Al–5Cu–1.2Fe alloys. Al₁₃Fe₄ phase was identified in the ternary alloy, whereas Al₉FeNi formed in the Ni-containing alloy. At high cooling rates (∼13.0 ^oC/s), the ternary alloy exhibited higher tensile strength (>265 MPa) and elongation (>15 %) than the quaternary alloy (∼230 MPa, ∼9 %). Although Ni addition reduced the room-temperature properties compared with the ternary alloy, they remain high relative to conventional as-cast commercial Al–Cu based alloys, with the Al₉FeNi phase expected to provide benefits for thermal stability. Micro-CT revealed bulky, branched 3D Al₁₃Fe₄ networks in the ternary alloy, whereas Al₉FeNi particles in the quaternary alloy were partially refined but retained branched morphologies aligned with the solidification direction. Particle size distributions confirmed larger IMCs in the ternary alloy and more refined particles in the Ni-containing alloy at higher cooling rates, although coarse particles persisted at lower rates. Surface area-to-volume ratios were consistently higher in the ternary alloy, indicating more efficient stress transfer during loading compared to the quaternary alloy.

再生铝合金中富铁金属间化合物（IMCs）的存在通常会导致粗糙、脆性的形貌，从而降低机械性能。人们提出添加Ni可以改变这些相的形成和形态，但它们对Al-Cu-Fe合金的拉伸行为和断裂机制的影响尚不清楚，而IMCs的三维表征也很有限。本文研究了1wt % Ni对定向凝固Al-5Cu-1.2Fe合金凝固、显微组织、拉伸性能和断裂行为的影响。三元合金中存在Al13Fe4相，而含镍合金中存在Al9FeNi相。在高冷却速率（~ 13.0 oC/s）下，三元合金的抗拉强度（>265 MPa）和伸长率（> 15%）高于季系合金（~ 230 MPa, ~ 9%）。尽管与三元合金相比，Ni的加入降低了室温性能，但与传统铸态商用Al-Cu基合金相比，它们仍然很高，而Al9FeNi相有望提供热稳定性。显微ct显示，三元合金中Al13Fe4颗粒呈粗大的分支状三维网络，而第四系合金中的Al9FeNi颗粒部分细化，但仍保留了与凝固方向一致的分支状形貌。颗粒尺寸分布证实，在较高的冷却速率下，三元合金的imc较大，含镍合金的imc较细，尽管粗颗粒在较低的冷却速率下持续存在。三元合金的表面积体积比始终较高，这表明在加载过程中，与四元合金相比，应力传递更有效。

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引用次数: 0

High-speed helical milling for hole-making of Inconel 718 with ceramic endmills 用陶瓷立铣刀高速铣削Inconel 718制孔

IF 6.6 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Materials Research and Technology-Jmr&t

Pub Date : 2026-03-01 Epub Date: 2025-12-05 DOI: 10.1016/j.jmrt.2025.12.031

Robson Bruno Dutra Pereira , Gaizka Gómez Escudero , Amaia Calleja Ochoa , Haizea González Barrio , Pablo Fernández-Lucio , Cristian Fabian Pérez-Salinas , Lincoln Cardoso Brandão , Luis Norberto López de Lacalle

This paper investigates the high-speed helical milling of Inconel 718 with solid ceramic endmills. Tool life tests were performed. Flank wear of the frontal cutting edges was the main wear type. Temperatures in the range of Inconel 718 melting point were observed, giving some evidence of thermal softening of the alloy. Cutting forces were very high before the achievement of such temperature levels, justifying the premature tool wear. In the machined surfaces, it was observed adhered chips, plowing, and crushed burrs. Adhesion of Inconel 718 in the worn flank of the frontal cutting edges was the main wear mechanism. Diffusion was prominent with the highest cutting speed. A linear rise of temperature with wear, vc, and machined hole was observed. Despite the superior material removal, helical milling with ceramic endmills presented limited productivity considering the number of holes achieved.

研究了用实心陶瓷立铣刀高速铣削Inconel 718的工艺。进行了刀具寿命试验。正面切削刃的侧面磨损是主要的磨损类型。观察到的温度在Inconel 718熔点范围内，给出了合金热软化的一些证据。在达到这样的温度水平之前，切削力非常高，证明了过早的刀具磨损。在加工表面，观察到粘附的切屑、犁头和破碎的毛刺。因康乃尔718在切削刃磨损侧的粘附是主要的磨损机制。切削速度越快，扩散越明显。观察到温度随磨损、vc和加工孔呈线性上升。尽管具有优越的材料去除，但考虑到所获得的孔数，陶瓷立铣刀的螺旋铣削生产率有限。

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引用次数: 0

High-temperature tribological performance and wear mechanisms of GH90–K4169 superalloy friction pairs GH90-K4169高温合金摩擦副的高温摩擦学性能及磨损机理

IF 6.6 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Materials Research and Technology-Jmr&t

Pub Date : 2026-03-01 Epub Date: 2025-12-09 DOI: 10.1016/j.jmrt.2025.12.060

Junhao Han , Pengpeng Bai , Zhaojie Meng , Luo Yue , Xiangli Wen , Yu Tian

The rapid development of high-end equipment manufacturing has resulted in increasingly severe operating conditions for modern mechanical systems, creating higher demands for tribological reliability and thermal stability in friction-pair materials. Although K4169 and GH90 high-temperature alloys possess excellent intrinsic yield strength and creep resistance, their tribological behaviour under elevated temperatures remains insufficiently understood. In this work, the friction and wear characteristics of K4169–GH90 pairs were systematically evaluated through tribological testing and micromorphological analyses. The results show that temperature exerts a significant influence on their tribological performance. With increasing temperature, the wear rate of the K4169 disk decreases from 2.32 × 10⁻³ mm³/(N·m) to 0.65 × 10⁻³ mm³/(N·m), whereas the wear rate of the GH90 pin increases from 4.77 × 10⁻⁴ mm³/(N·m) to 2.95 × 10⁻⁴ mm³/(N·m). The superior hardness and toughness of GH90 promote the formation of loose oxidised debris and metal-transfer films on the K4169 surface at elevated temperatures. These adherent products progressively accumulate during sliding, roughening the disk surface. Oxidation on K4169 remains largely confined to adhesion zones and is less severe than that on GH90, resulting in a thinner oxide layer. As temperature rises, accelerated oxidation thickens the oxide layer and aggravates adhesive wear, generating additional adhered material. Overall, the K4169–GH90 friction pair demonstrates favourable high-temperature frictional behaviour, providing essential data and mechanistic insights for use in extreme thermal environments.

高端装备制造业的快速发展导致现代机械系统的工作条件越来越苛刻，对摩擦副材料的摩擦学可靠性和热稳定性提出了更高的要求。尽管K4169和GH90高温合金具有优异的内在屈服强度和抗蠕变性能，但它们在高温下的摩擦学行为仍未得到充分的了解。本文通过摩擦学测试和微观形貌分析，系统地评价了K4169-GH90副的摩擦磨损特性。结果表明，温度对其摩擦学性能有显著影响。随着温度的升高，K4169盘的磨损率从2.32 × 10−3 mm3/（N·m）下降到0.65 × 10−3 mm3/(N·m)，而GH90引脚的磨损率从4.77 × 10−4 mm3/（N·m）上升到2.95 × 10−4 mm3/（N·m）。高温下，GH90优异的硬度和韧性促进了K4169表面松散氧化碎屑和金属转移膜的形成。这些附着物在滑动过程中逐渐积累，使圆盘表面变得粗糙。与GH90相比，K4169的氧化主要局限于附着区，氧化程度较低，导致氧化层较薄。随着温度升高，加速氧化使氧化层变厚，加剧粘合剂磨损，产生额外的粘附材料。总的来说，K4169-GH90摩擦副表现出良好的高温摩擦性能，为极端热环境下的使用提供了必要的数据和机理见解。

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引用次数: 0

Micromechanical investigation of fracture behaviour in compacted graphite iron using the discrete element method 用离散元法对压实石墨铁断裂行为的微观力学研究

IF 6.6 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Materials Research and Technology-Jmr&t

Pub Date : 2026-03-01 Epub Date: 2025-12-05 DOI: 10.1016/j.jmrt.2025.12.047

Xiaoxuan Ding , Xingling Luo , Xiangqing Kong , Zewen Gu , Xiaonan Hou

Compacted graphite iron (CGI) is widely used in engineering applications due to its excellent mechanical properties, thermal conductivity, and wear resistance. However, its heterogeneous microstructure, which consists of worm-like graphite embedded within a ferritic-pearlitic matrix, presents significant challenges in accurately predicting fracture behaviour and damage evolution. To address this gap, we develop a micromechanical simulation framework based on the discrete element method (DEM) for the first systematic investigation of tensile deformation and fracture in CGI. The model incorporates image-based microstructural reconstruction and is quantitatively validated against experimental results in terms of stress–strain response and crack path morphology. Based on this validated model, a comprehensive parametric study is performed to evaluate the influence of graphite morphology and spatial distribution. The results reveal that increasing graphite volume fraction and misaligned orientations are the dominant factors reducing strength, while larger aspect ratios and particle sizes promote damage localization. Furthermore, under microstructural randomness, particle size remains a key factor affecting failure modes. These findings provide mechanistic insights into microstructure-sensitive fracture of CGI that are difficult to obtain experimentally, and demonstrate the potential of DEM as a predictive tool for understanding microstructure-sensitive failure and guiding the design of high-performance cast iron components.

压实石墨铁（CGI）因其优异的机械性能、导热性和耐磨性在工程中得到了广泛的应用。然而，它的非均匀微观结构（由嵌入铁素体-珠光体基体中的蠕虫状石墨组成）在准确预测断裂行为和损伤演变方面存在重大挑战。为了解决这一差距，我们开发了一个基于离散元法（DEM）的微力学模拟框架，首次系统地研究了CGI中的拉伸变形和断裂。该模型结合了基于图像的微观结构重建，并在应力应变响应和裂纹路径形态方面与实验结果进行了定量验证。在此基础上，对石墨形貌和空间分布的影响进行了综合参数研究。结果表明，石墨体积分数的增加和取向错位是降低强度的主要因素，而长径比和晶粒尺寸的增大促进了损伤局部化。此外，在微观结构随机性下，颗粒尺寸仍然是影响破坏模式的关键因素。这些发现提供了难以通过实验获得的CGI微结构敏感断裂的机理见解，并证明了DEM作为理解微结构敏感断裂和指导高性能铸铁部件设计的预测工具的潜力。

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引用次数: 0

Degradation of granulite and charnockite aggregates under simulated train loading: Morphological and mechanical insights for railway ballast 模拟列车荷载下麻粒岩和沙诺砾岩聚集体的降解：铁路道砟的形态和力学见解

IF 6.6 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Materials Research and Technology-Jmr&t

Pub Date : 2026-03-01 Epub Date: 2025-12-06 DOI: 10.1016/j.jmrt.2025.12.055

Jheyce de Souza Moreira Oliveira , Gustavo de Castro Xavier , Kelly de Oliveira Borges da Costa , Mariana Gomes Pinto Cherene , Rogério Pinto Ribeiro , Sergio Neves Monteiro , Afonso Rangel Garcez de Azevedo

The performance of railway ballast strongly depends on the mineralogical and morphological characteristics of the aggregates. However, little is known about the behavior of regional rocks in Rio de Janeiro, Brazil, under manipulation caused by railway traffic. This study investigates the manipulation of granulite and charnockite particles from the EF-118 railway line using Micro-Deval tests and the Aggregate Image Measurement System (AIMS II). Petrography, mercury intrusion porosimetry, and point load tests were also extended to correlate mineralogy, porosity, and mechanical strength with ballast performance. The results indicate that the Itaperuna granulite, with a higher biotite content and the presence of microcracks, showed greater mass loss (16.0 %) and lower uniaxial tensile strength (97 MPa). The Outeiro charnockite showed a significant reduction in angularity (≈36 %), affecting the interlocking of particles. In contrast, the Italva granulite showed better performance, with lower porosity (0.75 %), lower abrasion loss (14.9 %), and higher strength (110 MPa). Loss of angularity and texture alteration were identified as the main manipulation mechanisms, controlled by mineralogy and microstructural defects. The Weibull parameter (m) revealed greater homogeneity in Italva and greater variability in Itaperuna. Another important aspect is that a strong correlation was observed between the variation in angularity and porosity (R² = 1.00). This indicates that aggregates with higher porosity consistently undergo greater manipulation of angularity. The study provides new information on the suitability of local rocks for use as railway ballast, highlighting the Italva granulite as the most promising for long-term stability.

铁路道砟的性能在很大程度上取决于骨料的矿物学和形态特征。然而，人们对巴西里约热内卢里约热内卢地区岩石在铁路交通操纵下的行为知之甚少。本研究利用microdeval试验和综合图像测量系统（AIMS II）研究了EF-118铁路线麻粒岩和沙诺克岩颗粒的处理。岩石学、压汞孔隙度和点载荷测试也被扩展到将矿物学、孔隙度和机械强度与压载物性能相关联。结果表明：黑云母含量高且存在微裂纹的Itaperuna麻粒岩质量损失较大（16.0%），单轴抗拉强度较低（97 MPa）；Outeiro charnockite的角度明显降低（≈36%），影响了颗粒的联锁。相比之下，Italva麻粒岩表现出更好的性能，孔隙率低（0.75%），磨损损失低（14.9%），强度高（110 MPa）。棱角损失和织构变化是主要的操纵机制，受矿物学和显微组织缺陷的控制。威布尔参数(m)显示意大利种具有较大的同质性，而意大利种具有较大的变异性。另一个重要的方面是，在角度变化和孔隙度之间观察到很强的相关性（R2 = 1.00）。这表明具有较高孔隙度的聚集体始终经历更大的角度操纵。该研究为当地岩石作为铁路道砟的适用性提供了新的信息，突出了Italva麻粒岩最有希望长期稳定。

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引用次数: 0