Effects of woven liners treated by LaCl3 or CeO2 solution on film formation mechanisms of self-lubricating radial spherical plain bearings

2016 ◽  
Vol 68 (3) ◽  
pp. 308-314 ◽  
Author(s):  
Ming Qiu ◽  
Yanwei Miao ◽  
Yingchun Li ◽  
Long Chen ◽  
Rensong Hu ◽  
...  
Keyword(s):  
Abrasive Wear ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Film Formation ◽  
Energy Dispersive Spectrometer ◽  
Sem Analysis ◽  
Formation Mechanisms ◽  
Wear Properties ◽  
Content Type ◽  
Cooling Effects

Purpose The fabric self-lubricating liners are the key factors impacting the performances of self-lubricating spherical plain bearings. The purpose of this paper is to improve the friction and wear properties of self-lubricating radial spherical plain bearings by modification of the liners. Design/methodology/approach The liners of hybrid woven PTFE/Kevlar fabrics were treated respectively by the LaCl3 and CeO2 solutions. The tribological properties of self-lubricating spherical plain bearings with treated or untreated liners under continuous swaying conditions were investigated with the bearing tester at the swaying frequency of 2.5 Hz and the swaying angle of ±10°. The film formation and wear mechanisms were analyzed based on the observation of worn surfaces with a scanning electron microscope (SEM) and an energy dispersive spectrometer (EDS). Findings Results show that the tribological properties of the bearings treated by the LaCl3 or CeO2 solution were improved compared with those of the untreated bearings. In particular, the wear resistance of bearings treated by the CeO2 solution was remarkably improved under higher swaying cycles, but the anti-friction properties and cooling effects of bearings treated by the LaCl3 solution were better under lower swaying cycles. Through SEM analysis, the reasons were analyzed. The bearings with treated liners only produced slight adhesive and abrasive wear, but the bearings with untreated liners produced more serious adhesive and abrasive wear under higher swaying cycles. Originality/value The paper proposed a new pretreatment process for the self-lubricating liners. The investigation on the friction and wear behaviors of the bearings is beneficial for prolonging the service lives of the radial spherical plain bearings.

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.

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.

NBR surface modification by Ar plasma and its tribological properties

2016 ◽  
Vol 68 (2) ◽  
pp. 227-232 ◽  
Author(s):  
Dawit Zenebe Segu
Keyword(s):  
Plasma Treatment ◽  
Bias Voltage ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Butadiene Rubber ◽  
Rf Power ◽  
Wear Properties ◽  
Content Type ◽  
Ion Plasma ◽  
Ar Plasma

Purpose – The purpose of this paper is to study the possibility and validity of using radio frequency (RF) power argon (AR) ion plasma treatment to modify the surface of nitrile butadiene rubber (NBR) and the change in the chemical structure under various bias voltage. Using wear test, the authors also compared the friction and wear properties of untreated and treated NBR. Design/methodology/approach – The hybrid RF-power sputtering system was used to generate RF Ar plasma to modify the surface of NBR specimens. The tribological properties were evaluated by ball-on-disc test using a load cell mounted on the ball holder. Findings – It was found that the NBR surface treated by the Ar plasma improved the wettability, friction and wear performance than the untreated NBR. The ATR-IR analysis indicated that the improvement come from the oxygen based functional groups generated on the surface of NBR. The improvement of friction and wear resistance may also come from the formation of nanostructure surface. Originality/value – In this study, the authors develop the RF AR ion plasma treatment at different bias voltage, and it has been used to modify the surface of NBR to increase the tribological performance.

Effects of iron content on tribological properties of Cu-Fe-based friction material

2019 ◽  
Vol 71 (5) ◽  
pp. 718-723
Author(s):  
Yanxin Zheng ◽  
Ying Liu ◽  
Feng Zheng ◽  
Qingsong Song ◽  
Caili Zhang ◽  
...  
Keyword(s):  
Tribological Properties ◽  
Iron Content ◽  
Friction And Wear ◽  
Sliding Friction ◽  
Friction Material ◽  
High Load ◽  
Wear Properties ◽  
Sliding Speed ◽  
Friction Materials ◽  
Content Type

Purpose The purpose of this study is to investigate the effect of iron content on the friction and wear performances of Cu–Fe-based friction materials under dry sliding friction and wear test condition. Design/methodology/approach Cu–Fe-based friction materials with different iron content were prepared by powder metallurgy route. The tribological properties of Cu–Fe-based friction materials against GCr15 steel balls were studied at different applied loads and sliding speeds. Meanwhile, microstructure and phases of Cu–Fe-based friction materials were investigated. Findings Cu–Fe-based friction materials with different iron content are suitable for specific applied load and sliding speed, respectively. Low iron content Cu–Fe-based friction material is suitable for a high load 60 N and low sliding speed 70 mm/min and high iron content Cu–Fe-based friction material will be more suitable for a high load 60 N and high sliding speed 150 mm/min. The abrasive wear is the main wear mechanism for two kinds of Cu–Fe-based friction materials. Originality/value The friction and wear properties of Cu–Fe-based friction materials with different iron content were determined at different applied loads and sliding speeds, providing a direction and theoretical basis for the future development of Cu–Fe-based friction materials.

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.

A comparative study of the friction and wear performance of Fe-based bulk metallic glass under different conditions

2017 ◽  
Vol 69 (6) ◽  
pp. 919-924
Author(s):  
Dawit Zenebe Segu ◽  
Pyung Hwang
Keyword(s):  
Metallic Glass ◽  
Abrasive Wear ◽  
Bulk Metallic Glass ◽  
Friction And Wear ◽  
Deionized Water ◽  
Wear Scar ◽  
Dry Sliding ◽  
Wear Performance ◽  
Content Type ◽  
Conventional Material

Purpose This study aims to compare the friction and wear behaviors of Fe68.3C6.9Si2.5 B6.7P8.8Cr2.2Al2.1Mo2.5 bulk metallic glass (BMG) under sliding using dry, deionized water-lubricated and oil-lubricated conditions. The comparison was performed using a unidirectional ball-on-flat tribometer under different applied loads, and the results were compared to the properties of a conventional material, SUJ2. Fe-based BMG materials have recently been attracting a great deal of attention for prospective engineering applications. Design/methodology/approach As a part of the development of Fe-based BMGs that can be cost-effectively produced in large quantities, an Fe-based BMG Fe68.8C7.0Si3.5B5.0P9.6 Cr2.1Mo2.0Al2.0 with high glass forming ability was fabricated. In the present study, the friction and wear properties of Fe-based BMG has been comparatively evaluated under dry sliding, deionized water- and oil-lubricated conditions using a unidirectional ball-on-flat tribometer under different applied loads, and the results were compared to the properties of conventional material SUJ2. Findings The results show that the Fe-based BMG had better friction performance than the conventional material. Both the friction coefficient and wear mass loss increased with increasing load. The sliding wear mechanism of the BMG changed with the sliding conditions. Under dry sliding conditions, the wear scar of the Fe-based BMG was characterized by abrasive wear, plastic deformation, micro-cracks and peeling-off wear. Under water- and oil-lubricated conditions, the wear scar was mainly characterized by abrasive wear and micro-cutting. Originality/value In this investigation, the authors developed a new BMG alloy Fe68.8C7.0Si3.5B5.0P9.6Cr2.1Mo2.0Al2.0 to improve the friction and wear performance under dry sliding, deionized water- and oil- lubricated conditions.

Tribological properties of beef tallow as lubricating grease

2017 ◽  
Vol 69 (5) ◽  
pp. 645-654 ◽  
Author(s):  
Juozas Padgurskas ◽  
Raimundas Rukuiža ◽  
Ihor Mandziuk ◽  
Arturas Kupcinskas ◽  
Katerina Prisyazhna ◽  
...  
Keyword(s):  
Critical Load ◽  
Tribological Properties ◽  
Beef Tallow ◽  
Friction And Wear ◽  
Load Level ◽  
Synthesis Process ◽  
Polymer Additives ◽  
Lubricating Grease ◽  
Content Type ◽  
Thermally Processed

Purpose The purpose of this paper is to report on the tribological properties of beef tallow grease and improvements therein through modification with special processing, polymeric compounds and additives. Design/methodology/approach Pure original beef tallow grease was used as a biological lubricating grease reference material for the tribological research. Beef tallow was modified and synthesized by adding special biological anti-oxidant additives, LZ anti-wear additives, waste polyethylene terephthalate (PET) polymer compounds and thermally processed graphite. Findings Rheometric measurements indicate that the beef tallow grease modification technology used in this study enables control of the synthesis process to produce lubricants with the required microstructure. Investigation results of the tribological properties of differently modified greases show that beef tallow synthesized with polymer additives efficiently operates together with anti-wear additives to reduce friction and wear. The grease compound with thermally processed graphite has good tribological properties at 300 N load levels. The critical load level of lubricating greases could be significantly increased through the use of anti-wear additives and thermally processed graphite. Originality/value Investigation results of the tribological properties of differently modified beef tallow greases show that beef tallow synthesized with polymer additives efficiently operates together with anti-wear additives to reduce friction and wear. The critical load level of lubricating beef tallow greases could be significantly increased using anti-wear additives and thermally processed graphite.

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