Enhancement of tribological properties of greases for circuit breakers

MRS Advances ◽  
2018 ◽  
Vol 3 (64) ◽  
pp. 3979-3985
Author(s):  
Brenda Castaños ◽  
Cecilia Fernández ◽  
Laura Peña-Parás ◽  
Demófilo Maldonado-Cortés ◽  
Juan Rodríguez-Salinas
Keyword(s):  
Mass Loss ◽  
Tribological Properties ◽  
Wear Properties ◽  
Circuit Breakers ◽  
Wear Scar Diameter ◽  
Aluminum Complex ◽  
Electrical Industry ◽  
Security Test ◽  
3D Profilometer ◽  
Lithium Complex Grease

ABSTRACTGreases are essential in the electrical industry for the purpose of minimizing wear and coefficient of friction (COF) between the components of circuit breakers. Nowadays some researchers have explored the addition of nanoparticles to enhance their tribological properties. In this study, tribological tests were performed on different greases employed for the electrical industry. CuO and ZnO nanoparticles were homogeneously dispersed into the greases, varying their concentration (0.01 wt.%, 0.05 wt.%, and 0.10 wt.%). A four-ball tribotest, according to ASTM D-2266, and a ball-on-disk tribotest, according to ASTM G-99, were performed in order to analyze the wear scar diameter (WSD), COF, wear mass loss and worn area. The worn materials were characterized with an optical 3D profilometer measurement system. Anti-wear properties were enhanced up to 29.30% for the lithium complex grease (LG) with no nanoparticles added, in comparison with the aluminum complex grease (AG), providing a much better tribological performance; in the ball-on-disk tribotests, a 72.80% and a 15.74% reduction in the mass loss and COF were achieved, respectively. The addition of nanoparticles was found to provide improvements of 5.31% in WSD for the AG grease and 34.49% in COF for the LG grease. A pilot test was performed following the security test UL489, achieving a reduction of 45.17% in the worn area achieved by LG grease compared to AG grease.

The Effect of Lubricant on Tribological Properties of Carbonyl Iron-Based Magnetorheological Fluids

2011 ◽  
Vol 197-198 ◽  
pp. 540-543 ◽  
Author(s):  
Zhi De Hu ◽  
Hua Yan ◽  
Xue Mei Wang ◽  
Hai Zhe Qiu
Keyword(s):  
Tribological Properties ◽  
Carbonyl Iron ◽  
Engineering Application ◽  
Magnetorheological Fluid ◽  
Wear Properties ◽  
Wear Scar Diameter ◽  
Steel Surfaces ◽  
Iron Based ◽  
Friction And Wear Properties ◽  
Worn Surface

Magnetorheological fluid (MRF) is a new kind of smart material, it is very necessary for us to study its tribological properties because it will be widely used in engineering application. In this paper, the tribological behavior of Carbonyl Iron-based magnetorheological fluid (MRF) was investigated on a four-ball tribological tester, the influence of lubricant on friction coefficient and wear scar diameter was discussed, the morphology of the wear steel surfaces lubricated with MRF were observed by a scanning electron microscope. The results show that the addition of MoS2can significantly improve the tribological properties of clay-based MRF. However, the friction and wear properties of silica-based MRF become bad after the addition of MoS2. The morphology of worn surface lubricated with the MRF added MoS2is similar to that without additive, but the groove of wear marks lubricated with clay-based MRF is more shallower and the area of the worn surface is smaller in the condition of adding MoS2.

scholarly journals Preparation and Tribological Properties of Lanthanum Stearate Modified Lubricating Oil for Wire Rope in a Mine Hoist

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5821
Author(s):  
Yewei Zhang ◽  
Qing Zhang ◽  
Yuxing Peng ◽  
Chen Wang ◽  
Xiangdong Chang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Tribological Properties ◽  
High Speed ◽  
Wire Rope ◽  
Dispersion Stability ◽  
Lubricating Oil ◽  
Wear Properties ◽  
Wear Scar Diameter ◽  
Good Thermal Stability ◽  
Mine Hoist

In view of the serious friction and wear on the surface of a hoisting wire rope caused by the failure of lubrication under severe hoisting conditions, a study on the tribological characteristics of lanthanum stearate modified lubricating oil (LSMLO) was carried out. First, lanthanum stearate was prepared by the saponification reaction, and its surface morphology, chemical structure, thermal stability, and dispersion stability in IRIS-550A lubricating oil (IRIS) for wire rope were analyzed. Then, the tribological properties of LSMLO were investigated through four-ball friction tests and sliding wear tests of wire ropes. The results show that stearic acid almost completely reacts to produce lanthanum stearate, which has good thermal stability and a disordered layered structure. With the help of oleic acid, the dispersion stability of lanthanum stearate in IRIS can be significantly improved. The four-ball friction tests show that the optimal addition amount of lanthanum stearate in IRIS is 0.2 wt.%, and the CoF and wear scar diameter are reduced by about 35% and 25% respectively when lubricated with LSMLO compared to that with IRIS. LSMLO can better reduce the wear of the wire rope under different sliding speeds and contact loads than IRIS, and it exhibits improved anti-friction and anti-wear properties under high speed and low load.

Effects of Ag-Carried Content in P/Ag Nanocomposites on Tribological Properties of 45 Mild Steel Friction Pairs

2011 ◽  
Vol 694 ◽  
pp. 17-22 ◽  
Author(s):  
Lǜ Yang ◽  
Yi Li ◽  
Yuan Kang Zhou ◽  
Xue Mei Wu
Keyword(s):  
Friction Coefficient ◽  
Mild Steel ◽  
Mass Loss ◽  
Tribological Properties ◽  
Silver Content ◽  
Testing Machine ◽  
Lubricant Additive ◽  
Wear Properties ◽  
Surface Topographies ◽  
The One

In this paper, some Ag-carried palygorskite nanocomposites P/Ag were prepared, their silver content were 1.3%, 4.61%, 9.54% separately. To investigate the effects of the silver content on tribological properties of 45 mild steel pairs, the P/Ag carried different Ag content were used as lubricant additive and their tribological properties were tested on the MMU-10G testing machine. The wear mass loss is used to assess the anti-wear properties of different additives. The surface topographies and main elements are analyzed through SEM and EDS after running for 30 hours. The results show that the friction coefficient and the wear mass loss significantly decrease along with the increase of silver content in the P/Ag: the average friction coefficient of the P/Ag with 9.54% silver reduces about 65% as much as the one with 1.3% silver, meanwhile, the wear mass loss decreases 57% likewise. The surfaces after rubbing 30 hours, some kind of auto-restoration films that contains sort of characteristic elements such as O, Si, Mg, Al, Ag etc. are formed on the surfaces. With the help of this kind of films, the anti-wear properties of the friction pairs are finally improved. The factors that cause the improvement of anti-friction properties of the friction pairs lie in the quality and the silver content of the auto-restoration films formed on the surfaces of friction pairs.

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.

Amorphous Carbon Coatings for Locally Adjusted Tribological Properties in Sheet Bulk Metal Forming

2012 ◽  
Vol 504-506 ◽  
pp. 969-974 ◽  
Author(s):  
Harald Hetzner ◽  
Stephan Tremmel ◽  
Sandro Wartzack
Keyword(s):  
Amorphous Carbon ◽  
Tribological Properties ◽  
Metal Forming ◽  
Friction And Wear ◽  
Wear Properties ◽  
Carbon Coatings ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Friction And Wear Properties ◽  
Amorphous Carbon Coatings

In sheet bulk metal forming, locally adapted friction properties of the contact tool/workpiece are an appropriate means for the targeted enhancement of the material flow, enabling an improved form filling and lowered forming forces. However, the implementation of desirable friction conditions is not trivial. And further, friction is inseparably linked to wear and damage of the contacting surfaces. This calls for a methodological approach in order to consider tribology as a whole already in the early phases of process layout, so that tribological measures which allow fulfilling the requirements concerning local friction and wear properties of the tool surfaces, can already be selected during the conceptual design of the forming tools. Thin tribological coatings are an effective way of improving the friction and wear properties of functional surfaces. Metal-modified amorphous carbon coatings, which are still rather new to the field of metal forming, allow tackling friction and wear simultaneously. Unlike many other types of amorphous carbon, they have the mechanical toughness to be used in sheet bulk metal forming, and at the same time their friction properties can be varied over wide ranges by proper choice of the deposition parameters. Based on concrete research results, the mechanical, structural and special tribological properties of tungsten-modified hydrogenated amorphous carbon coatings (a-C:H:W) are presented and discussed against the background of the tribological requirements of a typical sheet bulk metal forming process.

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.

Experimental Research on Tribological Properties of Mn0.78Zn0.22Fe2O4 Magnetic Fluids

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Wang Li-jun ◽  
Guo Chu-wen ◽  
Ryuichiro Yamane
Keyword(s):  
Tribological Properties ◽  
Friction And Wear ◽  
Chemical Properties ◽  
Friction Reduction ◽  
Experimental Investigations ◽  
Wear Scar Diameter ◽  
Base Oil ◽  
Turbine Oil ◽  
Physical And Chemical ◽  
And Chemical Properties

The synthesis and application of nanometer-sized particles have received considerable attention in recent years because of their different physical and chemical properties from those of the bulk materials or individual molecules; however, few experimental investigations on the tribological properties of lubricating oils with and without nanoferromagnetic particles have been performed. This work investigates the tribological properties of Mn0.78Zn0.22Fe2O4 nanoferromagnetic as additive in 46# turbine oil using a four-ball friction and wear tester. It is shown that the 46# turbine oil containing Mn0.78Zn0.22Fe2O4 nanoparticles has much better friction reduction and antiwear abilities than the base oil. The 46# turbine oil doped with 6wt%Mn0.78Zn0.22Fe2O4 nanoparticles show the best tribological properties among the tested oil samples, and PB value is increased by 26%, and the decreasing percentage of wear scar diameter is 25.45% compared to base oil.

scholarly journals The tribological properties study of carbon fabric/ epoxy composites reinforced by nano-TiO2 and MWNTs

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 1127-1138 ◽  
Author(s):  
Fengjun Wei ◽  
Bingli Pan ◽  
Juan Lopez
Keyword(s):  
Tribological Properties ◽  
Friction And Wear ◽  
Epoxy Composite ◽  
Good Effect ◽  
Binder Phase ◽  
Carbon Fabric ◽  
Wear Properties ◽  
Brittle Rupture ◽  
Composites Materials ◽  
The Coefficient Of Friction

Abstract A kind of carbon fabric/epoxy composite was successfully prepared with carbon fiber fabric as reinforced phase and epoxy resin as binder phase, then the nano-TiO2 and a hybrid system of TiO2/MWNTs was added into the carbon fabric/ epoxy composite matrix respectively to prepare a kind of nano-composite. The friction and wear properties of CF/EP composites under different load conditions have been studied in this article, during the study the effects of filler types and contents on the tribological properties were researched, at last the worn surfaces were investigated and the abrasion mechanism was discussed. The results showed that: whether filling the nano-TiO2 alone or mixing the TiO2/MWNTs, it was able to achieve a good effect on decreasing friction and reducing wear, and the optimum addition ratio of the nano-TiO2 particles was 3.0% , meanwhile 3.0% of nano-TiO2 and 0.4% of MWNTs could cooperate with each other in their dimension, and could show a synergistic effect on modifying the tribological properties of CF/EP composites, the coefficient of friction of the modified composites decreased by 20% and the wear life increased by more than 140% compared with that of pristine composite materials, in the process of friction and wear, the wear form of the composites materials varied from brittle rupture to abrasive wear gradually.

scholarly journals Fabrication and Tribological Properties of Copper Matrix Solid Self-Lubricant Composites Reinforced with Ni/NbSe2 Composites

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1854
Author(s):  
Fei-xia Zhang ◽  
Yan-qiu Chu ◽  
Chang-sheng Li
Keyword(s):  
Powder Metallurgy ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Copper Matrix ◽  
Wear Properties ◽  
Disk Friction ◽  
Friction Reducing ◽  
Properties Of Composites

This paper presents a facile and effective method for preparing Ni/NbSe2 composites in order to improve the wettability of NbSe2 and copper matrix, which is helpful in enhancing the friction-reducing and anti-wear properties of copper-based composites. The powder metallurgy (P/M) technique was used to fabricate copper-based composites with different weight fractions of Ni/NbSe2, and tribological properties of composites were evaluated by using a ball-on-disk friction-and-wear tester. Results indicated that tribological properties of copper-based composites were improved by the addition of Ni/NbSe2. In particular, copper-based composites containing 15 wt.% Ni/NbSe2 showed the lowest friction coefficient (0.16) and wear rate (4.1 × 10−5 mm3·N−1·m−1) among all composites.

scholarly journals Effects of Reduced Graphene Oxide (rGO) at Different Concentrations on Tribological Properties of Liquid Base Lubricants

Lubricants ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 11 ◽  
Author(s):  
Jankhan Patel ◽  
Amirkianoosh Kiani
Keyword(s):  
Graphene Oxide ◽  
Physical Properties ◽  
Reduced Graphene Oxide ◽  
Tribological Properties ◽  
High Speed ◽  
Friction And Wear ◽  
Control Sample ◽  
Wear Properties ◽  
Reduced Graphene ◽  
Friction And Wear Properties

In this study, reduced graphene oxide (rGO) nano platelets were used as an additive to enhance friction and wear properties of oil-based lubricants by preparing three samples at 0.01% w/w, 0.05% w/w, and 0.1% w/w concentrations. To analyze the direct effect of rGO nano platelets on tribological properties, 99.9% pure oil was used as a liquid lubricant. A comparative tribological study was done by performing a ball-on-disk wear test in situ under harsh conditions, which was further analyzed using a non-contact 3D optical profilometer. Morphological evaluation of the scar was done using transmission and scanning electron microscopy (TEM, SEM) at micro and nano levels. The lubricants’ physical properties, such as viscosity and oxidation number, were evaluated and compared for all samples including pure oil (control sample) as per ASTM standards. Findings of all these tests show that adding rGO nano platelets at 0.05% w/w showed significant reduction in friction at high speed and in wear up to 51.85%, which is very promising for increasing the life span of moving surfaces in machinery. Oxidation and viscosity tests also proved that adding rGO nano platelets to all samples does not sacrifice the physical properties of the lubricant, while it improves friction and wear properties.

Sign in / Sign up

Export Citation Format

Share Document