Effect of thermal activation on the tribological behaviors of muscovite particles as lubricant additives in lithium grease

2018 ◽  
Vol 70 (3) ◽  
pp. 538-543 ◽  
Author(s):  
Pengfei Du ◽  
G.X. Chen ◽  
Shiyuan Song ◽  
Jiang Wu ◽  
Kechen Gu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Tribological Properties ◽  
Thermal Activation ◽  
Layer Structure ◽  
Lubricant Film ◽  
Lubricant Additives ◽  
Activation Temperature ◽  
Lithium Grease ◽  
Content Type ◽  
Worn Surface

Purpose The tribological properties of muscovite and its thermal-treated products as lubricant additives in lithium grease were investigated. The effect of thermal temperature on the crystal structure and tribological properties of muscovite was studied. This study aims to explore the tribological mechanism of muscovite and optimize a proper thermal activation temperature, thus further improving the tribological properties. Design/methodology/approach The crystal structure of muscovite samples was characterized by SEM, TG-DSC, XRD and FTIR. The tribological properties of grease samples were investigated using a four-ball tribotester and the worn surface was analyzed by SEM and EDS. Findings The excellent tribological properties of muscovite can be ascribed to the layer structure and lubricant film formed on the worn surface. Thermal temperature at 500-600°C increases the surface activity and oxygen releasing capability, and thus favors the formation of lubricant film and accordingly further improves the tribological properties. However, the layer structure is destroyed and hard phases such as alumina and amorphous appear after thermal temperature activated beyond 1000°C, as it results in the aggravation of friction and wear. Originality/value To the authors’ knowledge, it is the first to study the effect of thermal temperature on the crystal structure and tribological properties of muscovite. The tribological mechanism of muscovite particle and its thermal-treated products was disclosed.

Tribological behaviors of some novel dimercaptothiadiazole derivatives containing hydroxyl as multifunctional lubricant additives in biodegradable lithium grease

2014 ◽  
Vol 66 (1) ◽  
pp. 51-61 ◽  
Author(s):  
Huan Chen ◽  
Junhui Jiang ◽  
Tianhui Ren ◽  
Lei Zheng ◽  
Yidong Zhao
Keyword(s):  
Lubricant Additives ◽  
Short Chain ◽  
Lithium Grease ◽  
Edge Structure ◽  
Content Type ◽  
Organic Sulfide ◽  
Ferrous Sulfide ◽  
Heterocyclic Derivatives ◽  
Main Component ◽  
Thermal Films

Purpose – In order to meet the requests of exploring environmental-friendly and multifunctional lubricant additives, some novel dimercaptothiadiazole derivatives containing hydroxyl are prepared and used as antiwear (AW) and extreme-pressure (EP) additives in biodegradable lithium grease. The paper aims to discuss these issues. Design/methodology/approach – The tribological performances of the grease samples containing these derivatives are evaluated by using a four-ball tester. X-ray absorption near edge structure (XANES) spectroscopy is used to analyze the chemistry of tribofilms under AW/EP regime, and thermal films are also considered for comparison. Findings – The tribological tests show that these derivatives are all effective in reducing wear, especially at lower additive concentrations, but they are basically failed in reducing friction. They are also helpful in improving the EP characteristic of the base grease. The thermal films generated by these derivatives are composed of adsorbed organic sulfide and ferrous sulfate, though for short-chain derivatives, organic sulfide is the only component at 5.0 wt.%. Ferrous sulfide is the main component of the tribofilms formed by these derivatives at various additive concentrations. But for short-chain derivatives, these tribofilms consist of ferrous sulfide and ferrous disulfide at 5.0 wt.%, and the appearance of disulfide suggests that the interfacial temperature between the upper ball and three lower balls under these conditions is considerably low. The EP films generated by short-chain derivatives are all composed of organic sulfide and ferrous sulfide, while for long-chain derivatives, ferrous sulfide is the main component. Originality/value – These low-toxic and oil-soluble dimercaptothiadiazole derivatives are effective in improving the tribological characteristic of the biodegradable lithium grease, and these heterocyclic derivatives may be good substitutes for some harmful traditional additives.

scholarly journals Tribological Properties of ZnS(NH2CH2CH2NH2)0.5 and ZnS as Additives in Lithium Grease

Lubricants ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 26 ◽  
Author(s):  
Aoxiang Lu ◽  
Wenxing Niu ◽  
Yingjing Dai ◽  
Hong Xu ◽  
Jinxiang Dong
Keyword(s):  
Tribological Properties ◽  
Industrial Applications ◽  
Dimensional Structure ◽  
Layered Compound ◽  
Synthetic Method ◽  
Wear Properties ◽  
Wear Performance ◽  
Lithium Grease ◽  
Test Conditions ◽  
Worn Surface

The layered compound ZnS(NH2CH2CH2NH2)0.5 was evaluated as an additive in grease with different concentrations by using a four-ball tribometer. Results show that ZnS(NH2CH2CH2NH2)0.5 grease has good load bearing ability and excellent anti-wear properties. ZnS(NH2CH2CH2NH2)0.5 revealed better wear resistance than that of ZnS under all test conditions. The reason for this may be that the two-dimensional structure of ZnS(NH2CH2CH2NH2)0.5, with larger interspaces, facilitates an easier sliding process, improving the anti-wear performance. The mechanism was estimated through analysis of the worn surface with SEM, EDS, 3D, and XPS. XPS analysis results show that the tribofilm was mainly composed of FeS, ZnS, ZnO, FexOy, Feu(SO4)v, and ZnSO4. Owing to the simple synthetic method and superior tribological properties as a grease-based additive, ZnS(NH2CH2CH2NH2)0.5 holds great potential for use in demanding industrial applications in the future.

Effect of load on the tribological properties of Si3N4-hBN composite ceramics sliding against Si3N4

2018 ◽  
Vol 70 (9) ◽  
pp. 1699-1705
Author(s):  
Dong Qiang Gao ◽  
Rui Wang ◽  
Wei Chen
Keyword(s):  
Abrasive Wear ◽  
Tribological Properties ◽  
Wear Mechanism ◽  
Friction And Wear ◽  
Water Lubrication ◽  
Content Type ◽  
Lubrication Film ◽  
Pin On Disc ◽  
Lubrication Condition ◽  
Worn Surface

Purpose The effect of the load on the tribological properties of Si3N4-hBN sliding against Si3N4 were investigated under dry and water lubrication condition. Design/methodology/approach Using a MMU-5G type pin-on-disc friction and wear tester. Findings Under the dry friction, the wear mechanism was dominated by ploughing and abrasive wear, and the contact status was elastic contact under the load less than 25 N. With the increase of the load, the friction coefficient decreased; the main wear mechanism was fatigue fracture, and the contact status turned into plastic contact. Under water lubrication, effective lubrication film could be produced on the worn surface, and it had a function of fluid lubrication under the load less than 15 N. With the increase of the load, the pin and the disc came into direct contact, and the friction and wear of the pairs were aggravated; the wear mechanism changed from chemical wear into abrasive wear and brittle spalling. Originality/value The study on the effect of the load on the tribological properties of Si3N4-hBN sliding against Si3N4 was investigated under dry and water lubrication condition in the way of contact stress.

Study of the effect of overbased calcium or magnesium sulfonate combinated with thiazole derivatives in rapeseed oil on tribological properties

2018 ◽  
Vol 70 (7) ◽  
pp. 1258-1267
Author(s):  
Juan Tan ◽  
Yanfei Wang ◽  
Mouwu Liu ◽  
Jing Liu
Keyword(s):  
Iron Oxides ◽  
Tribological Properties ◽  
Rapeseed Oil ◽  
Single Agent ◽  
Lubricant Film ◽  
Thiazole Derivatives ◽  
Alkyl Benzene ◽  
Alkyl Benzene Sulfonate ◽  
Content Type ◽  
Worn Surfaces

Purpose The purpose of this paper is to study the tribological properties of a thiazole derivatives (T561), overbased alkyl benzene calcium sulfonate (T106A) compounded with T561 and overbased alkyl benzene magnesium sulfonate (T107) compounded with T561 in rapeseed oil (RSO). Design/methodology/approach A four-ball machine was used to evaluate the tribological properties of each compound and their combinations with T561 in RSO. Scanning electron microscopy, EDX and X-ray photoelectron spectroscopy were applied to analyze the tribofilm formed on the worn surfaces. Findings Results of tribotesting demonstrated that synergistic effects exist between the overbased sulfonates, T106A and T107, and the thiazole derivative, T561. The texts of tribofilm indicated that iron sulfide and iron oxides exist in T561 single agent lubricant film and two composite additives lubricant film, and no sulfates were detected. It suggested that the addition of alkyl benzene sulfonate did not hinder the formation of iron sulfides and iron oxides. Meanwhile, CaSO4 (MgSO4) and CaCO3 (MgCO3) were detected on the worn surface of the composite additives, which were not detected on the single agent friction surface. Originality/value A tribofilm mainly contains CaSO4 (MgSO4) and CaCO3 (MgCO3) formed on the worn surfaces, which is responsible for excellent extreme pressure and anti-wear properties of the compound agents because of their high melting point and high shear stress.

scholarly journals Preparation and Tribological Properties of Dual-Coated TiO2Nanoparticles as Water-Based Lubricant Additives

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Yue Gu ◽  
Xiuchen Zhao ◽  
Ying Liu ◽  
Yunxia Lv
Keyword(s):  
Tribological Properties ◽  
Titanium Dioxide Nanoparticles ◽  
Pure Water ◽  
Lubricant Additives ◽  
Wear Scar ◽  
Drilling Process ◽  
Wear Scar Diameter ◽  
Water Based ◽  
The Coefficient Of Friction ◽  
Worn Surface

Titanium dioxide nanoparticles (TiO2) were synthesized and then dual-coated with silane coupling agent (KH-570) and OP-10 in sequence in order to be dispersed stably in water as lubricant additives. The tribological properties and the application performance in Q235 steel machining of the nanoparticles as water-based lubricant additives were investigated on an MSR-10D four-ball tribotester and on a bench drilling machine, respectively. Scanning electron microscope (SEM) and atomic force microscope (AFM) were used to analyze the worn surface. The results show that the surface-modified TiO2nanoparticles can remarkably improve the load-carrying capacity, the friction reducing, and anti wear abilities of pure water. The wear scar diameter and the coefficient of friction of the water-based lubricating fluids with TiO2nanoparticles decreased, and the thick deep furrows on the surface of wear scar also decreased obviously with the increase of TiO2concentration. The power consumption in drilling process was lower and the cutting surface was smoother using the water-based lubricating fluids added TiO2nanoparticles compared to the fluid without addition. The reason for nanoparticles improving tribological properties of water based lubricating fluid might be the formation of a dynamic deposition film during rubbing process according to analysis of the worn surface.

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.

Tribological properties of zirconium phosphate-quinoline compound as an additive in lithium grease

2018 ◽  
Vol 70 (8) ◽  
pp. 1487-1493
Author(s):  
Wenxing Niu ◽  
Lei Liu ◽  
Hong Xu ◽  
Jinxiang Dong
Keyword(s):  
Tribological Properties ◽  
Direct Contact ◽  
Three Dimensional ◽  
Lubricant Additive ◽  
High Load ◽  
Lithium Grease ◽  
Content Type ◽  
Post Test ◽  
Long Time ◽  
Time Test

Purpose The purpose of this paper is to study the tribological properties of (C9H8N)4(H2O)4[Zr8P12O40(OH)8F8] (designated as ZrPOF-Q1) used as an additive in lithium grease. Design/methodology/approach The tribological properties of ZrPOF-Q1 as an additive in the lithium grease were evaluated with a four-ball tester. To understand the lubrication mechanism, post-test characterization of the contact tracks was performed via three-dimensional (3D) optical profiler, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Findings The results reveal that ZrPOF-Q1 exhibits good performance in anti-wear, friction-reducing and load-carrying capacity. The action mechanism is estimated through analysis of the worn surface with SEM, EDS and 3D. The results indicate that ZrPOF-Q1 can adhere on the substrate, protecting the rubbed surfaces from a direct contact, even under high load for a long-time test. ZrPOF-Q1 can adhere on the substrate, protecting the rubbed surfaces from a direct contact, even under high load for a long-time test. Originality/value This work illustrates that ZrPOF-Q1 as an additive can improve lubricating performance. These tribological properties make ZrPOF-Q1 a promising candidate for lubricant additive.

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.

Study on the tribological behaviors of copper nanoparticles in three kinds of commercially available lubricants

2018 ◽  
Vol 70 (3) ◽  
pp. 519-526 ◽  
Author(s):  
Yanhong Li ◽  
TianTian Liu ◽  
Yujuan Zhang ◽  
Pingyu Zhang ◽  
Shengmao Zhang
Keyword(s):  
Tribological Properties ◽  
Design Methodology ◽  
Electrical Contact ◽  
Three Dimensional ◽  
Lubricant Additives ◽  
Load Carrying Capacity ◽  
Electrical Contact Resistance ◽  
Content Type ◽  
Load Carrying ◽  
Wear Tests

Purpose The purpose of this paper is to study the tribological properties of Cu nanoparticles (NPs) as lubricant additives in three kinds of commercially available lubricants. Design/methodology/approach A four-ball machine is used to estimate the tribological properties of Cu NPs as lubricant additives in three kinds of commercially available lubricants. Three-dimensional optical profiler and electrical contact resistance are evaluated to investigate the morphology of the worn surfaces and the influence of Cu NPs on tribofilms. Findings Wear tests show that the addition of Cu NPs as lubricant additives could reduce wear and increase load-carrying capacity of commercially available lubricants remarkably, indicating that Cu NPs have a good compatibility with the existing lubricant additives in commercially available lubricants. Originality/value The tribological properties of Cu NPs as lubricant additives in three kinds of commercially available lubricants were investigated in this paper. These results are reliable and can be very helpful for application of Cu NPs as lubricant additives in industry.

Tribological study of TiO2 nanoparticles modified with stearic acid as additives in lithium grease

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hong Zhang ◽  
Sheng Han ◽  
Wenjing Hu ◽  
Jiusheng Li
Keyword(s):  
Surface Modification ◽  
Electron Microscope ◽  
Stearic Acid ◽  
Metal Nanoparticles ◽  
Tio2 Nanoparticles ◽  
Tribological Properties ◽  
Lithium Grease ◽  
Content Type ◽  
Prepared Nanoparticles ◽  
Steel Balls

Purpose The purpose of this paper is to improve the properties of metal nanoparticles which are easy to agglomerate and hard to disperse evenly, thus limiting the application of metal nanoparticles in grease. A novel technology was proposed for modifying metal oxide to improve the dispersibility of nanoparticles. Design/methodology/approach SA-TiO2 nanoparticles were synthesized using an in-situ esterification method followed by surface modification with stearic acid. The microstructure of the nanoparticles was characterized by scanning electron microscope, transmission electron microscope and Fourier transform infrared spectroscopy and their thermal stability was evaluated by thermogravimetric analyzer. The tribological properties of the SA-TiO2 nanoparticles as additives in lithium grease were evaluated with a four-ball tester and TE77 reciprocating friction tester. The worn surfaces of the steel balls were investigated by EDS and XPS. Findings The prepared nanoparticles can be well dispersed in the lithium grease and possess much better tribological properties compared to traditional nanoparticles. The results indicated that the excellent tribological performance of SA-TiO2 was attributed to the chemical reaction film composing of Fe2O3, iron oxide and other organic compounds. Originality/value This paper provides a method to prevent the agglomeration of nano-TiO2 by surface modification with stearic acid. And the prepared nanoparticles can effectively improve the tribology performance of lithium grease.

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