Tribology International最新文献

{"title":"Surface roughness prediction model and surface topography analysis of 2.5D-Cf/SiC in two-dimensional ultrasonic assisted grinding based on GA-BP neural network","authors":"","doi":"10.1016/j.triboint.2024.110272","DOIUrl":"10.1016/j.triboint.2024.110272","url":null,"abstract":"<div><div>Because of the anisotropy and non-uniformity, the grinding surface quality of Cf/SiC composites is difficult to be accurately predicted. To better predict the surface quality of 2.5D-Cf/SiC composites, the BP neural network was optimized by genetic algorithm (GA), and the surface roughness prediction model of fiber orientation, ultrasonic amplitude, and machining parameters was established. The empirical formula prediction model of surface roughness was established by the method of multiple linear regression analysis. The results show that the prediction accuracy of GA optimized BP neural network is the best, followed by the empirical formula, and the prediction effect of the BP neural network is the worst. The average absolute percentage error of these three models is 10.045 %, 16.912 % and 26.6245 % respectively. The kinematic models of conventional and two-dimensional ultrasonic-assisted grinding of single particles were established respectively. Based on the kinematic model, the reasons for the reduction of surface roughness by 2D ultrasonic-assisted grinding are explained. According to the orthogonal test results, the surface roughness decreases the most when <em>v</em>_<em>s</em> is 0.66 m/s, <em>v</em>_<em>w</em> is 100 mm/min, <em>a</em>_<em>p</em> is 150 µm along the fiber orientation of 0°, and the maximum percentage of reduction is 53.18 %. Increasing the linear speed, reducing the feed speed, reducing the grinding depth, and applying ultrasound can reduce the extrusion pressure along the axis of 0° fiber, and then reduce the length and depth of cracks and thus reduce the surface defects. The axial shear force of the 90° oriented abrasive particles on the fiber is reduced, thus reducing the surface damage caused by torsional deformation. Reduce 3D surface profile and improve surface quality. The maximum percentage reduction of each parameter index is as follows: root mean square height decreased by 28.8 %, skew decreased by 88.61 %, kurtosis decreased by 48.97 %, maximum crest height decreased by 48.55 %, maximum sag height decreased by 40.09 %, maximum height decreased by 43.93 %, and arithmetic mean height decreased by 26.06 %.</div></div>","PeriodicalId":23238,"journal":{"name":"Tribology International","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357500","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":"Tribological behavior of h-BN/Al2O3 self-lubricating composites in extreme environment—Part Ⅱ: Self-lubrication and mechanism in water-oxygen environment from 300 °C to 1200 °C","authors":"","doi":"10.1016/j.triboint.2024.110269","DOIUrl":"10.1016/j.triboint.2024.110269","url":null,"abstract":"<div><div>The <em>h</em>BN/Al₂O₃ composites exhibit well self-lubricating properties over a wide temperature range in high temperature water-oxygen environments. At temperatures from 300 °C to 1100 °C, the composites maintain a consistently low friction coefficient (0.11–0.16) and show low wear rates of about 10⁻⁶ mm³·N⁻¹∙m⁻¹ orders of magnitude. The thermal expansion effect of <em>h</em>-BN and dynamic water vapor interlaminar diffusion reduced the critical shear strength of <em>h</em>-BN and enhanced interlaminar slip, which in turn improved the tribological properties of the composites. In addition, the stability of the friction interface structure and phase composition was effectively maintained at 1100 °C by the self-volatility of boric acid and the competitive adsorption ability of H₂O molecules.</div></div>","PeriodicalId":23238,"journal":{"name":"Tribology International","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320149","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":"Molecular simulations of amine-based organic additives at a steel surface: Effect of the internal molecular structure on adsorption","authors":"","doi":"10.1016/j.triboint.2024.110258","DOIUrl":"10.1016/j.triboint.2024.110258","url":null,"abstract":"<div><div>Lubricating oils mitigate wear in gears and rolling bearings lengthening the lifespan of drivetrain units for electric vehicles. Amine-based organic additives from the lubricating oil contribute to alleviating wear by adsorbing on rubbing steel surfaces of mechanical contacts and forming anti-wear films. Cross-pin wear experiments suggest that additives with branches in polar heads improve wear protection, while remaining environmentally friendly. Experiments show a reasonable correlation with the energy of adsorption calculated from molecular dynamics simulations at large surface coverages. Whereas adsorption strengths and surface coverages are barely affected by the conformation of alkyl chains (cis/trans), they are affected by the length of branches in polar heads of additives. Results suggest better performances for branch lengths containing 3–4 C atoms.</div></div>","PeriodicalId":23238,"journal":{"name":"Tribology International","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142324007","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":"Effect of element N on microstructure and tribological properties of CoCrFeNiV alloy at severe temperature","authors":"","doi":"10.1016/j.triboint.2024.110266","DOIUrl":"10.1016/j.triboint.2024.110266","url":null,"abstract":"<div><p>In this study, CoCrFeNiV non-equiatomic high entropy alloys (HEAs) with varying N content were prepared using vacuum hot-press sintering. The effects of N content on the alloy's microstructure, mechanical properties, and tribological behavior at different temperatures were investigated. The results indicate that the N-added alloys primarily maintain an FCC phase. With increasing N content, the σ phase in the alloy gradually decreases, while the VN content increases, leading to grain refinement. This results in a 10.7 % increase in hardness, a 9 % increase in compression strength, and a 56 % increase in compression deformation. Below 400 °C, the primary wear mechanisms are adhesive wear, spalling wear, and slight oxidative wear, while above 600 °C, oxidative wear dominates. The addition of N reduced the wear rates of the alloy by 33.8 %, 8.1 %, and 31.3 % at RT, 200 °C, and 600 °C, respectively, and decreases the coefficient of friction at all temperatures. In summary, N addition improves the alloy's tribological performance at various temperatures.</p></div>","PeriodicalId":23238,"journal":{"name":"Tribology International","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142271933","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":"Revealing wear mechanisms of coated shafts in low-speed journal bearings immersed in liquid Lead-Bismuth Eutectic (LBE)","authors":"","doi":"10.1016/j.triboint.2024.110264","DOIUrl":"10.1016/j.triboint.2024.110264","url":null,"abstract":"<div><div>This study investigates wear mechanisms of coated shafts in journal bearings within liquid lead-bismuth eutectic. Shafts were coated with TiAlN, a-C:H, multi-layer TiAlN with sputtered carbon, and chrome plating. Bearings made from sintered iron with carbon inclusions (DEVA 120 and DEVA 121) were tested in LBE at 200 °C and 50 rpm using a dedicated test rig. The a-C:H coatings failed due to tribofilm wear with DEVA 120, while TiAlN coatings failed from fatigue wear with DEVA 120 but succeeded with DEVA 121. Chrome-plated shafts experienced abrasive and adhesive wear with DEVA 121 but survived DEVA 120 due to transfer layer formation. The study highlights the need to understand wear mechanisms and material compatibility to develop durable coatings for harsh environments.</div></div>","PeriodicalId":23238,"journal":{"name":"Tribology International","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320150","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":"Tribological performance of open and closed textured Ti-3Al-2.5V under effect of MoS2 as solid lubricant for aerospace applications","authors":"","doi":"10.1016/j.triboint.2024.110260","DOIUrl":"10.1016/j.triboint.2024.110260","url":null,"abstract":"<div><div>Titanium alloys in the present study are studied for friction and wear behaviour using zirconia counter face. Nanosecond laser was used to fabricate circular and S-shape surface morphologies on Ti-3Al-2.5V substrates. The textured profiles are studied using 3D profilometer and field emission scanning electron microscope for texture ablation and universal tribometer is used to study the friction coefficient and wear behaviour of textured patterns. Friction and wear performance of textured surfaces are studied at applied load of 30, 45, 60 and 75 N. Circular textures of 100 µm while “S” textures of 360 µm length and 200 µm width are fabricated on Ti3Al-2.5-V substrates. Laser parameters used to create textures are laser power, scanning speed and laser frequency of 10-Watt, 350 mm/s and 10 KHz respectively. Friction and wear tests are performed on ablated titanium alloy surfaces for a siding distance of 100 m under the effect of virgin PAO4 lubricant with addition of 1 % by weight MoS2 particles. The results showed an ablation depth of 15.02 µm and 20.48 µm for circular and “S” textures respectively. Both the textured a reduced friction coefficient when lubricated with virgin PAO4 + 1 %MoS₂. At an increasing load from 30 to 75N, friction coefficient decreased from 0.0441 to 0.0382 for circular textures while it almost remained constant from 0.0699 to 0.0641 for “S” textures. “S” textures outperformed circular profiles by reducing friction coefficient by 50 % when MoS₂ particles are added in virgin PAO4 lubricating oil. In terms of wear resistance, open texture profiles were the most promising in contact situations likely to occur in lubrication when 1 % by weight MoS₂ particles were added into lubricant.</div></div>","PeriodicalId":23238,"journal":{"name":"Tribology International","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319831","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":"Moiré-pattern-tuned interlayer friction of two-dimensional α- and β-tellurene via first-principles calculations and experimental validation","authors":"","doi":"10.1016/j.triboint.2024.110261","DOIUrl":"10.1016/j.triboint.2024.110261","url":null,"abstract":"<div><p>Tellurene, as an emerging class of two-dimensional (2D) materials, exhibit distinctive physicochemical properties derived from their varied structural morphologies, particularly in van der Waals (vdW) heterostructures formed between their allotropes, demonstrating substantial potential for superlubricity applications. This study employs a synergistic approach that combines theoretical calculations with experimental investigations to investigate the tribological performance of two tellurene allotropes (α- and β-Te) and their allotropic homojunctions (α-Te/β-Te). The frictional forces of the tellurene systems under varying twist angles were predicted by applying potential energy surfaces (PESs) to the Prandtl–Tomlinson (PT) model. These findings indicate that a reduction in energy barriers leads to decreased frictional forces, thereby enhancing the system's superlubricity. Notably, the frictional response is influenced not only by the interlayer sliding barriers but also by the shape and periodicity of the potential energy landscapes. Furthermore, leveraging the concept of the lubricating figure of merit, this study provides an in-depth analysis of the intrinsic frictional characteristics within a tellurene system. Experimentally, few-layer α- and β-Te tellurene were successfully synthesized, and their interlayer frictional properties were measured, showing high congruence with theoretical predictions. The outcomes reveal the exceptional interlayer frictional performance of tellurene under controlled twist angles, with the β-Te phase exhibiting superior lubricity over α-Te and the formation of an allotropic homojunction (α-Te/β-Te) further enhancing the interlayer superlubricity. These results not only deepen our understanding of the tribological performance of tellurene but also offer a new perspective on the frictional behavior of 2D materials.</p></div>","PeriodicalId":23238,"journal":{"name":"Tribology International","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142271932","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":"High-pressure rheological properties of polyalphaolefin and ester oil blends and their impact on lubrication","authors":"","doi":"10.1016/j.triboint.2024.110262","DOIUrl":"10.1016/j.triboint.2024.110262","url":null,"abstract":"<div><p>Different base oils are often blended to optimize lubrication effectiveness. For blends of polyalphaolefins (PAOs) and ester oils, while their boundary lubrication performance is well-studied, studies on their rheological properties and elastohydrodynamic lubrication (EHL) are limited. This study investigates the viscosity and EHL properties of PAO 8 and pentaerythritol tetra(2-ethylhexanoate) (PEB 8) blends at various blending ratios, pressures, and temperatures. Results showed that under certain conditions, viscosities of the blends are lower than either base oil. This phenomenon was explained from a molecular perspective. The pressure–viscosity relationship was fitted using the Doolittle-Tait free-volume model. Additionally, studies of EHL performance and simulations of different oils correlate the pressure–viscosity to EHL characteristics. These findings provide insights for future lubricant formulation.</p></div>","PeriodicalId":23238,"journal":{"name":"Tribology International","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142271929","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":"Analysis of abrasion wear in particle storage and valve subsystem for falling particle concentrating solar power","authors":"","doi":"10.1016/j.triboint.2024.110259","DOIUrl":"10.1016/j.triboint.2024.110259","url":null,"abstract":"<div><div>Solar energy capture and storage using falling solid particles are being explored for cost-effective next generation concentrating solar power systems. A critical consideration in this technology is the abrasion wear caused by the sliding of the particles under varying speed and pressure over component surfaces. This study presents computational modeling of a subsystem comprising a particle storage bin discharging through a flow control valve that is prone to abrasive wear. The effects of several geometric parameters are systematically evaluated for their impact on spatial and temporal abrasion rates in the storage bin, the control valve, and the valve housing. The findings provide insights into the locations most susceptible to abrasion, and the use of targeted abrasion mitigation coatings is illustrated.</div></div>","PeriodicalId":23238,"journal":{"name":"Tribology International","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320152","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":"Hybrid finite element modeling of subsurface-originated spalling in flexible bearings with hoop stresses","authors":"","doi":"10.1016/j.triboint.2024.110245","DOIUrl":"10.1016/j.triboint.2024.110245","url":null,"abstract":"<div><p>The flexible bearing in a harmonic reducer undergoes structural deformation after being mounted on the cam, causing the bearing to operate under a complex stress state. A hybrid finite element model is developed to investigate crack initiation and propagation in flexible bearings with hoop stress under rolling contact fatigue loading. The model is coupled with continuum damage mechanics, and the damage evolution equation takes the maximum shear stress amplitude as the damage-causing stress since the hoop stress inevitably affects the fatigue life. The model is verified by comparison with the fatigue life of the inner ring without hoop stress. The crack initiation and spalling formation mechanisms in the inner ring assembled with the cam are analyzed in detail. Moreover, the effects of contact load and equivalent interference on the inner ring’s spalling morphology and fatigue life are studied.</p></div>","PeriodicalId":23238,"journal":{"name":"Tribology International","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142271926","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}