Previous Issue
Volume 13, August
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
4.5
2.9
Journals
Lubricants
Volume 13
Issue 9
share announcement

Lubricants, Volume 13, Issue 9 (September 2025) – 5 articles

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
15 pages, 9186 KiB  
Article
Al2O3/PTFE Composites for Marine Self-Lubricating Bearings: Modulation Mechanism of Alumina Particle Size on Material Mechanical Properties and Tribological Behavior
by Guofeng Zhao and Shifan Zhu
Lubricants 2025, 13(9), 377; https://doi.org/10.3390/lubricants13090377 (registering DOI) - 23 Aug 2025
Abstract
Polytetrafluoroethylene (PTFE) is one of the alternative materials suitable for seawater-lubricated bearings, favored for its excellent corrosion resistance and good self-lubricating properties. As marine equipment develops towards higher load, higher reliability, and longer service life, more stringent requirements are imposed on the wear [...] Read more.
Polytetrafluoroethylene (PTFE) is one of the alternative materials suitable for seawater-lubricated bearings, favored for its excellent corrosion resistance and good self-lubricating properties. As marine equipment develops towards higher load, higher reliability, and longer service life, more stringent requirements are imposed on the wear resistance of bearing materials. However, traditional PTFE materials struggle to meet the performance requirements for long-term stable operation in modern marine environments. To improve the wear resistance of PTFE, this study used alumina (Al2O3) particles with three different particle sizes (50 nm, 3 μm, and 80 μm) as fillers and prepared Al2O3/PTFE composites via the cold pressing and sintering process. Tribological performance tests were conducted using a ball-on-disk reciprocating friction and wear tester, with Cr12 steel balls as counterparts, under an artificial seawater lubrication environment, applying a normal load of 10 N for 40 min. The microstructure and wear scar morphology were characterized by scanning electron microscopy (SEM), and mechanical properties were measured using a Shore hardness tester. A systematic study was carried out on the microstructure, mechanical properties, friction coefficient, wear rate, and limiting PV value of the composites. The results show that the particle size of Al2O3 particles significantly affects the mechanical properties, friction coefficient, wear rate, and limiting PV value of the composites. The 50 nm Al2O3/PTFE formed a uniformly spread friction film and transfer film during the friction process, which has better friction and wear reduction performance and load bearing capacity. The 80 μm Al2O3 group exhibited poor friction properties despite higher hardness. The nanoscale Al2O3 filler was superior in improving the wear resistance, stabilizing the coefficient of friction, and prolonging the service life of the material, and demonstrated good seawater lubrication bearing suitability. This study provides theoretical support and an experimental basis for the design optimization and engineering application of PTFE-based composites in harsh marine environments. Full article
►▼ Show Figures

Figure 1

21 pages, 4542 KiB  
Article
Tribo-Dynamics and Fretting Behavior of Connecting Rod Big-End Bearings in Internal Combustion Engines
by Yinhui Che, Meng Zhang, Qiang Chen, Hebin Ren, Nan Li, Shuo Liu and Yi Cui
Lubricants 2025, 13(9), 376; https://doi.org/10.3390/lubricants13090376 (registering DOI) - 23 Aug 2025
Abstract
With the increased power density of internal combustion engines (ICE) and growing demands for lightweight design, the connecting rod big-end bearings are subjected to significant alternating loads. Consequently, the interference–fit interfaces become susceptible to fretting damage, which can markedly shorten engine service life [...] Read more.
With the increased power density of internal combustion engines (ICE) and growing demands for lightweight design, the connecting rod big-end bearings are subjected to significant alternating loads. Consequently, the interference–fit interfaces become susceptible to fretting damage, which can markedly shorten engine service life and impair reliability. In the present study, the effects of the big end manufacturing process, bolt preload, and bearing bush interference fit are considered to develop a coupled lubrication–dynamic model of the connecting rod big-end bearing. This model investigates the fretting damage issue in the bearing bush of a marine diesel engine’s connecting rod big end. The results indicate that the relatively low stiffness of the big end is the primary cause of bearing bush fretting damage. Interference fit markedly affects fretting wear on the bush back, whereas the influence of bolt preload is secondary; nevertheless, a decrease in either parameter enlarges the fretting distance. Based on these findings, an optimized design scheme is proposed. Full article
►▼ Show Figures

Figure 1

25 pages, 7172 KiB  
Article
Evaluation of Long-Term Skid Resistance in Granite Manufactured Sand Concrete
by Hongjie Li, Biao Shu, Chenglin Du, Yingming Zhuo, Zongxi Chen, Wentao Zhang, Xiaolong Yang, Yuanfeng Chen and Minqiang Pan
Lubricants 2025, 13(9), 375; https://doi.org/10.3390/lubricants13090375 (registering DOI) - 23 Aug 2025
Abstract
The widespread application of granite manufactured sand (GS) concrete in pavement engineering is limited by issues such as suboptimal particle size distribution and an unclear optimal rock powder content. Furthermore, research on the long-term evolution of the skid resistance characteristics of GS concrete [...] Read more.
The widespread application of granite manufactured sand (GS) concrete in pavement engineering is limited by issues such as suboptimal particle size distribution and an unclear optimal rock powder content. Furthermore, research on the long-term evolution of the skid resistance characteristics of GS concrete remains relatively scarce. This knowledge gap makes it difficult to accurately assess the skid resistance performance of GS concrete in practical engineering applications, thereby compromising traffic safety. To address this research gap, this study utilized a self-developed indoor abrasion tester for pavement concrete to assess the skid resistance of GS concrete. Three-dimensional laser scanning was employed to acquire the concrete’s surface texture parameters. Using the friction coefficient and texture parameters as skid resistance evaluation indicators, and combining these with changes in the concrete’s surface morphology, the study explores how effective sand content, stone powder content, and fine aggregate lithology affect the long-term skid resistance of GS concrete pavements and reveals the evolution trends of their long-term skid resistance. Research results show that as the number of wear cycles increases, low and high effective sand content affect the surface friction coefficient of specimens in opposite ways. Specimens with 95% effective sand content exhibit superior skid resistance. Stone powder content influences the friction coefficient in three distinct variation patterns, showing no clear overall trend. Nevertheless, specimens with 5% stone powder content demonstrate better skid resistance. Among different fine aggregate lithologies, GS yields a higher friction coefficient than river sand (RS), while limestone manufactured sand (LS) shows significant friction coefficient fluctuations across different wear cycles. Adding stone powder substantially enhances mortar strength and delays groove collapse edge formation. Moreover, higher effective sand content and proper stone powder content mitigate bleeding, thereby improving mortar performance. Full article
(This article belongs to the Special Issue Tire/Road Interface and Road Surface Textures)
►▼ Show Figures

Figure 1

16 pages, 4428 KiB  
Article
Toward Coarse and Fine Bimodal Structures for Improving the Plasma Resistance of Al2O3
by Jeong Hyeon Kwon, I Putu Widiantara, Siti Fatimah, Warda Bahanan, Jee-Hyun Kang and Young Gun Ko
Lubricants 2025, 13(9), 374; https://doi.org/10.3390/lubricants13090374 - 22 Aug 2025
Viewed by 30
Abstract
In the quest to produce high-purity alumina, bottom-up engineering via architecting the interior of ceramic with bimodal structures of alumina powders in the absence of any additives has gained considerable attention owing to the simplicity offered. The present work investigated the influence of [...] Read more.
In the quest to produce high-purity alumina, bottom-up engineering via architecting the interior of ceramic with bimodal structures of alumina powders in the absence of any additives has gained considerable attention owing to the simplicity offered. The present work investigated the influence of bimodal structures containing micron (~35 μm) and submicron (~600 nm) Al2O3 powders on the formation of dense Al2O3 ceramic. To this end, ball-milling was conducted to prepare the desired sizes of powders, followed by two-step sintering in a vacuum at 1450 °C and 1650 °C with 6 h and 4 h holding times, consecutively. The bimodal structures induced the formation of Al2O3 ceramic with nearly full densification (>99%; ρ 3.95 g/cm3). Both the coarse and fine-grained moieties synergistically balanced the densification kinetics whilst suppressing abnormal grain growth. The uniform and homogeneous grain size minimized the plasma porosity down to <6.0%, limiting the penetration of plasma during the etching process. Full article
(This article belongs to the Special Issue Tribology in Ball Milling: Theory and Applications)
►▼ Show Figures

Figure 1

29 pages, 5483 KiB  
Review
Advances on Hydrogel Lubrication Modification Under Diverse Design Strategies
by Ying Xu, Youqiang Wang, Kai An, Chenbing Ni, Haiyang Zhang, Yibing Ren and Ziyi Yang
Lubricants 2025, 13(9), 373; https://doi.org/10.3390/lubricants13090373 - 22 Aug 2025
Viewed by 113
Abstract
Hydrogel is a new type of lubricating material, and its lubrication performance is influenced by factors such as water content, chemical structure, cross-linking density, and friction pair materials. Currently, research on the lubrication performance of hydrogels has not formed a unified standard and [...] Read more.
Hydrogel is a new type of lubricating material, and its lubrication performance is influenced by factors such as water content, chemical structure, cross-linking density, and friction pair materials. Currently, research on the lubrication performance of hydrogels has not formed a unified standard and system. Given that the lubricity of hydrogels mainly depends on their components and structure, as well as the chemical interactions between the polymer chains of the hydrogel network and the friction interface, this review systematically discusses the diverse design strategies of hydrogel lubricants based on the hydration and boundary lubrication mechanisms of gels, while elucidating the underlying enhancement mechanisms, as well as the corresponding tribological behavior and applications for different strategies. Finally, the main challenges and future research directions are underlined, aiming to provide theoretical and technical support for the design optimization and practical application of advanced hydrogel lubrication materials. Full article
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-5
Previous Issue
Back to TopTop