Tribology International最新文献_第2页

High-entropy (MgCoNiCuZn)O5 ceramic coatings by sol-gel method: Tribological and protective properties over a wide temperature range 溶胶-凝胶法制备高熵（MgCoNiCuZn）O5陶瓷涂层：宽温度范围内的摩擦学和防护性能

IF 6.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

Tribology International

Pub Date : 2026-01-25 DOI: 10.1016/j.triboint.2026.111754

Xiaoxian Zhang , Yanping Wu , Yanjun Ma , Lei Chen , Hongxuan Li

Aerospace, energy, and automotive thermal-structural components urgently require protective coatings with wide-temperature wear resistance and scalable fabrication. High-entropy oxide (HEO) ceramic coatings are ideal for harsh environments, but existing fabrication process are energy-intensive and costly. Besides, systematic investigations on their temperature-dependent tribological and oxidation-resistant properties remain scarce. Herein, we developed a room temperature spraying sol-gel method to deposit (MgCoNiCuZn)O₅ HEO coatings on Inconel 718, achieving precise phase/microstructure control (single rock-salt structure, uniform element distribution, adhesion strength 33.26 MPa, surface roughness 271 nm). The core mechanism for exceptional wide-temperature wear resistance is a temperature-triggered reversible phase transition: secondary phases (CuO as lubricant, Co₂O₃ as wear-resistant phase) precipitate at 600–800 ℃ during friction, while re-dissolving into the matrix at 1000 ℃ to restore the single rock-salt phase. The minimum wear rate in 25–1000 ℃ is 0.37 × 10⁻⁵ mm³·N⁻¹·m⁻¹. Cyclic oxidation tests showed mild mass gain at 600–1000 ℃ (oxidation activation energy 139.7 kJ/mol, R²=0.9991) and wear rate ≤ 7.2 × 10⁻⁵ mm³·N⁻¹·m⁻¹ without catastrophic failures. High-temperature in-situ XRD and thermogravimetric analysis confirm excellent thermal stability. This study addresses HEO coatings’ low-temperature synthesis limitations, clarifies the temperature-dependent wear mechanism of (MgCoNiCuZn)O₅ coatings, and provides a viable engineering application approach.

航空航天、能源和汽车热结构部件迫切需要具有宽温度耐磨性和可扩展制造的保护涂层。高熵氧化物（HEO）陶瓷涂层是恶劣环境的理想选择，但现有的制造工艺是能源密集型和昂贵的。此外，对其温度相关的摩擦学和抗氧化性能的系统研究仍然很少。本文采用室温喷涂溶胶-凝胶法在Inconel 718表面沉积（MgCoNiCuZn）O5 HEO涂层，实现了相/微观结构的精确控制（单岩盐结构，元素分布均匀，附合力33.26 MPa，表面粗糙度271 nm）。超宽温耐磨性的核心机制是温度触发的可逆相变：在600 ~ 800℃摩擦时，二次相（CuO作为润滑剂，Co2O3作为耐磨相）析出，在1000℃时重新溶解到基体中，恢复为单一岩盐相。25 ~ 1000℃的最小磨损率为0.37 × 10−5 mm3·N−1·m−1。循环氧化试验表明，在600 ~ 1000℃条件下，氧化活化能139.7 kJ/mol, R2=0.9991，质量轻度增加，磨损率≤ 7.2 × 10−5 mm3·N−1·m−1，无灾难性失效。高温原位XRD和热重分析证实了优异的热稳定性。本研究解决了HEO涂层的低温合成局限性，阐明了（MgCoNiCuZn）O5涂层的温度依赖磨损机理，并提供了可行的工程应用途径。

{"title":"High-entropy (MgCoNiCuZn)O5 ceramic coatings by sol-gel method: Tribological and protective properties over a wide temperature range","authors":"Xiaoxian Zhang , Yanping Wu , Yanjun Ma , Lei Chen , Hongxuan Li","doi":"10.1016/j.triboint.2026.111754","DOIUrl":"10.1016/j.triboint.2026.111754","url":null,"abstract":"<div><div>Aerospace, energy, and automotive thermal-structural components urgently require protective coatings with wide-temperature wear resistance and scalable fabrication. High-entropy oxide (HEO) ceramic coatings are ideal for harsh environments, but existing fabrication process are energy-intensive and costly. Besides, systematic investigations on their temperature-dependent tribological and oxidation-resistant properties remain scarce. Herein, we developed a room temperature spraying sol-gel method to deposit (MgCoNiCuZn)O<sub>5</sub> HEO coatings on Inconel 718, achieving precise phase/microstructure control (single rock-salt structure, uniform element distribution, adhesion strength 33.26 MPa, surface roughness 271 nm). The core mechanism for exceptional wide-temperature wear resistance is a temperature-triggered reversible phase transition: secondary phases (CuO as lubricant, Co<sub>2</sub>O<sub>3</sub> as wear-resistant phase) precipitate at 600–800 ℃ during friction, while re-dissolving into the matrix at 1000 ℃ to restore the single rock-salt phase. The minimum wear rate in 25–1000 ℃ is 0.37 × 10<sup>−5</sup> mm<sup>3</sup>·N<sup>−1</sup>·m<sup>−1</sup>. Cyclic oxidation tests showed mild mass gain at 600–1000 ℃ (oxidation activation energy 139.7 kJ/mol, R<sup>2</sup>=0.9991) and wear rate ≤ 7.2 × 10<sup>−5</sup> mm<sup>3</sup>·N<sup>−1</sup>·m<sup>−1</sup> without catastrophic failures. High-temperature in-situ XRD and thermogravimetric analysis confirm excellent thermal stability. This study addresses HEO coatings’ low-temperature synthesis limitations, clarifies the temperature-dependent wear mechanism of (MgCoNiCuZn)O<sub>5</sub> coatings, and provides a viable engineering application approach.</div></div>","PeriodicalId":23238,"journal":{"name":"Tribology International","volume":"218 ","pages":"Article 111754"},"PeriodicalIF":6.1,"publicationDate":"2026-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Prediction of material removal profile in ultra-precision small tool polishing based on a hybrid mechanical–hydrodynamic removal mechanism 基于机械-流体动力混合去除机制的超精密小刀具抛光材料去除曲线预测

IF 6.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

Tribology International

Pub Date : 2026-01-23 DOI: 10.1016/j.triboint.2026.111747

Ning Kang , Shaohui Yin , Rong Li , Renchen Zhou , Xipeng Guo , Qiu Hong

Accurate prediction of the material removal profile (MRP) is crucial for achieving high-efficiency ultra-precision polishing of optical elements. This study proposes a hybrid mechanical–hydrodynamic removal mechanism that explicitly incorporates the material removal contribution of the polishing slurry into the ultra-precision small tool polishing process. Based on this mechanism, an MRP predictive model is developed by coupling the nonlinear elastic behavior of the polishing cloth with the shear-thinning behavior of the polishing slurry, and is experimentally validated under various polishing conditions. The predicted MRPs show non-uniform material removal with an elliptical-like shape, an asymmetric distribution along the X direction, and a Gaussian-like profile along the Y direction. These results agree well with experimental measurements, with an overall mean prediction error of 3.6 % across multiple indicators. The effects of polishing force and spindle speed on MRP are also examined. Increasing the polishing force from 1.5 N to 4.5 N and the spindle speed from 180 rpm to 720 rpm leads to notable increases in key MRP characteristics, including length, width, removal depth, and removal volume. This behavior arises because higher polishing force increases the contact pressure and expands the mechanical removal area, whereas higher spindle speed increases the relative velocity and the Preston coefficient and enlarges the hydrodynamic removal domain. This study provides accurate MRP prediction and improves understanding of material removal mechanisms in ultra-precision polishing processes.

准确预测材料去除轮廓（MRP）是实现光学元件高效超精密抛光的关键。本研究提出了一种机械-流体动力混合去除机制，明确地将抛光浆的材料去除贡献纳入超精密小工具抛光过程中。基于该机理，将抛光布的非线性弹性行为与抛光浆的剪切减薄行为耦合，建立了MRP预测模型，并在不同抛光条件下进行了实验验证。预测的mrp显示材料去除不均匀，呈椭圆形，沿X方向不对称分布，沿Y方向呈高斯分布。这些结果与实验测量结果吻合良好，多个指标的总体平均预测误差为3.6% %。研究了抛光力和主轴转速对MRP的影响。将抛光力从1.5 N增加到4.5 N，主轴转速从180 rpm增加到720 rpm，可以显著提高MRP的关键特性，包括长度、宽度、去除深度和去除体积。这是因为较高的抛光力增加了接触压力，扩大了机械去除面积，而较高的主轴转速增加了相对速度和普雷斯顿系数，扩大了流体动力去除范围。该研究提供了准确的MRP预测，并提高了对超精密抛光过程中材料去除机制的理解。

{"title":"Prediction of material removal profile in ultra-precision small tool polishing based on a hybrid mechanical–hydrodynamic removal mechanism","authors":"Ning Kang , Shaohui Yin , Rong Li , Renchen Zhou , Xipeng Guo , Qiu Hong","doi":"10.1016/j.triboint.2026.111747","DOIUrl":"10.1016/j.triboint.2026.111747","url":null,"abstract":"<div><div>Accurate prediction of the material removal profile (MRP) is crucial for achieving high-efficiency ultra-precision polishing of optical elements. This study proposes a hybrid mechanical–hydrodynamic removal mechanism that explicitly incorporates the material removal contribution of the polishing slurry into the ultra-precision small tool polishing process. Based on this mechanism, an MRP predictive model is developed by coupling the nonlinear elastic behavior of the polishing cloth with the shear-thinning behavior of the polishing slurry, and is experimentally validated under various polishing conditions. The predicted MRPs show non-uniform material removal with an elliptical-like shape, an asymmetric distribution along the <em>X</em> direction, and a Gaussian-like profile along the <em>Y</em> direction. These results agree well with experimental measurements, with an overall mean prediction error of 3.6 % across multiple indicators. The effects of polishing force and spindle speed on MRP are also examined. Increasing the polishing force from 1.5 N to 4.5 N and the spindle speed from 180 rpm to 720 rpm leads to notable increases in key MRP characteristics, including length, width, removal depth, and removal volume. This behavior arises because higher polishing force increases the contact pressure and expands the mechanical removal area, whereas higher spindle speed increases the relative velocity and the Preston coefficient and enlarges the hydrodynamic removal domain. This study provides accurate MRP prediction and improves understanding of material removal mechanisms in ultra-precision polishing processes.</div></div>","PeriodicalId":23238,"journal":{"name":"Tribology International","volume":"218 ","pages":"Article 111747"},"PeriodicalIF":6.1,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Atomic-scale simulations of nanoscratching behavior on copper coated with multilayer WSe2 多层WSe2涂层铜表面纳米划痕行为的原子尺度模拟

IF 6.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

Tribology International

Pub Date : 2026-01-23 DOI: 10.1016/j.triboint.2026.111753

Yongda Yan , Guangrui Zhao , Zihan Li , Yanquan Geng

WSe₂ exhibits excellent potential for reducing friction and resisting wear, making it suitable for application as a solid lubricant. In this study, the tribological properties of Cu coated with WSe₂ layers of varying thicknesses were investigated via nanoscale molecular dynamics simulations. Indentation tests were conducted on WSe₂-coated Cu with 0–3 layers to explore its mechanical response. Additionally, scratching processes at different indentation depths were performed, and the nanoscale friction morphology, mechanical response, defect propagation, and stress distribution were analyzed. The simulation results indicate that during the indentation process, the protective effect of WSe₂ coatings enhances with an increase in the number of layers. During scratching at small indentation depths, multilayer WSe₂ enables stick-slip friction to persist to a greater indentation depth as the number of WSe₂ layers increases. At relatively large scratching depths, an increase in the number of layers leads to initial fracture of the top atomic layer; due to stress release, the bottom WSe₂ layer undergoes rebound, which mitigates the impact of plastic damage on the Cu substrate. Furthermore, the failure mode of the topmost WSe₂ layer differs between monolayer and multilayer systems: in monolayer systems, WSe₂ mainly fails via zigzag-direction crack propagation and wrinkle formation; in multilayer systems, it tends to fracture into debris, as the interlayer interaction is stronger than that at the WSe₂/Cu interface. This work provides important theoretical support for the design of wear-resistant WSe₂ coatings, which are expected to be applied to small-scale components in micro/nanoelectromechanical systems (MEMS/NEMS).

WSe2在减少摩擦和抗磨损方面表现出优异的潜力，使其适合用作固体润滑剂。在本研究中，通过纳米尺度的分子动力学模拟研究了不同厚度的WSe2涂层Cu的摩擦学性能。对0-3层wse2包覆Cu进行压痕试验，探讨其力学响应。此外，在不同的压痕深度下进行了刮擦过程，并分析了纳米尺度的摩擦形貌、力学响应、缺陷扩展和应力分布。仿真结果表明，在压痕过程中，WSe2涂层的防护效果随着层数的增加而增强。在小压痕深度的刮擦过程中，随着WSe2层数的增加，多层WSe2使粘滑摩擦持续到更大的压痕深度。在较大的划痕深度下，层数的增加导致顶层原子层的初始断裂；由于应力释放，底部WSe2层发生回弹，减轻了塑性损伤对Cu衬底的影响。此外，单层和多层体系中最上层WSe2层的破坏模式不同：单层体系中，WSe2主要以之字形裂纹扩展和褶皱形成的方式破坏；在多层体系中，由于层间的相互作用比WSe2/Cu界面处的相互作用更强，它倾向于断裂成碎屑。该研究为WSe2耐磨涂层的设计提供了重要的理论支持，该涂层有望应用于微/纳米机电系统（MEMS/NEMS）的小尺寸部件。

{"title":"Atomic-scale simulations of nanoscratching behavior on copper coated with multilayer WSe2","authors":"Yongda Yan , Guangrui Zhao , Zihan Li , Yanquan Geng","doi":"10.1016/j.triboint.2026.111753","DOIUrl":"10.1016/j.triboint.2026.111753","url":null,"abstract":"<div><div>WSe<sub>2</sub> exhibits excellent potential for reducing friction and resisting wear, making it suitable for application as a solid lubricant. In this study, the tribological properties of Cu coated with WSe<sub>2</sub> layers of varying thicknesses were investigated via nanoscale molecular dynamics simulations. Indentation tests were conducted on WSe<sub>2</sub>-coated Cu with 0–3 layers to explore its mechanical response. Additionally, scratching processes at different indentation depths were performed, and the nanoscale friction morphology, mechanical response, defect propagation, and stress distribution were analyzed. The simulation results indicate that during the indentation process, the protective effect of WSe<sub>2</sub> coatings enhances with an increase in the number of layers. During scratching at small indentation depths, multilayer WSe<sub>2</sub> enables stick-slip friction to persist to a greater indentation depth as the number of WSe<sub>2</sub> layers increases. At relatively large scratching depths, an increase in the number of layers leads to initial fracture of the top atomic layer; due to stress release, the bottom WSe<sub>2</sub> layer undergoes rebound, which mitigates the impact of plastic damage on the Cu substrate. Furthermore, the failure mode of the topmost WSe<sub>2</sub> layer differs between monolayer and multilayer systems: in monolayer systems, WSe<sub>2</sub> mainly fails via zigzag-direction crack propagation and wrinkle formation; in multilayer systems, it tends to fracture into debris, as the interlayer interaction is stronger than that at the WSe<sub>2</sub>/Cu interface. This work provides important theoretical support for the design of wear-resistant WSe<sub>2</sub> coatings, which are expected to be applied to small-scale components in micro/nanoelectromechanical systems (MEMS/NEMS).</div></div>","PeriodicalId":23238,"journal":{"name":"Tribology International","volume":"218 ","pages":"Article 111753"},"PeriodicalIF":6.1,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

MoSi2-induced in-situ phase reinforcement in oscillating laser-directed energy deposited CoNiCrAlY coatings: Mechanism of enhanced high-temperature wear resistance 振荡激光定向能沉积CoNiCrAlY涂层中mosi2诱导原位相增强：增强高温耐磨性的机理

IF 6.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

Tribology International

Pub Date : 2026-01-23 DOI: 10.1016/j.triboint.2026.111745

Cheng Deng , Yuanlun Yang , Chunqiang Wang , Yongping Cai , Yunzhen Xu , Xinhua Wang , Zhenxin Zheng , Shengfeng Zhou

To enhance the high-temperature wear resistance of MCrAlY coatings, 10 wt% MoSi₂ particles were incorporated into a CoNiCrAlY coating via oscillating laser-directed energy deposition (OL-DED). The wear behavior of the coatings was systematically evaluated at room temperature, 500°C, and 900°C. Results indicate that the highly dynamic OL-DED molten pool promotes complete decomposition of MoSi₂, leading to uniform diffusion of Mo and Si and the in-situ formation of high-hardness (Cr, Mo)₃(Co, Ni)₅Si₂ and β phases uniformly dispersed within the γ-phase matrix. This microstructure provides synergistic wear resistance: the hard phases resist abrasion and plastic deformation, while the soft γ-phase absorbs strain energy. Increased hard-phase content also raises overall hardness, inhibiting subsurface deformation and preventing crack propagation in the protective oxide scale. Compared to the baseline CoNiCrAlY coating, the CoNiCrAlY-10MoSi₂ coating exhibits a lower friction coefficient and wear rate at all temperatures, with advantages becoming more pronounced at high temperatures. At 900°C, its average friction coefficient decreases significantly from 1.19 to 0.89, and the wear rate decreases from 0.62 × 10⁻⁴ mm³·N⁻¹·m⁻¹ to 0.48 × 10⁻⁴ mm³·N⁻¹·m⁻¹, a reduction of approximately 29.2 %.

为了提高MCrAlY涂层的高温耐磨性，通过振荡激光定向能沉积（OL-DED）将10个 wt%的MoSi2颗粒掺入CoNiCrAlY涂层中。在室温、500°C和900°C下系统地评估了涂层的磨损行为。结果表明：高动态OL-DED熔池促进MoSi2完全分解，Mo和Si均匀扩散，形成高硬度（Cr, Mo）3(Co, Ni)5Si2和β相，均匀分散在γ相基体内；这种微观结构提供了协同耐磨性：硬相抵抗磨损和塑性变形，而软γ相吸收应变能。增加的硬相含量也提高了整体硬度，抑制了地下变形，防止了保护氧化层中的裂纹扩展。与基线CoNiCrAlY涂层相比，CoNiCrAlY- 10mosi2涂层在所有温度下都具有更低的摩擦系数和磨损率，并且在高温下优势更加明显。在900℃时，其平均摩擦系数从1.19显著降低到0.89，磨损率从0.62 × 10−4 mm3·N−1·m−1降低到0.48 × 10−4 mm3·N−1·m−1，降低幅度约为29.2 %。

{"title":"MoSi2-induced in-situ phase reinforcement in oscillating laser-directed energy deposited CoNiCrAlY coatings: Mechanism of enhanced high-temperature wear resistance","authors":"Cheng Deng , Yuanlun Yang , Chunqiang Wang , Yongping Cai , Yunzhen Xu , Xinhua Wang , Zhenxin Zheng , Shengfeng Zhou","doi":"10.1016/j.triboint.2026.111745","DOIUrl":"10.1016/j.triboint.2026.111745","url":null,"abstract":"<div><div>To enhance the high-temperature wear resistance of MCrAlY coatings, 10 wt% MoSi<sub>2</sub> particles were incorporated into a CoNiCrAlY coating via oscillating laser-directed energy deposition (OL-DED). The wear behavior of the coatings was systematically evaluated at room temperature, 500°C, and 900°C. Results indicate that the highly dynamic OL-DED molten pool promotes complete decomposition of MoSi<sub>2</sub>, leading to uniform diffusion of Mo and Si and the in-situ formation of high-hardness (Cr, Mo)<sub>3</sub>(Co, Ni)<sub>5</sub>Si<sub>2</sub> and β phases uniformly dispersed within the γ-phase matrix. This microstructure provides synergistic wear resistance: the hard phases resist abrasion and plastic deformation, while the soft γ-phase absorbs strain energy. Increased hard-phase content also raises overall hardness, inhibiting subsurface deformation and preventing crack propagation in the protective oxide scale. Compared to the baseline CoNiCrAlY coating, the CoNiCrAlY-10MoSi<sub>2</sub> coating exhibits a lower friction coefficient and wear rate at all temperatures, with advantages becoming more pronounced at high temperatures. At 900°C, its average friction coefficient decreases significantly from 1.19 to 0.89, and the wear rate decreases from 0.62 × 10<sup>−4</sup> mm<sup>3</sup>·N<sup>−1</sup>·m<sup>−1</sup> to 0.48 × 10<sup>−4</sup> mm<sup>3</sup>·N<sup>−1</sup>·m<sup>−1</sup>, a reduction of approximately 29.2 %.</div></div>","PeriodicalId":23238,"journal":{"name":"Tribology International","volume":"218 ","pages":"Article 111745"},"PeriodicalIF":6.1,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Improved high-temperature tribological properties in Cr2AlC MAX films via friction-induced glaze layer formation 通过摩擦诱导釉层形成改善Cr2AlC MAX薄膜的高温摩擦学性能

IF 6.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

Tribology International

Pub Date : 2026-01-23 DOI: 10.1016/j.triboint.2026.111742

Bingsen Jia , Xiaowei Tang , Wenju Xu , Xinyu Jiang , Xiaohong Liu , Li Ji , Kunjie Wang , Hongxuan Li

Owing to their unique layered hexagonal crystal structure and hybrid metallic-covalent bonding characteristics, Cr₂AlC MAX-phase ceramics exhibit outstanding thermal conductivity, oxidation resistance, and thermal stability at elevated temperatures. These properties render them highly sought after for tribological systems operating in extreme environments. This work investigates the dry sliding tribological behaviour of Cr₂AlC films in air between 700 and 900 ℃, examining the temperature-dependent evolution of their friction and wear characteristics, as well as the corresponding oxidation protection mechanisms. Results indicate that the coefficient of friction decreases progressively with increasing temperature, while the wear rate exhibits a non-monotonic trend, initially increasing followed by a reduction. At 900 ℃, the wear rate diminishes significantly to 1.2 × 10⁻⁵ mm³/(N·m), demonstrating exceptional high-temperature lubrication performance. This superior performance is primarily attributed to the in situ formation of a continuous, dense Cr₂O₃-Al₂O₃ composite oxide film on the friction contact surface. This oxide film not only enhances the material's shear resistance but also effectively isolates direct contact between the mating surfaces, thereby transforming the wear mechanism from abrasive wear-dominated to oxide film lubrication-dominated. Furthermore, in high-temperature oxidation experiments, the selective outward diffusion of Al serves as the key driver for the formation of the protective Al₂O₃ layer. As temperatures rise further, Cr tends to precipitate at Al₂O₃ grain boundaries or defect sites, effectively filling microscopic diffusion channels within the oxide layer and enhancing structural integrity. This research provides new insights for the design and application of MAX phase ceramics in high-temperature friction systems.

由于其独特的层状六方晶体结构和杂化金属共价键特性，Cr2AlC max相陶瓷在高温下表现出优异的导热性、抗氧化性和热稳定性。这些特性使其在极端环境下的摩擦学系统中备受追捧。本研究研究了Cr2AlC薄膜在700 - 900℃空气中的干滑动摩擦学行为，研究了其摩擦磨损特性的温度依赖演变，以及相应的氧化保护机制。结果表明：摩擦系数随温度升高而逐渐减小，磨损率呈现先增大后减小的非单调趋势；在900℃时，磨损率显著降低至1.2 × 10−5 mm3/(N·m)，表现出优异的高温润滑性能。这种优异的性能主要归功于在摩擦接触面上原位形成连续致密的Cr2O3-Al2O3复合氧化膜。这种氧化膜不仅提高了材料的抗剪切能力，而且有效地隔离了配合面之间的直接接触，从而使磨损机制从磨料磨损为主转变为氧化膜润滑为主。此外，在高温氧化实验中，Al的选择性向外扩散是Al2O3保护层形成的关键驱动因素。随着温度的升高，Cr倾向于在Al₂O₃晶界或缺陷部位析出，有效地填充了氧化层内部的微观扩散通道，增强了结构的完整性。该研究为MAX相陶瓷在高温摩擦系统中的设计和应用提供了新的思路。

{"title":"Improved high-temperature tribological properties in Cr2AlC MAX films via friction-induced glaze layer formation","authors":"Bingsen Jia , Xiaowei Tang , Wenju Xu , Xinyu Jiang , Xiaohong Liu , Li Ji , Kunjie Wang , Hongxuan Li","doi":"10.1016/j.triboint.2026.111742","DOIUrl":"10.1016/j.triboint.2026.111742","url":null,"abstract":"<div><div>Owing to their unique layered hexagonal crystal structure and hybrid metallic-covalent bonding characteristics, Cr<sub>2</sub>AlC MAX-phase ceramics exhibit outstanding thermal conductivity, oxidation resistance, and thermal stability at elevated temperatures. These properties render them highly sought after for tribological systems operating in extreme environments. This work investigates the dry sliding tribological behaviour of Cr<sub>2</sub>AlC films in air between 700 and 900 ℃, examining the temperature-dependent evolution of their friction and wear characteristics, as well as the corresponding oxidation protection mechanisms. Results indicate that the coefficient of friction decreases progressively with increasing temperature, while the wear rate exhibits a non-monotonic trend, initially increasing followed by a reduction. At 900 ℃, the wear rate diminishes significantly to 1.2 × 10<sup>−5</sup> mm<sup>3</sup>/(N·m), demonstrating exceptional high-temperature lubrication performance. This superior performance is primarily attributed to the in situ formation of a continuous, dense Cr<sub>2</sub>O<sub>3</sub>-Al<sub>2</sub>O<sub>3</sub> composite oxide film on the friction contact surface. This oxide film not only enhances the material's shear resistance but also effectively isolates direct contact between the mating surfaces, thereby transforming the wear mechanism from abrasive wear-dominated to oxide film lubrication-dominated. Furthermore, in high-temperature oxidation experiments, the selective outward diffusion of Al serves as the key driver for the formation of the protective Al<sub>2</sub>O<sub>3</sub> layer. As temperatures rise further, Cr tends to precipitate at Al₂O₃ grain boundaries or defect sites, effectively filling microscopic diffusion channels within the oxide layer and enhancing structural integrity. This research provides new insights for the design and application of MAX phase ceramics in high-temperature friction systems.</div></div>","PeriodicalId":23238,"journal":{"name":"Tribology International","volume":"218 ","pages":"Article 111742"},"PeriodicalIF":6.1,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of morphology on friction anisotropy of GLAD Mo films 形貌对GLAD Mo薄膜摩擦各向异性的影响

IF 6.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

Tribology International

Pub Date : 2026-01-23 DOI: 10.1016/j.triboint.2026.111721

Guilherme B. Rodrigues , Pascal Boulet , Nicolas Martin , Fabien Amiot , Guillaume Colas

Frictional behavior of molybdenum thin films deposited by Glancing Angle Deposition (GLAD) was investigated at various deposition angles (

α

) using single-scratch tests under different loads and directions. Films deposited at

α \geq 5 0^{\circ}

developed elliptical columnar structures, resulting in orthotropic anisotropy due to direction-dependent plastic deformation. Increasing the deposition angle enhanced intercolumnar porosity, thereby reducing both friction and anisotropy. Conversely, the film deposited at

α = 4 0^{\circ}

exhibited strong anisotropy and a non-Coulombic frictional response. Moreover, this film showed non-centrosymmetric behavior, requiring a non-linear model to accurately describe its frictional anisotropy.

采用单划痕试验研究了不同沉积角（α）下掠角沉积钼薄膜在不同载荷和方向下的摩擦行为。在α≥50°处沉积的薄膜形成椭圆柱状结构，由于方向相关的塑性变形而导致正交各向异性。增大沉积角度可提高柱间孔隙度，从而降低摩擦和各向异性。相反，在α=40°处沉积的薄膜表现出强烈的各向异性和非库仑摩擦响应。此外，该薄膜表现出非中心对称的行为，需要非线性模型来准确描述其摩擦各向异性。

引用次数: 0

Fractal tangential stiffness model of the joint surface considering stick–slip characteristics at asperity interfaces 考虑粗糙界面粘滑特性的节理面分形切向刚度模型

IF 6.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

Tribology International

Pub Date : 2026-01-23 DOI: 10.1016/j.triboint.2026.111743

Hui Xiao , Yongsheng Zhao , Ying Li , Lele Liu , He Ma , Qiang Cheng , Zhifeng Liu

In high-end CNC equipment systems, the tangential stiffness of bolted joint surfaces is a key mechanical parameter governing assembly performance and dynamic stability. To address the limitation of conventional models in describing partial slip behavior at contact interfaces, this study proposes a tangential stiffness model for joint surfaces by analyzing the coupled evolution mechanism of adhesion and slip regions of asperities. First, based on the evolution of interfacial slip, a slip ratio is introduced as a key state parameter, and fractal tangential stiffness models for a single asperity and for the joint surface are established. By coupling the asperity size effect with the slip ratio, the multiscale deformation modes of the joint surface are revealed. On this basis, the influences of relevant parameters on tangential stiffness are systematically investigated. The results show that the tangential stiffness varies nonlinearly with the fractal dimension

D

and the slip ratio

s

, reaching a peak at approximately

D = 2.5

, and exhibiting fluctuations with changes in the fractal roughness

G

. An increase in the slip ratio effectively enhances the tangential stiffness, and this enhancement becomes more pronounced with increasing

D

. Finally, an experimental setup is established and comparisons with conventional models are performed, verifying the accuracy and applicability of the proposed model. The results provide theoretical support for contact performance analysis and assembly optimization of mechanical joint surfaces.

在高端数控设备系统中，螺栓连接面切向刚度是控制装配性能和动态稳定性的关键力学参数。为了解决传统模型在描述接触界面部分滑移行为方面的局限性，本研究通过分析接合面黏附区和滑移区耦合演化机制，提出了一种面向接合面的切向刚度模型。首先，基于界面滑移的演化规律，引入滑移率作为关键状态参数，建立了单个粗糙面和节理面的分形切向刚度模型；通过将粗糙体尺寸效应与滑移率耦合，揭示了节理面的多尺度变形模式。在此基础上，系统研究了相关参数对切向刚度的影响。结果表明，切向刚度随分形维数D和滑移比s呈非线性变化，在D=2.5左右达到峰值，并随分形粗糙度g的变化而波动。增大滑移比可有效增强切向刚度，且随着D的增大增强更为明显。验证所提出模型的准确性和适用性。研究结果为机械结合面接触性能分析和装配优化提供了理论支持。

{"title":"Fractal tangential stiffness model of the joint surface considering stick–slip characteristics at asperity interfaces","authors":"Hui Xiao , Yongsheng Zhao , Ying Li , Lele Liu , He Ma , Qiang Cheng , Zhifeng Liu","doi":"10.1016/j.triboint.2026.111743","DOIUrl":"10.1016/j.triboint.2026.111743","url":null,"abstract":"<div><div>In high-end CNC equipment systems, the tangential stiffness of bolted joint surfaces is a key mechanical parameter governing assembly performance and dynamic stability. To address the limitation of conventional models in describing partial slip behavior at contact interfaces, this study proposes a tangential stiffness model for joint surfaces by analyzing the coupled evolution mechanism of adhesion and slip regions of asperities. First, based on the evolution of interfacial slip, a slip ratio is introduced as a key state parameter, and fractal tangential stiffness models for a single asperity and for the joint surface are established. By coupling the asperity size effect with the slip ratio, the multiscale deformation modes of the joint surface are revealed. On this basis, the influences of relevant parameters on tangential stiffness are systematically investigated. The results show that the tangential stiffness varies nonlinearly with the fractal dimension <span><math><mi>D</mi></math></span> and the slip ratio <span><math><mi>s</mi></math></span>, reaching a peak at approximately <span><math><mrow><mi>D</mi><mo>=</mo><mn>2.5</mn></mrow></math></span>, and exhibiting fluctuations with changes in the fractal roughness <span><math><mi>G</mi></math></span>. An increase in the slip ratio effectively enhances the tangential stiffness, and this enhancement becomes more pronounced with increasing <span><math><mi>D</mi></math></span>. Finally, an experimental setup is established and comparisons with conventional models are performed, verifying the accuracy and applicability of the proposed model. The results provide theoretical support for contact performance analysis and assembly optimization of mechanical joint surfaces.</div></div>","PeriodicalId":23238,"journal":{"name":"Tribology International","volume":"218 ","pages":"Article 111743"},"PeriodicalIF":6.1,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Self-reactive lubricating graphite-like coating for low-friction hydraulic energy converters 低摩擦液压能量转换器用自反应润滑类石墨涂层

IF 6.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

Tribology International

Pub Date : 2026-01-23 DOI: 10.1016/j.triboint.2026.111749

Xiaolong Zhang , Kaiming Zheng , Junhui Zhang , Jianxiong Wu , Hongbin Lin , Xiaojiang Lu , Bing Xu , Chao Zhang

Hydraulic energy converters are components that can realize the conversion between mechanical energy and hydraulic energy. Their powers can be as high as 2 × 10⁶ W or more. For a high-power component, even if its efficiency is increased by 1 %, it will bring huge energy savings. However, current research mainly focuses on improving the efficiency of high-speed hydraulic energy converters via enhancing hydrodynamic effect, with little attention paid to low-speed hydraulic energy converters (<500 r/min). For that, this study develops a self-reactive lubricating graphite-like coating specifically for hydraulic energy converters to reduce mechanical friction that leads to low efficiency at low speeds. The self-reactive lubricating graphite-like coating is composed of two elements: carbon and tungsten. The results of the ring-block tests show that the coating with an atomic ratio (carbon: tungsten) of 0.51:0.49 has lower friction and temperature rise under three load conditions. Its mechanism is that an appropriate content of tungsten can react with additives in hydraulic oil to form a lubricating film, such as WS₂ and PO₃^-, thereby reducing friction. Afterwards, the preferred coating is applied to the pistons in a high-power cam-lobe hydraulic motor. The friction torque of the piston-roller friction pairs is tested on a homemade quasi-actual testing rig, and the results showed that the self-reactive lubricating graphite-like coating could reduce the friction torque by 14 %. The present study provides a new approach to improve the mechanical efficiency of hydraulic energy converters, and can also increase the starting torque to reduce the installed power.

液压能量转换器是能够实现机械能与液压能之间转换的部件。它们的功率可高达2 × 106 W或更多。对于一个大功率元件，即使其效率提高1 %，也将带来巨大的节能。然而，目前的研究主要集中在通过增强流体动力效应来提高高速液力能变换器的效率，而对低速液力能变换器（<500 r/min）的研究较少。为此，本研究开发了一种自反应润滑类石墨涂层，专门用于液压能量转换器，以减少导致低速低效率的机械摩擦。自反应润滑类石墨涂层由碳和钨两种元素组成。环块试验结果表明，碳钨原子比为0.51:0.49的涂层在3种载荷条件下具有较低的摩擦和温升。其机理是适当含量的钨能与液压油中的添加剂WS2、PO3-等反应形成润滑膜，从而减少摩擦。然后，将优选涂层应用于大功率凸轮叶液压马达的活塞上。在自制的准实际试验台上对活塞-滚子摩擦副的摩擦力矩进行了测试，结果表明，自反应润滑类石墨涂层可使摩擦力矩降低14% %。本研究为提高液压能量转换器的机械效率提供了一条新的途径，也可以通过提高起动转矩来降低安装功率。

{"title":"Self-reactive lubricating graphite-like coating for low-friction hydraulic energy converters","authors":"Xiaolong Zhang , Kaiming Zheng , Junhui Zhang , Jianxiong Wu , Hongbin Lin , Xiaojiang Lu , Bing Xu , Chao Zhang","doi":"10.1016/j.triboint.2026.111749","DOIUrl":"10.1016/j.triboint.2026.111749","url":null,"abstract":"<div><div>Hydraulic energy converters are components that can realize the conversion between mechanical energy and hydraulic energy. Their powers can be as high as 2 × 10<sup>6</sup> W or more. For a high-power component, even if its efficiency is increased by 1 %, it will bring huge energy savings. However, current research mainly focuses on improving the efficiency of high-speed hydraulic energy converters via enhancing hydrodynamic effect, with little attention paid to low-speed hydraulic energy converters (<500 r/min). For that, this study develops a self-reactive lubricating graphite-like coating specifically for hydraulic energy converters to reduce mechanical friction that leads to low efficiency at low speeds. The self-reactive lubricating graphite-like coating is composed of two elements: carbon and tungsten. The results of the ring-block tests show that the coating with an atomic ratio (carbon: tungsten) of 0.51:0.49 has lower friction and temperature rise under three load conditions. Its mechanism is that an appropriate content of tungsten can react with additives in hydraulic oil to form a lubricating film, such as WS<sub>2</sub> and PO<sub>3</sub><sup>-</sup>, thereby reducing friction. Afterwards, the preferred coating is applied to the pistons in a high-power cam-lobe hydraulic motor. The friction torque of the piston-roller friction pairs is tested on a homemade quasi-actual testing rig, and the results showed that the self-reactive lubricating graphite-like coating could reduce the friction torque by 14 %. The present study provides a new approach to improve the mechanical efficiency of hydraulic energy converters, and can also increase the starting torque to reduce the installed power.</div></div>","PeriodicalId":23238,"journal":{"name":"Tribology International","volume":"218 ","pages":"Article 111749"},"PeriodicalIF":6.1,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

DLC-grease composite lubricating materials with ultra-low wear and ultra-high load capacity for wind turbine bearings 超低磨损、超高负荷风力发电机轴承用dlc -润滑脂复合润滑材料

IF 6.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

Tribology International

Pub Date : 2026-01-23 DOI: 10.1016/j.triboint.2026.111746

Yahui Ren , Jiaying Zhang , Ming Zhang , Ao Xie , Zhenlin Yang , Wenquan Lv , Meirong Cai

A high-performance composite lubricant combining diamond-like carbon (DLC) films and customized grease was developed to address the rapid wear of DLC used as solid lubricants. Under contact stresses of 2.19–3.47 GPa, the composite reduced wear by 97.5%, achieving 1.10 × 10⁻⁸ mm³·N⁻¹·m⁻¹ after 288,000 cycles at 2.19 GPa. Using a DLC film with a dual transition layer enhanced adhesion and tribological performance. The composite forms a stable friction transfer oil film, while nano-additives in the grease further improve lubrication. This solid–liquid system offers low wear, long service life, and reduced maintenance frequency, demonstrating strong potential for wind turbine bearing applications.

为解决类金刚石（DLC）作为固体润滑剂的快速磨损问题，研制了一种结合类金刚石膜和定制润滑脂的高性能复合润滑剂。在2.19 GPa的接触应力为2.19 - 3.47 GPa时，复合材料的磨损降低了97.5%，在2.19 GPa下循环288,000次后达到1.10 × 10−8 mm3·N−1·m−1。采用具有双过渡层的DLC膜增强了附着力和摩擦学性能。复合材料形成稳定的摩擦传递油膜，而润滑脂中的纳米添加剂进一步提高了润滑性能。这种固液系统磨损小，使用寿命长，维护频率低，在风力涡轮机轴承应用中显示出强大的潜力。

引用次数: 0

Effect of the passivation oxide layer on the tribological properties of 316 austenitic stainless steel in B-Li solution 钝化氧化层对316奥氏体不锈钢在B-Li溶液中摩擦学性能的影响

IF 6.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

Tribology International

Pub Date : 2026-01-23 DOI: 10.1016/j.triboint.2026.111748

Pijie Yu , Xuefang Chen , Tianxing Zhao , Yu Yan , Chengcai Li , Jinna Mei , Zhen Cai

To improve the wear resistance of the SUS 316 stainless steel surface, three different passivation treatments were explored, involving acid pickling, applied potential, and applied current density processes. The results indicated that the application of a constant potential yielded the optimal effect, with the optimal constant potential determined as 0.5 V. This was followed by the application of constant current density, while conventional acid pickling yielded the least favorable outcome. After passivation, fine precipitation phase could form, and a layer of precipitation phase was generated after repeated wear, which prevented further wear from occurring. However, excessive passivation, i.e., applying an excessively high current density or an overly high potential, could lead to the formation of pores on the surface. These pores could trap wear debris, causing direct abrasion between the debris and the bulk substrate of the specimens, leading to a deterioration in anti-wear performance.

为了提高SUS 316不锈钢表面的耐磨性，研究了三种不同的钝化处理方法，包括酸洗、施加电位和施加电流密度。结果表明，恒电位的应用效果最佳，确定最佳恒电位为0.5 V。其次是恒流密度的应用，而传统的酸洗效果最差。钝化后可形成细小的析出相，反复磨损后形成一层析出相，防止进一步磨损。然而，过度钝化，即施加过高的电流密度或过高的电位，可能导致表面形成孔隙。这些孔隙可能会捕获磨损碎屑，导致碎屑与试样基体之间的直接磨损，导致抗磨性能下降。

引用次数: 0