Friction最新文献

{"title":"Modeling and experimental research on rough tooth surface contact fatigue calculation considering hardness gradient and residual stress","authors":"Yuqin Wen, Wei Zhou, Jinyuan Tang","doi":"10.26599/frict.2025.9441041","DOIUrl":"https://doi.org/10.26599/frict.2025.9441041","url":null,"abstract":" <p>Surface integrity parameters such as surface topography, hardness gradient, and residual stress have significant impacts on contact fatigue of tooth surface. To meet the needs of efficient and stable contact fatigue calculations, efficient mixed lubrication calculations were achieved in this study by dividing the lubrication region and reconstructing the asperities. By considering the influence of the residual stress and hardness gradient on the tooth surface, a calculation model for gear contact fatigue was established and verified based on fatigue tests of gear contact. The results are as follows: (1) Due to the influence of rough surfaces, there were two high-stress peaks in the near-surface layer (6 μm) and sub-surface layer (245 μm) of the tooth surface, which corresponded to micro-pitting and pitting areas, respectively. (2) Ignoring the influence of various integrity parameters led to errors of several orders of magnitude in predicting the contact fatigue life of the tooth surface. (3) The fatigue failure area predicted by the model proposed in this paper was consistent with the experimental results, and the average error in the fatigue life was approximately 14.3%. The method proposed in this paper can effectively predict the contact fatigue life and dangerous areas of the tooth surface, with advantages of high computational efficiency and good stability, laying a foundation for research on tooth surface anti-fatigue design.</p> ","PeriodicalId":12442,"journal":{"name":"Friction","volume":"30 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144371084","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}

{"title":"Development of a machine learning-based surrogate model for friction prediction in textured journal bearings","authors":"Yujun Wang, Georg Jacobs, Shuo Zhang, Benjamin Klinghart, Florian König","doi":"10.26599/frict.2025.9441051","DOIUrl":"https://doi.org/10.26599/frict.2025.9441051","url":null,"abstract":" <p>Surface textures in journal bearings offer significant potential for reducing friction and enhancing energy efficiency. However, the complexity of texture configurations necessitates an accurate and efficient performance prediction model to properly design textured journal bearings. To address this issue, this study develops a machine learning (ML)-based surrogate model to predict friction in textured journal bearings. First, computational fluid dynamics (CFD) models employing a dynamic mesh algorithm are developed to generate accurate data sets. Furthermore, three ML methods are trained and compared to select the most suitable prediction method: artificial neural network (ANN), support vector regression (SVR), and Gaussian process regression (GPR). Among these ML methods, ANN shows the best prediction performance. Given the high computational cost of CFD simulations, the prediction accuracy of the ANN-based surrogate model is further enhanced without the need for additional data sets. This enhancement is achieved through an architecture design based on cross-validation and further optimization utilizing the genetic algorithm. Eventually, the average prediction accuracy is improved to 98.81% from 95.89%, with the maximum error reduced to 3.25% from 13.17%. These findings demonstrate the potential of ML in the performance prediction in textured journal bearings and provide a promising approach for broader applications in developing highly efficient and accurate ML-based surrogate models, particularly in cases with limited available training data sets.</p> ","PeriodicalId":12442,"journal":{"name":"Friction","volume":"17 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144371085","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}

{"title":"An improved equivalent viscosity model for the bubbly oil under high shear rate","authors":"Shaohua Li, Shuyun Jiang, Xiaohui Lin, Chibin Zhang","doi":"10.26599/frict.2025.9441042","DOIUrl":"https://doi.org/10.26599/frict.2025.9441042","url":null,"abstract":" <p>Shear-thinning effect of pure oil and distribution of bubble size are essential factors affecting the viscosity of bubbly oil. This study aims to establish an improved equivalent viscosity model for bubbly oil by considering the shear-thinning effect and the bubble distribution effect. Based on the equivalence principle of frictional resistance, the viscosity of pure oil considering the shear thinning effect is derived; based on the energy conservation principle, the viscosity increment due to bubble deformation is derived. A series of experiments, including generation of bubbly oil, bubble observation, and measurement of bubble oil viscosity, are conducted to validate the model established. The simulated and experimental results indicate that the improved equivalent viscosity model of bubbly oil is more accurate than the traditional model. Notably, the effect of oil shear thinning on the equivalent viscosity is much more obvious than the effect on the distribution of bubble size.</p> ","PeriodicalId":12442,"journal":{"name":"Friction","volume":"19 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144370934","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}

{"title":"Macroscale superlubricity enabled by the synergy effect of oil and S–C co infiltration coating on 20CrMnTi steel surface","authors":"Guotao Zhang, Lexin Song, Zhen Ma, Zhaochang Wang, Baohong Tong, Yanguo Yin","doi":"10.26599/frict.2025.9441137","DOIUrl":"https://doi.org/10.26599/frict.2025.9441137","url":null,"abstract":"<p>To explore the macroscopic superlubricity in industrial field, S-C co infiltration treatment refers to the sulfurization on the carburized gear steel to achieve a synergy lubrication effect. It was found that the carburized layer at the bottom provides high-strength support. And the surface sulfurized layer with pores immersed oil shows good solid-liquid synergistic lubrication to realize stable superlubricity under the load of 0~800 N. Although it lost the stable superlubricity after increasing the load to 1200 N, the tribological coefficient and wear depth were reduced by 72.9% and 19.4% respectively compared with the original surface. This research proposes a novel oil-solid synergistic superlubricity system, which exhibits significant potential for practical applications.</p>","PeriodicalId":12442,"journal":{"name":"Friction","volume":"16 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144341181","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}

{"title":"Double-layer transfer film enabled by graphene oxide-assembled hydrophobic ionic liquids for low friction under high humidity","authors":"Haijie Chen, Zihao Zhang, Zhiwen Zheng, Jingjing Zhang, Dan Qiao, Chao Zhang","doi":"10.26599/frict.2025.9441135","DOIUrl":"https://doi.org/10.26599/frict.2025.9441135","url":null,"abstract":"<p>Achieving outstanding friction reduction and wear resistance on engineering steel by utilizing graphene oxide (GO) based films has attracted growing interest, when given its easy shear, modification and availability. However, maintaining excellent friction performance under high relative humidity (RH) over a long duration is a major challenge for GO film. Therefore, we report that a double-layers transfer film enabled by the unique lubrication mechanism which based on GO interface assembly composite hydrophobic ionic liquids (ILs) triggers excellent tribological property under high humidity. Moreover, the film (SS-GO-ILs) showed excellent tribological properties in the air (average friction coefficient of 0.24, wear volume of 2.54×10^-7 mm³) and 85%RH (average friction coefficient of 0.28, wear volume of 2.33×10^-7 mm³), and the wear volume is reduced to one-thousandth of the SS-GO film. At 85%RH, MD simulation results demonstrated that the interaction between GO and ILs was weakened under the action of water molecules. The unique lubrication mechanism was enabled by the double-layers transfer film formed on the steel balls, along with tribo-chemical reaction and hydrolysis that create an adaptable easy-shear interface.</p>","PeriodicalId":12442,"journal":{"name":"Friction","volume":"25 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144341180","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}

{"title":"A novel tribometer for investigating wear behavior of axial-symmetric vectoring exhaust nozzle regulation mechanism under extreme conditions","authors":"Songkai Liu, Zhixuan He, Kaiyi Huang, Ke He, Zhen Li, Zhinan Zhang","doi":"10.26599/frict.2025.9441139","DOIUrl":"https://doi.org/10.26599/frict.2025.9441139","url":null,"abstract":"<p style=\"text-indent: 24.0pt; line-height: 200%;\"><span lang=\"EN-US\">Axial-Symmetric Vectoring Exhaust Nozzles (AVENs) enhance aero-platform maneuverability by dynamically modulating exhaust flow. However, the durability of their regulation mechanisms remains a challenge due to high temperature, heavy load, and complex multi-body kinematics. It is crucial to conduct experiments to investigate AVEN-specific tribological behavior under extreme conditions. This study develops a novel tribometer to simulate coupling kinematic of roller-cam, pin-hinge and ball-socket joints, high-temperature operation (up to 800°C), and heavy-load conditions (up to 30 kN). The setup features a dual-configuration fixture, a hybrid motion-loading module, and a multi-layer heating and cooling system. The motion-loading module, comprising two electric cylinders, a hydraulic cylinder, and a rotary motor, enables precise replication of fixed and flexible kinematics under multi-force coupling. A dual-input, dual-output feedback system ensures accurate force and displacement control. Preliminary experiments validated the tribometer’s effectiveness and revealed dominant wear mechanisms, providing insights for AVEN durability improvements and tribological studies of complex aerospace mechanisms.</span></p>","PeriodicalId":12442,"journal":{"name":"Friction","volume":"644 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144341183","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}

{"title":"Temperature-insensitive ultralow lubrication of sputtered WSN coatings: Insights into constant, ramping and cycling temperatures from room to 400 ℃","authors":"Z. H. Liu, J. H. Qi, S. Li, X. P. Dong, W. M. Rainforth, Y. T. Pei, Y. Chen, X. L. Zhong, M. W. Bai, J. T. M. De Hosson, H. T. Cao","doi":"10.26599/frict.2025.9441138","DOIUrl":"https://doi.org/10.26599/frict.2025.9441138","url":null,"abstract":"<p>This study introduces a breakthrough in self-lubricating WSN coatings, engineered for demanding applications across industries requiring adaptive durability and high performance. Deposited via non-equilibrium reactive magnetron sputtering in N₂-containing atmospheres, the WSN coatings demonstrate exceptional tribological behavior across a range of extreme conditions, including constantly discrete high temperatures, ramping temperature either in heating or cooling and wide temperature cycling from room temperature to 400 °C. The WSN coatings exhibit an extremely low coefficient of friction (CoF=0.02) up to 400 °C, with high thermal stability and superior triboperformance. Moreover, the coatings possess favorable tribo-reversibility under 400 °C ↔ room temperature cycles. Transmission electron microscopy analysis verified the self-lubricating, tribologically reversible, and ultralow lubrication mechanisms of the WSN coatings. Although under high-temperature tribosliding, the WS₂ layer still dynamically forms a self-organized, layered interface structure that continuously adapts to sliding conditions, ultimately enabling sustained superlubricity and tribological reversibility. Oxidation during high-temperature tribosliding actually has only a minor degrading effect on friction provided that the coatings retain sufficient sulfur to predominantly form WS₂ lubricant agents. This study provided novel insights into the development of advanced tribocoatings exhibiting adaptive ultra-lubrication in wide variable temperature conditions.</p>","PeriodicalId":12442,"journal":{"name":"Friction","volume":"45 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144341182","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}

{"title":"Differential hydration lubrication performance of polyelectrolyte-modified UHMWPE promoted by diverse charge characteristics","authors":"Jianing Xu, Tianyi Han, Chenhui Zhang, Jianbin Luo","doi":"10.26599/frict.2025.9441006","DOIUrl":"https://doi.org/10.26599/frict.2025.9441006","url":null,"abstract":" <p>Hydrated ions can achieve exceptional hydration lubrication through their adsorption onto oppositely charged surfaces. Similarly, the charge characteristics of polyelectrolytes are expected to significantly impact the hydration lubrication performance of polyelectrolyte-modified materials through the adsorption of counterions with surrounding hydration layers of different strength. To verify this hypothesis, a comprehensive polyelectrolyte-embedded modification on ultra-high molecular weight polyethylene (UHMWPE) employing polyanionic, polyzwitterionic, and polycationic brushes was performed for the construction of modified materials with diverse surface charge characteristics. Subsequently, the polyelectrolyte-modified UHMWPE were subjected to systematic investigations to understand the effect of polyelectrolyte charges on the surface hydration and lubrication performance under varying electrolyte conditions, including concentration and types of counterions. All polyelectrolyte-modified UHMWPE displayed more effective hydration lubrication with increasing ion concentrations, showcasing the contribution of hydrated counterions in the load-bearing and friction reduction of charged polyelectrolytes. A vertical comparison among different polyelectrolytes revealed that, polyanionic poly(3-sulfopropyl methacrylate potassium) (PSPMK), characteristic of the highest surface charge density, exhibited the strongest hydration lubrication that enables macroscale superlubricity. At the same time, a horizontal comparison of varying counterions in the solutions within each polyelectrolyte-modified UHMWPE displayed a sequence of hydration lubrication performance with more strongly hydrated ions resulting in lower friction and wear. These findings elucidate the impact of polyelectrolyte charge characteristics on hydration lubrication, highlighting the combined influence of ion adsorption density, determined by intrinsic surface potential, and the ionic hydration strength of surrounding counterions in determining the overall hydration lubrication performance of modified UHMWPE.</p> ","PeriodicalId":12442,"journal":{"name":"Friction","volume":"18 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144341184","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}

{"title":"Enhancing tribological performance of metal matrix composites via high-quality micro-dimples patterned by elliptical vibration texturing","authors":"Qilin Li, Peiyuan Ding, Zhiwei Li, Quanzhao Wang, Pingfa Feng, Jianjian Wang","doi":"10.26599/frict.2025.9441140","DOIUrl":"https://doi.org/10.26599/frict.2025.9441140","url":null,"abstract":"<p>Texturing micro-dimple structures on silicon carbide particle-reinforced aluminum matrix (SiC_p/Al) composites is a promising technical approach to enhance their tribological performance. However, due to the heterogeneous material property, the fabrication of high-quality micro-dimples on SiC_p/Al composites by methods like laser texturing is challenging. This study introduces elliptical vibration texturing (EVT) to fabricate high-quality micro-dimples on SiC_p/Al through controlled material removal. A kinematic model was developed to predict dimple geometries, and experimental results revealed that EVT can effectively create uniform micro-dimple textures with minimal surface damage. The process involves a transition between ductile and brittle-ductile mixed removal modes, which promotes surface integrity. Tribological tests demonstrated that textured surfaces achieved a 40% reduction in the friction coefficient under lubricated conditions compared with untextured surfaces. Deeper dimple textures (6 μm) exhibited superior performance under higher loads owing to enhanced lubricant retention. This study presented a practical approach for improving the tribological performance of metal matrix composites for aerospace applications.</p>","PeriodicalId":12442,"journal":{"name":"Friction","volume":"1 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144341186","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}

{"title":"Film forming and lubrication mechanisms of whey proteins and mucin","authors":"Yating Huang, Yongbao Wei, Yan Wang, Zhihua Pang","doi":"10.26599/frict.2025.9441038","DOIUrl":"https://doi.org/10.26599/frict.2025.9441038","url":null,"abstract":" <p>The sensory perception of whey protein is closely related to its ability to form films on the oral surface and the structure of the resulting film. Mucins, key components of human saliva, play a significant role in this film-forming process and in oral lubrication. Direct exploration of their film-forming behavior in the oral environment is crucial for understanding the mechanisms of mouthfeel. Subsequent adsorption experiments revealed that whey protein isolate (WPI) and mucin molecules could form hydrated layers immediately on gold or polydimethylsiloxane (PDMS) surfaces. Moreover, mucin exhibited a stronger adsorption capacity, displacing WPI molecules adsorbed on the surfaces. Conversely, preformed mucin layers facilitated the formation of a mucin-WPI hybrid layer. The film thickness and quantity of adsorbed mass increased over time, following the pseudo-second-order (PSO) model, indicating strong chemical bonding between the molecules and the substrate surface. The lubrication properties of the hybrid layer were confirmed via an optical interference approach. Under Hertzian contact at a speed of 500 mm/s and a load of 10 N, a thin film lubrication (TFL) state was observed, with the highest film thickness reaching approximately 30 nm. In contrast, under compliant contact with a 10 mN load, the lubrication state transitioned from TFL to soft-EHL at an entrainment speed of just 2.5 mm/s, with the film thickness reaching nearly 350 nm. The presence of mucin enhanced the consistency of WPI adsorption, leading to a thicker and more reliable film. Further investigation revealed that the addition of mucin reduced friction by 30%–50% in both the boundary and TFL regimes. The superior lubrication performance of the mucin/WPI emulsion was attributed to the formation of the hybrid layer and the mucoadhesive properties of mucin. This study provides guidance for the use of mucin to increase the smoothness of WPIs and alleviate their mouth-drying effects.</p> ","PeriodicalId":12442,"journal":{"name":"Friction","volume":"19 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144334963","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}