scholarly journals An investigation on the tribological behaviors of steel/copper and steel/steel friction pairs via lubrication with a graphene additive

Friction ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 228-238 ◽  
Author(s):  
Junyuan Mao ◽  
Guangyan Chen ◽  
Jun Zhao ◽  
Yongyong He ◽  
Jianbin Luo
Keyword(s):  
Friction And Wear ◽  
Friction Pair ◽  
Lubricant Additive ◽  
Copper Surface ◽  
Transfer Film ◽  
Graphene Sheets ◽  
Tribological Behaviors ◽  
The Coefficient Of Friction ◽  
The Stability ◽  
Copper Transfer

AbstractIn this study, the tribological behaviors of graphene as a lubricant additive for steel/copper and steel/steel friction pairs were compared. For the steel/copper friction pair, the graphene sheets remarkably decreased the coefficient of friction and wear scar depth under low loads, but these slightly increased under high loads. The steel/steel friction pair showed excellent tribological properties even under high loads. Severe plastic deformation on the copper surface reduced the stability of the graphene tribofilm because of a rough copper transfer film on the steel during the running-in period. The results provide a better understanding of the mechanism of graphene as a lubricant additive.

Paper 20: Stability of Self-Generated Oxide Films on Unlubricated En 1A Steel Surfaces

1967 ◽  
Vol 182 (14) ◽  
pp. 167-174
Author(s):  
S. W. E. Earles ◽  
D. G. Powell
Keyword(s):  
Contact Resistance ◽  
Friction And Wear ◽  
Oxide Films ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Bulk Surface ◽  
Surface Breakdown ◽  
The Coefficient Of Friction ◽  
Steel Surfaces ◽  
The Stability

Previous work has shown that within the range 20 < N1/2 U < 600 lbf1,2ft/s friction and wear between unlubricated En 1A steel surfaces is determined primarily by the condition of self-generated oxide films. The stability of these films has been examined using a contact resistance technique and metallurgical examination. At a sliding velocity of 100 ft/s, periodic changes have been observed to occur in the contact resistance between the surfaces. During a cycle the contact resistance increases rapidly at first and then more gradually until a critical value is attained when the film disintegrates. Simultaneous with the surface breakdown there is an increase in the coefficient of friction, pin wear rate, and bulk surface temperature. Conditions are such that rapid re-oxidation occurs, resulting in the formation of a new film A metallurgical examination has shown that even using pin specimens of cold-drawn low carbon steel, subsurface grain re-orientation can be responsible for pearlite-rich layers in the stratified structure produced; hence the hardenability of the substrate, and therefore the support provided for the oxide film, can undergo significant changes as wear proceeds. It is concluded that the unstable nature of self-generated oxide films on steel surfaces is responsible for the periodic increases in friction and wear which have been observed.

scholarly journals Tribological Performance of Nanocomposite Carbon Lubricant Additive

Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 149 ◽  
Author(s):  
Chuanyi Xue ◽  
Shouren Wang ◽  
Daosheng Wen ◽  
Gaoqi Wang ◽  
Yong Wang
Keyword(s):  
Friction And Wear ◽  
Frictional Contact ◽  
Adhesive Wear ◽  
Friction Pair ◽  
Lubricant Additive ◽  
Suspension Stability ◽  
Wear Performance ◽  
Base Oil ◽  
Test Conditions ◽  
Friction And Wear Characteristics

In this research, nanocomposite carbon has been found to have excellent tribological properties as a lubricant additive. To reduce high friction and wear in friction pairs, the modified nanocomposite carbon has been prepared for chemical technology. The morphology and microstructure of the modified nanocomposite carbon were investigated via TEM, SEM, EDS, XPS, and Raman. In this study, varying concentrations (1, 3, and 5 wt. %) within the modified nanocomposite carbon were dispersed at 350 SN lubricant for base oil. The suspension stability of lubricating oils with the modified nanocomposite carbon was determined by ultraviolet-visible light (UV-VIS) spectrophotometry. The friction and wear characteristics of lubricants containing materials of the modified nanocomposite carbon were evaluated under reciprocating test conditions to simulate contact. The morphology and microstructure of the friction pair tribofilms produced during frictional contact were investigated via SEM, EDS, and a 3D surface profiler. The results showed that scratches, pits, grooves, and adhesive wear were significantly reduced on the surface of the friction pair which was used with 3% nanocomposite carbon lubricant. Additionally, the modified nanocomposite carbon showed excellent friction reducing and anti-wear performance, with great potential for the application of anti-wear.

Conductive capacity and tribological properties of several carbon materials in conductive greases

2016 ◽  
Vol 68 (5) ◽  
pp. 577-585 ◽  
Author(s):  
Zhengfeng Cao ◽  
Yanqiu Xia ◽  
Xiangyu Ge
Keyword(s):  
Electron Microscope ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Volume Resistivity ◽  
Lubricant Additive ◽  
Step Method ◽  
Content Type ◽  
X Ray ◽  
The Coefficient Of Friction ◽  
Complex Lithium

Purpose The purpose of this paper is to synthesize a new kind of conductive grease which possesses a prominent conductive capacity and good tribological properties. Design/methodology/approach A two-step method was used to prepare complex lithium-based grease. Ketjen black (KB), acetylene black (AB) and carbon black (CB) were characterized by transmission electron microscope and used as lubricant additives to prepare conductive greases. Conductive capacity was evaluated by a conductivity meter, a surface volume resistivity meter and a circuit resistance meter. Tribological properties were investigated by a reciprocating friction and wear tester (MFT-R4000). The worn surfaces were analyzed by a scanning electron microscope, Raman spectroscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscope. Findings The conductive grease prepared with KB has a prominent conductive capacity at room temperature, 100°C and 150°C. Further, this conductive grease also possesses better tribological properties than AB and KB greases. When the concentration of KB is 1.8 Wt.%, the coefficient of friction and wear width reduced by 11 and 14 per cent, respectively. Originality/value This work is a new application of nanometer KB as a lubricant additive in grease, which provides a direction for preparing conductive grease. The conductivity and tribology experiments have been carried out though the variation of experiment conductions.

Influence of Nano-Serpentine on Tribological Behaviors and Wear Process of Hybrid PTFE/Kevlar Fabric Composites

2011 ◽  
Vol 418-420 ◽  
pp. 455-459 ◽  
Author(s):  
Ling Lu ◽  
Yu Lin Yang ◽  
Xiao Wen Qi ◽  
Zong Xiang Hou
Keyword(s):  
Laser Scanning ◽  
Friction And Wear ◽  
Confocal Laser Scanning Microscope ◽  
Transfer Film ◽  
Confocal Laser ◽  
Wear Process ◽  
Tribological Behaviors ◽  
Fabric Composite ◽  
Fabric Composites ◽  
Worn Surface

Tribological behaviors and wear process of the unfilled and 2% nano-serpentine filled polymer-based hybrid PTFE/Kevlar fabric composites were evaluated on a MMU-5G friction and wear tester. The variation of the morphologies of the worn surface and the morphologies of transfer film during the wear processes of the two composites were observed and analyzed by means of the confocal laser scanning microscope (CLSM). The results show that the addition of nano-serpentine can effectively slow down the wear process and obviously improve the wear resistance of the hybrid PTFE/Kevlar fabric composite, meanwhile the friction property was ameliorative. That probably because the nano-serpentine does not only have the admirable tribological performance, but also have excellent surface activity, which improved the formation of the self-lubricating transfer film.

Tribological evaluation of piston ring/cylinder liner assembly in automotive engines using GNP as a lubricant additive

2021 ◽  
pp. 095440622110553
Author(s):  
Gurtej Singh ◽  
Mohammad Farooq Wani ◽  
Mohammad Marouf Wani
Keyword(s):  
Wear Rate ◽  
Friction And Wear ◽  
Piston Ring ◽  
Film Formation ◽  
Cylinder Liner ◽  
Lubricant Additive ◽  
Operating Conditions ◽  
Power Losses ◽  
Automotive Engines ◽  
The Coefficient Of Friction

Friction and wear are the main causes of energy dissipation in automotive engines. To minimize the frictional power losses, it is extremely important to improve the tribological characteristics of ring/liner assembly which accounts for almost 40–50% frictional power losses. The present study attempts to mitigate friction and wear of the ring/liner tribo-pair using GNP/SAE 15W40 nano-lubricant. To simulate the ring/liner interface, the tribological performance of nano-lubricants was assessed using a tribometer based on ASTMG181 standard under various operating conditions. The coefficient of friction (COF) and wear rate lowered using graphene nano-lubricants (GNL). The tribological results showed that friction coefficient, wear rate, and surface roughness of piston ring improved in the range 17.71%–42.33%, 25%–40.62%, and 61%, respectively, under GNL lubricating conditions during the boundary lubrication. Further, the characterization of wear tracks of piston ring and cylinder liner confirmed tribo-film formation on worn surfaces resulting in decreased COF and wear rate.

scholarly journals Modified graphene as novel lubricating additive with high dispersion stability in oil

Friction ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 143-154 ◽  
Author(s):  
Pu Wu ◽  
Xinchun Chen ◽  
Chenhui Zhang ◽  
Jiping Zhang ◽  
Jianbin Luo ◽  
...  
Keyword(s):  
Friction And Wear ◽  
Wear Track ◽  
Normal Load ◽  
Lubricant Additive ◽  
Tribological Performance ◽  
Dispersion Stability ◽  
High Dispersion ◽  
Base Oil ◽  
The Coefficient Of Friction ◽  
Modified Graphene

Abstract Graphene is a promising material as a lubricant additive for reducing friction and wear. Here, a dispersing method which combines chemical modification of graphene by octadecylamine and dicyclohexylcarbodiimide with a kind of effective dispersant has been successfully developed to achieve the remarkable dispersion stability of graphene in base oil. The stable dispersion time of modified graphene (0.5 wt%) with dispersant (1 wt%) in PAO-6 could be up to about 120 days, which was the longest time reported so far. At the same time, the lubricant exhibits a significant improvement of tribological performance for a steel ball to plate tribo-system with a normal load of 2 N. The coefficient of friction between sliding surfaces was ~0.10 and the depth of wear track on plate was ~21 nm, which decreased by about 44% and 90% when compared to pure PAO-6, respectively. Furthermore, the analysis of the lubricating mechanisms in regard to the sliding-induced formation of nanostructured tribo-film has been contacted by using Raman spectra and TEM.

Friction and Wear Performance of the New Ceramic Anti-Wear Agent Containing N-B-Mo under Various Loads

2020 ◽  
Vol 1001 ◽  
pp. 169-174
Author(s):  
Xu Guo Huai ◽  
Xiao Wei Fan
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Friction And Wear ◽  
Friction Pair ◽  
Optical Microscope ◽  
Lubricating Oil ◽  
Wear Property ◽  
X Ray Diffraction ◽  
The Coefficient Of Friction ◽  
Lubricating Property

The friction and wear experiment employed M-2000 friction and wear tester which friction pair made up of Q235//GCr15 steel, and lubricating oil which contains 3% new N-B-Mo ceramic anti-wear agent was adopted as the medium. The effect of content of new ceramic anti-wear agent on friction and wear property was investigated by using X-Ray diffraction (XRD), optical microscope (OM), et al, and the mechanism of ceramic anti-wear agent was also analyzed. The results showed that in the range of 50-300N load, the friction coefficient is basically related to the size of the load, and the greater the load, the greater the coefficient of friction, the size of the wear rate is not simply increased as the load increases. The wear rate was lowest when the load was 200N. Under this load, the new N-B-Mo ceramic anti-wear agent was generated BN phase which has self-lubricating property at worn surface, reduce the friction coefficient of Q235//GCr15 friction pair and the wear rate of Q235 steel, plays an anti-friction and anti-wear role.

Using recurrence plots for stability analysis of ring-on-disc tribopairs

2019 ◽  
Vol 71 (4) ◽  
pp. 532-539
Author(s):  
Guodong Sun ◽  
Hua Zhu ◽  
Cong Ding
Keyword(s):  
Recurrence Plots ◽  
Friction Process ◽  
Content Type ◽  
Tribological Behaviors ◽  
Aisi 52100 ◽  
The Coefficient Of Friction ◽  
Aisi 1045 ◽  
Quantification Analysis ◽  
Evolution Laws ◽  
The Stability

Purpose AISI 52100-AISI 1045 specimens were used as the ring-on-disc tribopairs in the experiments to investigate the stability of friction process. Design/methodology/approach The coefficient of friction (COF) signals were measured throughout the friction process and the recurrence plots (RPs) and recurrence quantification analysis (RQA) are adapted to analyze the stability of the tribosystem. Findings The results show that the COF time-series acquired from different tests possess the same dynamic evolution laws. The evolution of RPs follows the rules of “disrupted-homogeneous-disrupted,” which corresponds to the “running-in, steady-state and increasing stages” of friction process. Additionally, the evolution laws of RQA measures LAM, Vmax and TT accord with the “bathtub curve.” Therefore, both RPs and RQA measures can inform quantitative interpretations of tribological behaviors and friction process identification. Originality/value The both RPs and RQA are capable of characterizing the tribological behaviors and can depict the various stages of friction process.

TRIBOLOGICAL PERFORMANCE OF MODIFIED FLOCCULENT GRAPHITE AS LUBRICANT ADDITIVES

2019 ◽  
Vol 27 (02) ◽  
pp. 1950108
Author(s):  
CHUAN YI XUE ◽  
SHOU REN WANG ◽  
JIN FENG LENG ◽  
YONG WANG ◽  
GAO QI WANG
Keyword(s):  
Friction And Wear ◽  
Piston Ring ◽  
Gasoline Engine ◽  
Adhesive Wear ◽  
Friction Pair ◽  
Cylinder Liner ◽  
Lubricant Additive ◽  
Suspension Stability ◽  
Wear Performance ◽  
Friction And Wear Characteristics

In this research, graphite has been found to have excellent tribological properties as a lubricant additive. To reduce high friction and wear in cylinder liner piston ring friction pairs, modified flocculent graphite have been prepared via chemical technology. The morphology and microstructure of modified flocculent graphite were investigated via SEM, EDS, XRD and IR. In this study, varying concentrations (0.1, 0.5, and 0.9 wt.%) within modified flocculent graphite were dispersed at 350 SN lubricant for Gasoline Engine. Suspension stability of the lubricating oils with modified flocculent graphite and graphite as determined by ultraviolet-visible light (UV-VIS) spectrophotometry. The friction and wear characteristics of lubricants containing materials of modified flocculent graphite were evaluated under reciprocating test conditions to simulate contact. The morphology and microstructure of the friction pair tribofilms produced during frictional contact were investigated via SEM, EDS and a 3D surface profiler. The results show that scratching, pits, furrows and adhesive wear took place, respectively, on the worn surfaces of friction pairs. But, modified flocculent graphite showed excellent friction reducing and anti-wear performance and subsequently has great potential for the application of anti-wear.

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