Tribology Letters最新文献

{"title":"Alterations in the Molecular Configuration of Mucin Glycoproteins Entail a Loss of Lubricity","authors":"Bernardo Miller Naranjo,&nbsp;Bizan N. Balzer,&nbsp;Oliver Lieleg","doi":"10.1007/s11249-025-02098-6","DOIUrl":"10.1007/s11249-025-02098-6","url":null,"abstract":"<div><p>Mucins, a family of glycoproteins, provide highly efficient lubrication on the eyes, in the mouth, and in the gastrointestinal tract of mammals. Although two key mechanisms responsible for the outstanding lubricity of mucin solutions, <i>i.e</i>., sacrificial layer formation and hydration lubrication, have been identified, recent research indicates that the complex structure of mucins, <i>e.g</i>., the presence of folded domains in the termini of the glycoproteins, might also be relevant for the tribological performance of mucin solutions. Here, we manipulate the molecular configuration of three different mucins (<i>i.e.</i>, porcine gastric mucin MUC5AC, bovine submaxillary mucin MUC5B, and porcine intestinal mucin MUC2) by treating the glycoproteins either with the crosslinking agent glutaraldehyde (GA) or with the denaturing agent guanidine hydrochloride (Gua) and assess the ensuing consequences of those treatments. Although we observe a clear reduction in the lubricity of all mucin solutions upon treatment, neither mucin aggregation, nor a reduction of mucin hydration, nor an altered adsorption behavior of mucins to hydrophobic PDMS surfaces can account for this effect. Instead, we suggest that the treatments prevent the stretching of mucins and/or the unfolding of the mucin termini, and both processes may play an important role in retarding the force-induced desorption of mucins from surfaces as required for efficient hydration lubrication. Our results pinpoint molecular mechanisms which—to date—were not sufficiently considered for macromolecular lubricants. A better characterization of these molecular mechanisms will not only deepen our understanding of mucin-based lubricants but will also open the path for the development of more efficient, bio-inspired lubricants.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div><div><p>The stretching of the mucin glycoproteins and the unfolding of their hydrophobic termini contribute to the lubricity of mucin solutions. Suppressing this stretching/unfolding results in reduced lubricity</p></div></div></figure></div></div>","PeriodicalId":806,"journal":{"name":"Tribology Letters","volume":"74 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11249-025-02098-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145982821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantifying Tactile Perception of Fabrics Using Both Frictional and Acoustic Methods","authors":"Laure Kyriazis,&nbsp;Tugce Caykara,&nbsp;Daniel Ingo Hefft,&nbsp;Alberto Martinez,&nbsp;Zhenyu Jason Zhang","doi":"10.1007/s11249-026-02107-2","DOIUrl":"10.1007/s11249-026-02107-2","url":null,"abstract":"<div><p>Skin friction underpins tactile perception of formulated products, such as cosmetics, fabric softeners, and surface coatings, that are designed to deliver satisfactory tactile sensory properties. Establishing the correlation between the tribological properties of skin contacts and tactile perception is therefore critical. We have developed a novel approach to acquire the acoustic emission (AE) signal generated by human finger sliding against fabric and non-fabric substrates, whilst capturing its frictional characteristics with a force plate. Principal Component Analysis was deployed to construct clusters formed for each material based on the sensory evaluation, and to establish the correlation between frictional and acoustic emission data. Our results show that the planar solid substrates could be discriminated solely based on the friction results, whilst the fabric materials were not significantly discriminated by the Coefficient of Friction values. However, AE was able to differentiate the fabric substrates successfully, and therefore evidences a promising potential to provide complementary information on tactile perception whilst being versatile enough as a standalone method.</p></div>","PeriodicalId":806,"journal":{"name":"Tribology Letters","volume":"74 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11249-026-02107-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145982820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Study on Grease Lubrication Characteristics Based on Micro-Oil Supply","authors":"Jinglong Jia,&nbsp;Xinming Li,&nbsp;Xuyang Jin,&nbsp;Yanqiang Hu,&nbsp;Changsong Liu,&nbsp;Qinghua Bai,&nbsp;Kecheng Zhou","doi":"10.1007/s11249-025-02104-x","DOIUrl":"10.1007/s11249-025-02104-x","url":null,"abstract":"<div><p>During bearing operation, lubricating grease is mechanically displaced toward track peripheries by rolling elements. With limited replenishment capacity from flanking grease bands, lubrication starvation conditions readily develop within the contact zone. To address this problem, a strategy for improving the lubrication state through external micro base oil supply is proposed in this study. A dedicated oil supply system has been constructed to achieve scheduled-metered-bearing-specific delivery of trace base oil with precision. The effects of single and periodic multiple base oil supplies on the evolution of the lubricating film in the contact area under pure rolling conditions were investigated using a ball-on-disc optical interference point contact measurement apparatus. The time required for the oil film to reach dynamic equilibrium under different oil supply rates and intervals was compared. And the mechanism of extending the service life of grease by external oil supply was analyzed. The results demonstrated that the film thickness in the contact area can be instantaneously enhanced by introducing a small amount of base oil during operation. The duration of the entire dynamic equilibrium process from film thickness increase to natural recession back to the initial thickness was influenced by different oil supply rates and periodic supply intervals.</p></div>","PeriodicalId":806,"journal":{"name":"Tribology Letters","volume":"74 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145887070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simultaneously Improving the Eco-friendliness and Tribological Performance of Lithium Grease by Cellulose Nanocrystal Additive","authors":"Jingwen Li,&nbsp;Chen Du,&nbsp;Tobias Amann,&nbsp;Miguel A. Delgado,&nbsp;Moisés García-Morales,&nbsp;Chengqing Yuan,&nbsp;Ke Li","doi":"10.1007/s11249-025-02099-5","DOIUrl":"10.1007/s11249-025-02099-5","url":null,"abstract":"<div><p>The development of eco-friendly lubricating additives attracts more and more research attention. However, their tribological performance remains a challenge compared to conventional metal thiophosphate additives in the industry. This study investigated the use of cellulose nanocrystals (CNCs) as an eco-friendly additive to partially replace conventional metal thiophosphate additives in a commercial lithium grease. The friction tests showed that compared to the Full grease containing the standard content of molybdenum dialkyl dithiophosphate (MoDTP) and zinc dialkyl dithiophosphate (ZDDP), the Half grease (i.e., the content of MoDTP and ZDDP was halved based on the Full grease) performed superior anti-friction and anti-wear ability by incorporating 0.5 wt% CNC nanoparticles. Surface analysis of the friction pairs revealed that CNC nanoparticles facilitated lubrication through a mending effect on the worn surfaces. Moreover, the function of CNCs became even more effective under high loads, resulting in an excellent extreme-pressure capacity. This study suggests that CNCs are a promising bio-based additive that can simultaneously improve the eco-friendliness and tribological performance of lubricating greases.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":806,"journal":{"name":"Tribology Letters","volume":"74 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145887046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation on Elevated Temperature Tribological Properties of Barrel Steel Pairing With Brass","authors":"Haiyue Ren,&nbsp;Yulei Yang,&nbsp;Kedong Zhou,&nbsp;Yilin Xie,&nbsp;Mo Yang,&nbsp;Lei He,&nbsp;Di Zhang","doi":"10.1007/s11249-025-02103-y","DOIUrl":"10.1007/s11249-025-02103-y","url":null,"abstract":"<div><p>The tribological behavior of barrel steel paired with brass, a critical interface in artillery systems, remains underexplored despite its direct impact on barrel lifespan. This study systematically investigates the tribological behavior and underlying mechanisms of this specific pairing across a temperature spectrum (RT, 200 °C, 400 °C, and 600 °C). The two materials exhibited distinctly different wear rate trends: the barrel steel's wear rate peaked at 200 °C before declining, contrary to the typical thermal softening trend. While the brass counterpart exhibited a high wear rate at RT, which then decreased significantly at elevated temperatures. A key finding is the discovery of a nanocrystalline-structured tribolayer that forms at 600 °C. This tribolayer is characterized by a distinct stratified architecture, composed of a Cu-rich top layer, a fine-grained intermediate zone, and a coarse-grained substrate, demonstrates exceptional wear resistance. This work reveals the transition in dominant wear mechanisms from adhesive or abrasive to oxidative wear, providing novel insights into the 'copper fouling' phenomenon and a scientific basis for developing long-life barrel materials.</p></div>","PeriodicalId":806,"journal":{"name":"Tribology Letters","volume":"74 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145831423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Key Role of Overbased Detergents in Load-Induced Friction Reduction for Steel and DLC-Involved Contacts","authors":"Y. Guan,&nbsp;J. Galipaud,&nbsp;F. Dubreuil,&nbsp;J. Dufils,&nbsp;E. Macron,&nbsp;F. Dassenoy,&nbsp;M. I. de Barros Bouchet","doi":"10.1007/s11249-025-02102-z","DOIUrl":"10.1007/s11249-025-02102-z","url":null,"abstract":"<div><p>The rising application of diamond-like carbon (DLC) coatings on engine components requires a thorough examination of the interaction processes between DLC and fully formulated engine oil. This study demonstrates the critical role of overbased detergent additives, both in fully formulated and model lubricants, in reducing friction as a function of contact pressure in the boundary lubrication regime for hydrogen-containing DLC a-C:H involved tribo-pairs. Transmission Electron Microscope (TEM) reveals that the calcite formed during friction from overbased detergents plays a significant role in decreasing friction under high contact loads. Furthermore, the interaction between pressure conditions and the nature of the counterfaces dictates the type of calcium carbonate polymorph formed in the sliding contact, which significantly affects the tribological performance of the lubricant.</p></div>","PeriodicalId":806,"journal":{"name":"Tribology Letters","volume":"74 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145831421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multiscale Mechanics of Granular Biofilms","authors":"Lisa K. Månsson,&nbsp;Anna E. Warsaw,&nbsp;Elizabeth G. Wilbanks,&nbsp;Angela A. Pitenis","doi":"10.1007/s11249-025-02101-0","DOIUrl":"10.1007/s11249-025-02101-0","url":null,"abstract":"<div><p>Biofilms produce and maintain extracellular polymeric substances (EPS) essential for their form and function. While biofilms are commonly lamellar and frequently targets of removal, granular biofilms are increasingly incorporated into water treatment strategies. In both cases, the EPS (mainly consisting of proteins, polysaccharides, and extracellular DNA) is largely responsible for their persistence. Unlike many granular biofilms, which are formed in engineered industrial bioreactors, the “pink berry” consortia is a naturally occurring and robust granular biofilm of photosynthetic bacteria, found only in intertidal pools of salt marshes around Woods Hole, Massachusetts (USA). The pink berry biofilm’s unique ecological niche has sparked over three decades of study, yet their mechanical properties are completely unknown. Here, we characterized the structural and mechanical landscape of pink berry granules to determine the extent to which microscale heterogeneity influences macroscale material properties. We performed microindentation measurements on intact granules and nanoindentation measurements on thin sections. We report that intact pink berry granules exhibited low reduced elastic moduli (<i>E*</i>_{pink berry} ≈ 0.5–10 kPa) and fast stress relaxation times (<i>τ</i>_1/2 ≈ seconds), consistent with previous investigations of soft and viscoelastic biofilms. Nanomechanical measurements of thin pink berry sections revealed two mechanically distinct domains: a very soft extracellular polymeric substance (EPS) matrix surrounding stiffer microcolonies of purple sulfur bacteria (PSB). Light sheet fluorescence microscopy revealed the spatial organization and distribution of cell-dense PSB microcolonies (34 vol%) within EPS matrix (66 vol%), suggesting the nanomechanical behavior of EPS dominates macroscale pink berry mechanics. Our multiscale experimental approach combining mechanics and imaging may be broadly applicable to investigations of complex soft materials, from synthetic hydrogel composites to biologically heterogeneous spheroids, organoids, and tissues.</p></div>","PeriodicalId":806,"journal":{"name":"Tribology Letters","volume":"74 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11249-025-02101-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145779134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Substrate Surface Finish on the Wear and Corrosion Behaviour of AlTiN/AlTiCrN Coatings","authors":"Musa Muhammed,&nbsp;Mousa Javidani,&nbsp;Majid Heidari,&nbsp;Tom Levasseur,&nbsp;Mohammad Jahazi","doi":"10.1007/s11249-025-02100-1","DOIUrl":"10.1007/s11249-025-02100-1","url":null,"abstract":"<div><p>This study investigates the influence of substrate surface finish on the morphological, mechanical, and microstructural properties of AlTiN/AlTiCrN coatings on AISI A8 tool steel, and how this cascade of property changes collectively dictates the wear and corrosion behaviour of the coated tool steels. The wear resistance was evaluated as per the ASTM G65 test, while the corrosion performance was assessed using electrochemical impedance spectroscopy and potentiodynamic polarization techniques. Surface roughness was measured using profilometry, while the hardness (H) and elastic modulus (E) were determined via nanoindentation. Microstructural characterization was carried out using scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction techniques. The results showed that increasing the average substrate roughness by about 500-fold (from 0.003 to 1.7 µm) led to a relatively modest rise of about 22% in the wear rate (from 1.8 to 2.2 × 10⁻⁴ mm³/Nm). This reduction in the wear performance of the coatings on the rougher substrates was attributed to lower hardness, a reduced H/E ratio, and an elevated surface roughness of the coatings. Similarly, the coating’s corrosion resistance deteriorated with increasing surface roughness, as reflected by a decline in protective efficiency (from 77 to 58%) and an increase in porosity (from 0.27 to 0.49%). This observation was linked to the cumulative effect of the reduction in (111) crystallographic orientation, the presence of larger macroparticles, and an elevated surface roughness of the coatings on the rougher substrate finish. Overall, these findings underscore the potential of a smoother AISI A8 substrate surface finish to simultaneously improve the wear and corrosion performance of AlTiN/AlTiCrN coatings by promoting better coating morphology, mechanical strength, and electrochemical stability.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":806,"journal":{"name":"Tribology Letters","volume":"74 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145779133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Full-Film EHD Friction in FM-Containing Oils","authors":"Mao Ueda,&nbsp;Takayuki Tokoroyama,&nbsp;Naoki Yamashita,&nbsp;Tomoko Hirayama,&nbsp;Noritsugu Umehara","doi":"10.1007/s11249-025-02096-8","DOIUrl":"10.1007/s11249-025-02096-8","url":null,"abstract":"<div><p>The reduction of elastohydrodynamic (EHD) friction has become increasingly important to improve the efficiency of mechanical components. This study investigated the effect of friction modifiers (FMs) on full-film EHD friction using a ball-on-disc tribometer to elucidate the underlying mechanisms by which FMs affect full-film EHD friction. It was found that glycerol monooleate (GMO) lowered full-film EHD friction more than glycerol tris(2-ethylhexanoate) (GTE). This effect became more pronounced with increasing concentration of FMs. Neutron reflectometry (NR) and in situ reflectance spectroscopy suggested that GMO formed a thicker and denser adsorption film on surfaces than GTE, correlating directly with full-film EHD friction reduction. One of the possible mechanisms is that FMs, particularly GMO, adsorb on surfaces and may form oleophobic planes, where methyl groups are aligned in the outermost region of the adsorption film. A bulk base oil may flow more easily on such planes due to an interfacial slip than on steel surfaces. This reduces full-film EHD friction. The insights obtained in this study can be used to the design of lubricants that reduce full-film EHD friction.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":806,"journal":{"name":"Tribology Letters","volume":"74 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11249-025-02096-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145646246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acoustic Emission Diagnosis of Lubricant Water Contamination Fault by Using Adaptive Multi-fidelity Bayesian Optimization","authors":"Ziyang Zhu,&nbsp;Jiaojiao Ma,&nbsp;Dongming Xiao,&nbsp;Xuejun Li,&nbsp;Fengshou Gu,&nbsp;Andrew D. Ball","doi":"10.1007/s11249-025-02097-7","DOIUrl":"10.1007/s11249-025-02097-7","url":null,"abstract":"<div><p>In rotating machinery, water contamination in lubricants can lead to oil film failure and exacerbate equipment wear. The acoustic emission (AE) technology demonstrates superior performance over traditional detection methods for early fault detection due to its sensitivity to weak signals. Regarding the specific features of AE signals during oil film shearing, the traditional Bayesian method lacks comprehensive diagnosis and is constrained by single-fidelity optimization, dedicating most evaluations to high-cost configurations. Accordingly, this paper proposes an adaptive Multi-fidelity Bayesian Optimization (MFBO) method for detecting water contamination in lubricants. The approach denoises acoustic emission (AE) signals by combining the detection index (DI) and the interquartile range (IQR) with wavelet packet transform (WPT), which markedly improves the signal-to-noise ratio. Within MFBO, an adaptive penalty parameter <i>α</i> dynamically adjusts to reduce costly evaluations. This framework is used to optimize CNN hyperparameters, including the learning rate, mini-batch size, and number of training epochs. Experiments on twelve groups at different shear rates yield a recognition accuracy of 99.15% for water contamination, representing an 18.48% improvement over the non-optimized baseline; introducing α further reduces computation time by 7.35%. Overall, the method achieves an effective balance between exploration and exploitation, maintaining reliable identification across varying moisture levels.</p></div>","PeriodicalId":806,"journal":{"name":"Tribology Letters","volume":"74 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145646248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}