Tribological properties of metallic nanoparticles as lubricant additives under the applied electric currents

2018 ◽  
Vol 70 (9) ◽  
pp. 1714-1720 ◽  
Author(s):  
Lina Si ◽  
Yan Pan ◽  
Xiaoqing Zhang ◽  
Jie Wang ◽  
Jia Yao ◽  
...  
Keyword(s):  
Tribological Properties ◽  
Metallic Nanoparticles ◽  
Contact Region ◽  
Tribological Performance ◽  
Lubricant Additives ◽  
Wear Properties ◽  
Electric Currents ◽  
Ag Nps ◽  
Content Type ◽  
Electric Contacts

Purpose This paper aims to clarify the effects of metallic nanoparticles (NPs) additives and room temperature ionic liquids (ILs) on the tribological performance of electric contacts. Design/methodology/approach Tribological properties of copper (Cu) and silver (Ag) NPs as lubricant additives in different lubricants of ILs or polyalphaolefin (PAO) oils under applied electric currents were investigated. After tribological tests, morphologies of worn surfaces were observed; meanwhile, lubrication and anti-wear properties were analyzed. Findings The mixture solution of the IL and Cu NPs showed desirable lubrication and anti-wear properties due to the reduction of electrocorrosion and the enhancement of rolling effects of particles in the contact region. The anti-wear performance of Cu NPs is better than that of Ag NPs due to the difference in the particle size. The PAO oil with the Cu NPs additives showed poor lubrication properties due to the low solubility of the particles in the oil. When the direction of applied current was changed, the friction of the lubricant with better conductivity was more stable in the variation trend. Originality/value This paper begins with a study of tribological properties of Cu and Ag NPs as lubricant additives in different lubricants of IL or PAO oils under applied electric currents. The authors then propose several methods and possible solutions which could be implemented to improve the tribological performance of electric contacts.

Preparation and tribological properties of Ag nanoparticles/reduced graphene oxide nanocomposites

2018 ◽  
Vol 70 (9) ◽  
pp. 1684-1691 ◽  
Author(s):  
Leihua Xu ◽  
Yong Zhang ◽  
Dekun Zhang ◽  
Mei Leng
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Tribological Properties ◽  
Ag Nanoparticles ◽  
Lubricant Film ◽  
Wear Properties ◽  
Ag Nps ◽  
Content Type ◽  
Lubricant Oil ◽  
Reduced Graphene

Purpose This paper aims to report the tribological behavior of Ag nanoparticles/reduced graphene oxide nanocomposites (Ag/RGO NCs) and Ag nanoparticles (Ag NPs) as a green additive in oil with different concentration and under different friction conditions. Design/methodology/approach The Ag/RGO NCs and Ag NPs were both synthesized in a chemical reduction method. The diameter of silver nanoparticles implanted between RGO sheets was about 25 nm and that of silver sol was 70 nm. The morphology and structure of Ag/RGO NC were characterized by TEM, XRD and FTIR. The tribological properties of Ag/RGO NCs and Ag NPs as lubricant oil additive were evaluated by measuring the friction coefficients and wear of the surface in different condition which were tested on UMT-II. Findings The results indicated that both the additives improved the friction-reduced and anti-wear properties of paraffin oil, and Ag/RGO NCs has better tribological performance than Ag NPs. The excellent tribological properties were attributed to the special structure of Ag/RGO NC and the formation of tribofilm reducing the friction and wear on the shearing surfaces. Research limitations/implications It is relatively difficult to observe the morphology of the lubricant film formed on the friction surface and to analyze the chemical composition at different depths of the lubricant film. Originality/value It is the first time for Ag/RGO NCs to be applied to improve the friction-reduced and anti-wear properties of lubricant oil as additive.

scholarly journals Tribological performance of various metal-doped carbon dots as water-based lubricant additives and their potential application as additives of poly(ethylene glycol)

Friction ◽  
2021 ◽  
Author(s):  
Weiwei Tang ◽  
Xuejun Zhu ◽  
Yufeng Li
Keyword(s):  
Ethylene Glycol ◽  
Tribological Properties ◽  
Carbon Dots ◽  
Lubricant Additives ◽  
Poly Ethylene Glycol ◽  
Wear Properties ◽  
Water Based ◽  
Friction Reducing ◽  
Poly Ethylene ◽  
Metal Doped

AbstractAdvances in nano-lubricant additives are vital to the pursuit of energy efficiency and sustainable development. Carbon dots (CDs) have been widely investigated in the domain of lubricant additives owing to their extraordinary tribological properties, in particular, their friction-reducing and anti-wear properties. Metal-doped CDs are a new type of CDs, and their friction-reducing and anti-wear properties are attracting increasing attention. Therefore, a series of CDs doped with various divalent metal ions have been successfully synthesized via one-pot pyrolysis. The tribological properties of the synthesized CDs as water-based lubricant additives are in the following order: Zn-CDs > Cu-CDs ≫ Mg-CDs > Fe-CDs > U-CDs. Specifically, adding 1.0 wt% of Zn-CDs into water-based lubricant results in 62.5% friction and 81.8% wear reduction. Meanwhile, the load-carrying capacity of the water-based lubricant increases from 120 N to at least 500 N. Zn-CDs as an additive have long service life. Additionally, anion-tuned Zn-CDs fabricated via anion exchange exhibit promise as lubricant additives for poly(ethylene glycol). Based on the results of wear scar surface analyses, it is discovered that tribochemical films, primarily composed of iron oxides, nitrides, metal carbonates, zinc oxides, zinc carbonates, organic compounds, and embedded carbon cores, formed on the rubbing surfaces with a thickness of approximately 270 nm when Zn-CDs are used as additives. This film combined with the “ball-bearing” and third-particle effects of Zn-CDs contributed to excellent lubrication performance.

Tribological properties of the epoxy resin-based solid lubricant coating modified by Kevlar fibers

2018 ◽  
Vol 70 (9) ◽  
pp. 1706-1713 ◽  
Author(s):  
Guotao Zhang ◽  
Yanguo Yin ◽  
Ting Xie ◽  
Dan Li ◽  
Ming Xu ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Epoxy Resin ◽  
Tribological Properties ◽  
Dry Friction ◽  
Friction And Wear ◽  
Solid Lubricant ◽  
Transfer Film ◽  
Wear Properties ◽  
Content Type ◽  
Friction And Wear Properties

Purpose This paper aims to obtain high mechanical and good tribological properties of epoxy resin-based coatings under dry friction conditions. Design/methodology/approach Bonded solid lubricant coatings containing Kevlar fibres were prepared by a spraying method. The friction and wear properties of the coatings were experimentally investigated with a face-to-face tribometre under dry friction conditions. Scanning electron microscopy, energy dispersive X-ray spectroscopy and 3D laser scanning technologies were used to characterise the tribological properties. The action mechanism of the Kevlar fibres on a solid lubricant transfer film was also analysed. Findings Adding Kevlar fibres can significantly improve the wear resistance of the coatings. When the Kevlar fibre content increases, the tribological properties of the coatings improve and then worsen. Superior properties are obtained with 0.03 g of Kevlar fibres. Appropriately increasing the load or speed is beneficial to the removal of the outer epoxy resin and the formation of a lubricant film. During friction, the solid lubricants wrapped in the epoxy resin accumulate on the surface to form a transfer film that shows a good self-lubricating performance. In the later friction stage, fatigue cracks occur on the solid lubricant film but cannot connect to one another because of the high wear resistance and the entanglement of the rod-like Kevlar fibres. Thus, no large-area film falls from the matrix, thereby ensuring the long-term functioning of solid lubricant coatings. Originality/value Epoxy resin-based solid lubricant coatings modified by Kevlar fibres were prepared, and their friction and wear properties were investigated. Their tribological mechanisms were also proposed. This work provided a basis for the analysis of the tribological properties and design of bonded solid lubricant coatings containing Kevlar fibres.

BPNN-QSTR Models for Triazine Derivatives for Lubricant Additives

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Tingting Wang ◽  
Zhan Wang ◽  
Hao Chen ◽  
Kang Dai ◽  
Xinlei Gao
Keyword(s):  
Tribological Properties ◽  
Back Propagation ◽  
Three Dimensional ◽  
Predictive Ability ◽  
Quantitative Relationship ◽  
Molecular Structures ◽  
Lubricant Additives ◽  
Extreme Pressure ◽  
Wear Properties ◽  
Triazine Derivatives

Abstract Triazine derivatives are a kind of lubricant additives with excellent tribological properties. It is of great significance to study the quantitative relationship between their chemical structure and tribological properties. In the present study, the quantitative structure tribo-ability relationships (QSTR) between 20 triazine derivatives and their respective extreme-pressure properties as lubricant additives were analyzed by the back propagation neural network (BPNN) method. The BPNN-QSTR model had satisfactory stability and predictive ability (R2 = 0.9965, R2(LOO) = 0.9195, q2 = 0.8274). The anti-wear model also yielded good predictions (R2 = 0.9757, R2(LOO) = 0.6261, q2 = 0.8022). Two- and three-dimensional structural descriptors were used to analyze molecular structures that affected extreme-pressure and anti-wear properties. The results indicate that the three-dimensional molecular dimensions and the bonding modes of the skeleton atoms in the molecules were important factors. In addition, the effects of N, P, O, and other hetero-atoms on the tribological properties were reflected in their corresponding group types and electronic structures.

Effect of preparation process on elevated temperature tribological properties of composite polyurea grease

2016 ◽  
Vol 68 (5) ◽  
pp. 611-616 ◽  
Author(s):  
Zujian Shen ◽  
Fei Geng ◽  
Xinxin Fan ◽  
Zhichen Shen ◽  
Haiyan Wang
Keyword(s):  
Thermal Stability ◽  
Elevated Temperature ◽  
Tribological Properties ◽  
Water Resistance ◽  
Physical Method ◽  
Heat Stability ◽  
Wear Properties ◽  
Excellent Thermal Stability ◽  
Content Type ◽  
Polyurea Grease

Purpose This paper aims to investigate and prepare the composite polyurea greases with excellent thermal stability and tribological properties. Design/methodology/approach In this paper, composite Ba-based (Ba, barium) tetra-polyurea lubricating greases were prepared with two different methods: mixing Ba-based gelatinizer and tetra-polyurea gelatinizer by a physical method; and introducing barium carboxylate into tetra-polyurea molecules by a chemical method. The properties of the products, such as heat stability, water resistance and friction performance, were analyzed with thermogravimetry, water-resistance test and four-ball friction test. Findings The results indicated that the products obtained by chemically introducing barium carboxylate into tetra-urea molecules showed better elevated temperature tribological properties, and the disadvantages of the polyurea greases with high temperature hardening were also obviously improved. The cone penetration rate at 180°C for 24 h is only 3 per cent. The friction coefficient can be decreased to 0.44 and the last non-seizure load value was increased from 560 N to 1,120 N without any other additives. Originality/value The research is significant because the prepared composite grease showed excellent performances, such as the outstanding thermal stability, water resistance and excellent extreme pressure and anti-wear properties, which may be widely applied in steel, metallurgy, bearings and other industrial fields.

Tribological Properties of the Overbased Calcium Sulfonate Complex Greases Containing Different Lubricant Additives

2013 ◽  
Vol 645 ◽  
pp. 133-136
Author(s):  
Peng Qiao ◽  
Yan Qiu Xia ◽  
Xiang Yu Ge
Keyword(s):  
Ionic Liquid ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Sliding Friction ◽  
Tribological Performance ◽  
Mining Equipment ◽  
Wear Properties ◽  
Friction Tester ◽  
Calcium Sulfonate ◽  
Friction And Wear Properties

Overbased calcium sulfonate complex greases have excellent friction and wear properties and have been widely used in metallurgy and mining equipment. The effects and tribological performance of molybdenum dialkydithiocarbamate (MoDTC) and ionic liquid 1-(2-hydroxyethyl)-3-methylimidazolium bis (trifluoromethylsulfonyl) imide ([C2OHMim][NTf2]), 1-(2-hydroxyethyl)-3-hexylimidazolium bis (trifluoromethylsulfonyl) imide ([C2OHHim][NTf2s]), added in overbased calcium sulfonate complex grease as additives were investigated by using reciprocating ball-on-disk sliding friction tester. The results showed that the two kinds of additives with a certain range of concentration could improve the tribological properties of greases.

The Effect of PTFE on the Mechanical and Friction and Wear Properties of GF/PA6 Composites

2011 ◽  
Vol 284-286 ◽  
pp. 2370-2373 ◽  
Author(s):  
Jian Li
Keyword(s):  
Glass Fiber ◽  
Tensile Properties ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Polyamide 6 ◽  
Tribological Performance ◽  
Main Role ◽  
Wear Properties ◽  
Glass Fiber Reinforced ◽  
Friction And Wear Properties

The effects of PTFE on the tensile and tribological properties of glass fiber reinforced polyamide 6(PA6) composites were studied. Tribological tests were conducted on an M2000 friction and wear tester using a block-on-ring arrangement. It was observed that the PTFE played a main role in the tensile-resistant and wear-resistant properties of the PA6 composites. The tensile properties were ruled by the fiber–matrix adhesion. And the excellent tribological performance of the PTFE fillers improved the tribological properties of PA6 composites.

Synthesis and tribological properties of oil-soluble copper nanoparticles as environmentally friendly lubricating oil additives

2015 ◽  
Vol 67 (3) ◽  
pp. 227-232 ◽  
Author(s):  
Yujuan Zhang ◽  
Yaohua Xu ◽  
Yuangbin Yang ◽  
Shengmao Zhang ◽  
Pingyu Zhang ◽  
...  
Keyword(s):  
Tribological Properties ◽  
Liquid Paraffin ◽  
Lubricating Oil ◽  
Infrared Spectrometry ◽  
Cu Nanoparticles ◽  
Wear Properties ◽  
Environment Friendly ◽  
Content Type ◽  
Oil Additives ◽  
Lubricating Oil Additives

Purpose – The purpose of this paper is to synthesize oil-soluble copper (Cu) nanoparticles modified with free phosphorus and sulfur modifier and investigate its tribological properties as environment-friendly lubricating oil additives. Design/methodology/approach – To improve the anti-oxidation properties of these nanoparticles, two kinds of surface modifiers, oleic acid and oleylamine were used simultaneously. The morphology, composition, structure and thermal properties of as-synthesized Cu nanoparticles were investigated by means of transmission electron microscopy, X-ray powder diffraction, Fourier transform infrared spectrometry and differential thermal and thermogravimetric analysis. The tribological properties of as-synthesized Cu nanoparticles as an additive in liquid paraffin were evaluated with a four-ball friction and wear tester. Findings – It has been found that an as-synthesized Cu nanoparticle has a size of 2-5 nm and can be well dispersed in organic solvents. Tribological properties evaluation results show that as-synthesized Cu nanoparticles possess excellent anti-wear properties as an additive in liquid paraffin. The reason lies in that as-synthesized surface-capped Cu nanoparticles are able to deposit on sliding steel surface and form a low-shearing-strength protective layer thereon, showing promising application as an environmentally acceptable lubricating oil additive, owing to its free phosphorus and sulfur elements characteristics. Originality/value – Oil-soluble surface-modified Cu nanoparticles without phosphorus and sulfur were synthesized and its tribological properties as lubricating oil additives were also investigated in this paper. These results could be very helpful for application of Cu nanoparticles as environment-friendly lubricating oil additives.

Comparisons of tribological properties between laser and drilled dimple textured surfaces of medium carbon steel

2017 ◽  
Vol 69 (4) ◽  
pp. 516-526 ◽  
Author(s):  
Chenchun Shi ◽  
Aibing Yu ◽  
Jianzhao Wu ◽  
Weiyang Niu ◽  
Yanlin Wang
Keyword(s):  
Tribological Properties ◽  
Wear Debris ◽  
Surface Texturing ◽  
Laser Surface Texturing ◽  
Heat Affect Zone ◽  
Textured Surface ◽  
Textured Surfaces ◽  
Wear Properties ◽  
Content Type ◽  
Worn Surfaces

Purpose The study aims to compare tribological properties between laser dimple textured surface and drilled dimple textured surface, and to analyze the influence of dimple hardened edges and ability of trapping wear debris on wear properties of dimple textured surfaces. Design/methodology/approach Circular textured dimples were produced on AISI 1,045 specimen surfaces using laser surface texturing (LST) and drilled surface texturing (DST) methods. Tribological behaviors of LST, DST and non-textured specimens were studied using ball-on-disc tribo-tester. Metallographic structures, dimples and worn surface morphologies were observed using a three-dimensional digital microscope. Hardnesses of substrate and dimple edges were measured. Findings There was no obvious difference in wear and friction coefficients between LST and DST specimens. Hardnesses of laser dimple edges were much higher than that of drilled dimple edges and specimen substrate. The hardened materials of laser dimple edge included recast zone and heat affect zone. Laser dimple was cone-shaped and drilled dimple was cylinder-shaped. Drilled dimple had a better ability of trapping wear debris than laser dimple. Non-uniform wear phenomenon occurred on worn surfaces of LST dimple specimens. Originality/value The ability of textured dimples to trap wear debris is affected by single dimple volume. Hardened edges of dimples cause non-uniform wear on worn surfaces of LST specimens.

Tribological performance, electrochemical behavior and biocompatibility of high-temperature gas-nitrided Ti6Al4V alloy

2018 ◽  
Vol 70 (8) ◽  
pp. 1536-1544 ◽  
Author(s):  
Wen-Hsien Kao ◽  
Yean-Liang Su ◽  
Jeng-Haur Horng ◽  
Shu-Er Yang
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Wear Rate ◽  
Tribological Properties ◽  
Design Methodology ◽  
Tribological Performance ◽  
Ti6al4v Alloy ◽  
Content Type ◽  
Polarization Test ◽  
High Temperature Gas

Purpose This paper aims to investigate the tribology, corrosion resistance and biocompatibility of high-temperature gas-nitrided Ti6Al4V alloy. Design/methodology/approach The tribological properties were studied by reciprocating wear tester. The corrosion resistance was evaluated by using potentiodynamic polarization test. The purified mouse leukaemic monocyte macrophage cells are used to investigate the biocompatibility. Findings The results show that the nitriding treatment leads to a significant improvement in the hardness and tribological properties of Ti6Al4V alloy. Specifically, compared to untreated Ti6Al4V, the hardness increases from 3.24 to 9.02 GPa, while the wear rate reduces by 12.5 times in sliding against a Ti6Al4V cylinder and 19.6 times in sliding against a Si3N4 ball. Furthermore, the nitriding treatment yields an improved corrosion resistance and a biocompatibility similar to that of untreated Ti6Al4V. Originality/value The nitrided Ti6Al4V alloy is an ideal material for the fabrication of load-bearing artificial implants.

Sign in / Sign up

Export Citation Format

Share Document