Article
Engineering, Mechanical
Junqin Shi, Meng Zhang, Jianxi Liu, Guoqiang Liu, Feng Zhou
Summary: The study found that with the increase of surface coverage and contact pressure, R-OH formed a dense monolayer, while R-NH2 formed a loose adsorption layer that transformed into a compact layer with increased pressure. Additionally, high pressure benefits OFM adsorption, and high surface coverage enhances the anti-pressure ability of adsorption layers.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Chemistry, Physical
Junqin Shi, Hang Li, Yang Lu, Lin Sun, Shaofeng Xu, Xiaoli Fan
Summary: The synergistic effect of organic friction modifiers (OFMs) consisting of glycerol monolaurate (GML) and tri-n-octylamine (N888) in base oil was studied using molecular dynamics simulations. The results showed that N888 molecules interspersed among GML molecules to form an intercoordination adsorption film. The system with a ratio of 3:1 of GML to N888 exhibited the best synergistic lubrication with the lowest friction coefficient. Chemisorption of GML molecules on the Fe2O3 surface was confirmed by density function theory. High shear velocity led to the breakage of the adsorption film and increased friction, while contact pressure helped reduce friction. The synergistic lubrication was attributed to the interface slip between the base oil and OFM films, rather than the interlaminar shear caused by an imbalanced combination or high shear velocity.
APPLIED SURFACE SCIENCE
(2023)
Article
Engineering, Mechanical
Febin Cyriac, Tee Xin Yi, Sendhil K. Poornachary, Pui Shan Chow
Summary: This study investigated the impact of organic friction modifiers and ZDDP on boundary lubrication of steel surfaces, finding that PFMs are generally more effective than OFMs in eliminating the boundary regime. Both OFMs and PFMs had a negative effect on the anti-wear performance of ZDDP, possibly due to preferential adsorption or decomposition products.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
Jinchi Hou, Masaki Tsukamoto, Seanghai Hor, Xingyu Chen, Juntao Yang, Hedong Zhang, Nobuaki Koga, Koji Yasuda, Kenji Fukuzawa, Shintaro Itoh, Naoki Azuma
Summary: High-performance organic friction modifiers (OFMs) are crucial for reducing energy loss and carbon footprint. A new class of OFMs called C(12)Amide-TEMPO was investigated in this study, and it showed superior performance in load-carrying capacity, wear reduction, and stability of friction compared to conventional OFMs. The amide group played a critical role in these properties.
Review
Engineering, Mechanical
R. Arizal Firmansyah, R. Y. Perry Burhan, Yulfi Zetra, Didik Prasetyoko
Summary: This paper focuses on the application of bio-additives in fossil diesel and their impact on lubricity. Researchers need to address various challenges in order to develop better bio-additives. The paper also discusses the synthesis methods and lubricity testing methods of bio-additives, and highlights the challenges and future research directions in developing lubricity bio-additives.
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2022)
Article
Engineering, Mechanical
R. Taylor, I Sherrington
Summary: A new equation is proposed to calculate the proportion of mixed/boundary friction in a contact based on experimental data, and it is revealed that some commonly used rough surface contact models underestimate this type of friction. The new model suggests treating rough surface contact modeling as a growth/decay process, and the consequences of this approach are discussed.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Chemistry, Physical
Ivan Lobzenko, Yoshinori Shiihara, Yoshitaka Umeno, Yoshikazu Todaka
Summary: Nanocrystallization processes can enhance the tribological properties of metallic surfaces under boundary lubrication conditions. Adsorption of fatty lubricant molecules on a nanostructured iron surface was found to be stronger near grain boundaries, as revealed by first-principles calculations.
APPLIED SURFACE SCIENCE
(2021)
Article
Engineering, Mechanical
Jinchi Hou, Masaki Tsukamoto, Hedong Zhang, Kenji Fukuzawa, Shintaro Itoh, Naoki Azuma
Summary: The nanoscale frictional properties of conventional and recently developed TEMPO-based OFMs were studied, and their characteristics were explained using the Eyring activation energy model. This study contributes to the development of high-performance OFMs.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Nanoscience & Nanotechnology
Ming Jun Lee, Rosa M. Espinosa-Marzal
Summary: Double-network (DN) hydrogels consisting of physically and chemically crosslinked networks show biocompatibility and high strength. This work explores the microstructure and properties of a DN hydrogel composed of agarose as the first network and a copolymer as the second network. By imaging and studying frictional response, the researchers reveal the role of the networks and charge in lubrication. They also demonstrate the dynamic control of interfacial properties and its implications for soft robotics and tissue replacements.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Akepati Bhaskar Reddy, Bulat Munavirov, Georgia A. Pilkington, Gabriel Calderon Salmeron, Mark W. Rutland, Sergei Glavatskih
Summary: The study revealed that higher dissociation of orthoborate ILs in biodegradable oil allows the formation of stable ionic boundary films, reducing friction and providing better wear protection; while phosphate and phosphinate ILs exhibit lower dissociation in biodegradable oil, resulting in increased friction and more severe wear.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2021)
Article
Energy & Fuels
Frank T. Hong, Eshan Singh, S. Mani Sarathy
Summary: The study found that adding ethanol to diesel fuel increases wear rates, leading to reduced lubricity. As ethanol content increases, there are more metal-to-metal contacts and thinner fuel films.
Review
Chemistry, Physical
Changzhi Zhou, Zhangpeng Li, Shuwen Liu, Tianrong Zhan, Wenqiang Li, Jinqing Wang
Summary: Layered double hydroxide (LDH) has great potential in the field of lubrication due to its unique structure and adjustable properties. This review presents various methods to improve the anti-friction, anti-wear, and lubrication performance of LDH materials, and summarizes the specific applications of LDH in different lubrication scenarios.
APPLIED CLAY SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Zhe Chen, Seong H. Kim
Summary: It has been discovered that nanoscale super-lubricity between amorphous silica tip and graphite basal plane can be tuned by physisorbing various molecules. This finding enables on-demand control of friction.
APPLIED MATERIALS TODAY
(2022)
Article
Engineering, Mechanical
J. Umer, N. J. Morris, R. Rahmani, H. Rahnejat, S. Howell-Smith, S. Balakrishnan
Summary: This paper presents an experimental case study of a new generation of fully formulated engine lubricants, focusing on the key interactions and frictional behavior of the dispersant and friction modifiers at different operating temperatures.
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2021)
Article
Engineering, Chemical
Aaron L. Barnes, Ardian Morina, Rhiann E. Andrew, Anne Neville
Summary: This study compared the characteristics of tribofilms formed by three different sulfur additives, revealing a sparser distribution of MoS2 for molybdate ester. While no crystalline molybdenum oxides were observed in Raman spectroscopy, their presence was inferred through XPS analysis; the chemical nature of the films formed by different additives is likely similar.
Article
Engineering, Mechanical
Busra Duran, Jerome Cavoret, David Philippon, Fabrice Ville, Arnaud Ruellan, Frank Berens
Summary: This study analyzes the changes in the physicochemical properties and tribological performances of gear transmission oils during field operation, finding differences from traditional engine oils.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Baocheng Liu, Hongsheng Chen, Jun Zhou, Jing Wang, Wenxian Wang, Xiaochun Chen, Sanxiao Xi
Summary: This study used fast hot pressing sintering to fabricate WC/AlCoCrFeNi2.1 metal matrix composites (MMCs). It was found that the addition of reinforced particles increased the microhardness, nanoindentation and wear resistance of the MMCs. During frictional processes, an oxide film formed, providing material protection, enhancing stability and reducing friction-induced losses.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Pradip Kumar Verma, Alok Singh
Summary: This study investigates the mechanical properties and wear resistance of CoMoMnNiV high entropy alloy reinforced aluminium matrix composite processed through stir-squeeze casting assisted with an ultrasonic transducer. The results show significant improvements in mechanical properties and wear resistance, with the composite containing 8 wt% HEA demonstrating the highest resistance to wear. Optical microscopy, SEM, and an optical profilometer were used for a thorough examination of the microstructure and worn surface.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Zhenghai Yang, Yingjian Song, Jinlong Jiao, Wenbo Li, Bao Shangguan, Yongzhen Zhang
Summary: This study investigated the friction, wear properties, and current-carrying properties of copper-graphite composites paired with brass C28000. The results showed that the current-carrying properties of the composite materials were excellent, but their wear rate was the main limiting factor. Furthermore, an increase in the thickness of the graphite layer led to an improvement in the uniformity of damage.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Moustafa Mahmoud Yousry Zaghloul, Karen Steel, Martin Veidt, Michael T. Heitzmann
Summary: This research evaluates and compares the impact of different material types on the tribological characteristics of Polyamide 6 composites, and finds that glass fiber-reinforced Polyamide 6 exhibits better friction and wear performance under high-pressure velocity factors.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Shaoqing Qin, Lida Zhu
Summary: In this paper, the surface and subsurface damage of laser assisted grinding CrCoNi medium entropy alloys were investigated using molecular dynamics simulations. The results showed that the application of laser energy can reduce cutting forces and minimize subsurface damage.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Kaikui Zheng, Youxi Lin, Tingzheng Lai, Chenghui Gao, Ming Liu, Zhiying Ren
Summary: The study investigated the use of waste foundry resin-bonded sand as a substitute for copper in resin-based brake material. It found that the waste sand was more favorable for improving the overall friction and wear properties of the material compared to copper. Waste sand benefited the material by forming a friction layer, leading to increased friction coefficient and stability. Brake material with 10-15% waste sand showed excellent heat-fade resistance.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Dayang Li, Fanhao Zhou, Yutong Gao, Kun Yang, Huimin Gao
Summary: This article introduces a continuous prediction model based on deep learning for predicting the power output of steam turbines. The model uses long short term memory (LSTM) method to develop a trend prediction model and optimizes the prediction model through feature selection method. Experimental results show that the model outperforms other models in terms of prediction performance.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Tomohiro Toyoda, Ryo Yasuike, Toshihiro Noda
Summary: In this study, a elasto-plastic constitutive model of friction incorporating the concept of superloading surface was developed based on the subloading friction model. The proposed model achieves a smooth transition of friction by describing the evolution rule of structure, treating the state with static friction coefficient larger than kinetic friction coefficient as the bulkiness of structure. The positive definiteness of the plastic multiplier, loading condition, and material parameters were derived, and the validity of the proposed model in accordance with the subloading-friction model was confirmed through a stick-slip simulation of a mass-spring system.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
P. Balaji, B. Surya Rajan, K. Sathickbasha, P. Baskara Sethupathi, Deviga Magadevan
Summary: This study emphasizes the importance of using a variety of solid lubricants with different oxidation temperature regimes to enhance the tribological performance of brake pads.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Jian Ma, Yancong Liu, Javad Mostaghimi, Na Zhang
Summary: This paper investigates the influence of preparation strategies on the lubrication properties of surface textures. Three laser scanning strategies are proposed to achieve a sinusoidal textured surface, and the evolution of surface structure and chemical composition is discussed. The findings show that ridge structures enhance anti-wear properties but also increase the friction coefficient. However, the oil cover preparation method prevents the formation of ridges and improves wettability.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Mohammad Roostaei, Arvin Taghizadeh Tabrizi, Hossein Aghajani
Summary: In this research, the Al2O3/MoS2 nanocomposite coating layer was successfully applied on the surface of Ti-6Al-4 V alloy. The relation between the surface characteristics and wear resistance of the coating was studied using atomic force microscopy analysis and pin-on-disk wear test method. The results showed that the nanocomposite coating significantly reduced the wear rate and provided an equation to calculate the Lancaster coefficient.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Musa Bilgin, Sener Karabulut, Halil Karakoc, Yunus Kayir, Murat Sarikaya
Summary: This study investigates various methods to improve the machinability efficiency of Inconel 718 alloy while considering their effect on microstructural properties. The results show that hot+PMQL, hot+SiCNMQL, and hot+Al2O3-NMQL contribute significantly to the improvement of machinability characteristics. The EBSD analysis also reveals that a limited area is affected by heat in the hot machining environment and that the removal of the heated layer during milling process helps preserve the microstructure.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Q. Gao, Y. Fan, Y. G. Wu, J. L. Liu, J. Wang, L. Li
Summary: Fretting wear significantly affects the hysteresis behavior of the contact surface and leads to joint degradation. This study investigates the influence of harmonic normal force on the evolution of interface morphology and contact parameters with fretting wear. The results show that the harmonic normal force can significantly influence the hysteresis loop and the energy dissipation distribution on the contact surface.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Benjamin Weiland, Floriane Leclinche, Anis Kaci, Brigitte Camillieri, Betty Lemaire-Semail, Marie -Ange Bueno
Summary: This study presents a systematic approach to generating control signals for a tactile simulator that simulate the touch of textile fabrics. By using a friction modulation tactile surface and acquiring forces from real surfaces with artificial finger mimicking fingerprints, control signals are generated and processed in the frequency domain before sending them to the tactile stimulator. The study focuses on the potential benefits of incorporating fingerprint information in fabric simulations to achieve a more realistic tactile perception. A sensory analysis with 36 participants using the generated control signals showed better discrimination without fingerprint information.
TRIBOLOGY INTERNATIONAL
(2024)