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 ◽  
...  

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.

2018 ◽  
Vol 70 (9) ◽  
pp. 1706-1713 ◽  
Author(s):  
Guotao Zhang ◽  
Yanguo Yin ◽  
Ting Xie ◽  
Dan Li ◽  
Ming Xu ◽  
...  

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.


2019 ◽  
Vol 72 (1) ◽  
pp. 172-179 ◽  
Author(s):  
Meiling Wang

Purpose The purpose of this study is to investigate the effect of engineered micro-structures on the tribological properties of metal-polyetheretherketone (PEEK) surface. Design/methodology/approach Circular dimples with diameters of 25 and 50 µm were designed and manufactured on PEEK plate specimens using picosecond laser. Reciprocating friction and wear tests on a ball-on-flat configuration were performed to evaluate the tribological properties of the designed micro-structures in dry contacts. The loading forces of 0.9 and 3 N were applied. Findings As a result, obvious fluctuations of coefficient of friction curve were observed in tribosystems consisting of non-textured and textured PEEK with circular dimples of 25 µm in diameter. GCr15 ball/textured PEEK plate specimens with circular dimples of 50 µm in diameter revealed a superior friction and wear property. Originality/value Different to the existing studies in which the tribopairs consist of hard bearing couples, this study investigated the tribological properties of the engineered micro-structures on the hard-on-soft bearing couples.


2014 ◽  
Vol 66 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Zhengfeng Jia ◽  
Yan-qiu Xia ◽  
Xin Shao ◽  
San-ming Du

Purpose – The purpose of this paper is to investigate the tribological properties of poly-alpha-olefin (PAO) with nano/microstructure core-shell lanthanum borate-SiO2 composites (OCLS). Design/methodology/approach – Oleic acid-capped core-shell lanthanum borate-SiO2 composites were synthesized by an easy way. The composites were characterized by means of Fourier transform-infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and thermo gravimetric analysis (TGA). The friction and wear behaviors of the quenched AISI 1045 steel specimens sliding against AISI 52100 steel under the lubrication of PAO containing OCLS were comparatively investigated with PAO containing SiO2 additive on an Optimol SRV reciprocating friction and wear tester. On the other hand, the tribological properties of the PAO containing OCLS were also investigated on four-ball tester. Findings – The diameter of OCLS was about 20 nm, and the thickness of the SiO2 shell was less than 5 nm. The ratio of oleic acid (OA) is about 15 percent. The PAO containing OCLS possesses much better tribological properties than that of pure PAO and PAO containing SiO2 additive. Originality/value – The PAO+OCLS possess a better friction reducing and antiwear properties than pure PAO. The new additive can improve the tribological ability of machinery.


2014 ◽  
Vol 66 (4) ◽  
pp. 538-544 ◽  
Author(s):  
Tiedan Chen ◽  
Yanqiu Xia ◽  
Zhilu Liu ◽  
Zeyun Wang

Purpose – The mixture of attapulgite and bentonite was used as a thickener, and polyalphaolefin was used as the base oil to prepare the new lubricating grease. Some solid particles such as Polytetrafluoroethene (PTFE), MoS2, nano-calcium carbonate and graphite were added in the new lubricating grease as anti-wear additives to investigate the tribological sensitivity. Design/methodology/approach – The new lubricating grease was evaluated by optimol-SRV reciprocating friction and wear tester, and the wear volumes were determined using a MicroXAM-3D. At the same time, the dropping point and the cone penetration were investigated and analyzed. The tribological properties of the new lubricating grease and the sensitivity of some solid lubricating additives to the new lubricating base grease were investigated; pure organic-bentonite and pure organic-attapulgite base grease were used as contrast. Findings – The new lubricating grease based on the surface-modified bentonite/attapulgite clay base grease was synthesized with a relatively high dropping point, and the mass ratio is 25/75 bentonite/attapulgite clay base grease, having a better tribological performance. MoS2 was used as an anti-wear additive that has good tribological sensitivity to the new lubricating base grease. Originality/value – The main innovative thought of this work lies in the mixture of attapulgite and bentonite used as thickener. A relevant report is not available at present.


2018 ◽  
Vol 70 (3) ◽  
pp. 499-505
Author(s):  
Shanhua Qian ◽  
Hongyue Wang ◽  
Chuanhui Huang ◽  
Yongwu Zhao

Purpose This paper aims to modify carbon nanotubes with oleic acid, and to study the tribological properties of castor oil with modified carbon nanotubes additives. The proper additives are sought for the future engineering application of castor oil. Design/methodology/approach Tribological properties of the castor oils mixed with the modified carbon nanotubes of four mass percentages were investigated using a four-ball testing rig. Coefficient of friction and wear scar diameter were obtained in each test, and the mechanism of modified carbon nanotubes and castor oil was discussed. Findings The results indicated that modified carbon nanotubes had better dispersion in castor oil. Coefficient of friction first increased, then decreased and finally grew stable with the time, and wear scar diameter of steel surface functioned as a first reduced then increased change with the additive mass percentage of modified carbon nanotubes. The minimum of average coefficient of friction and wear scar diameter occurred at 0.02 Wt.% modified carbon nanotubes. Originality/value A small amount of modified carbon nanotubes could improve properties of the castor oil, and the mixed castor oil with 0.02 Wt.% modified carbon nanotubes would be most possibly used in engineering applications.


2016 ◽  
Vol 68 (5) ◽  
pp. 577-585 ◽  
Author(s):  
Zhengfeng Cao ◽  
Yanqiu Xia ◽  
Xiangyu Ge

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.


2019 ◽  
Vol 71 (7) ◽  
pp. 931-941 ◽  
Author(s):  
Yazhou Mao ◽  
Yang Jianxi ◽  
Xu Wenjing ◽  
Liu Yonggang

Purpose The purpose of this paper is to investigate the effect of round pits arrangement patterns on tribological properties of journal bearing. In this paper, the tribological behaviors of journal bearing with different arrangement patterns under lubrication condition were studied based on M-2000 friction and wear tester. Design/methodology/approach The friction and wear of journal bearing contact surface were simulated by ANSYS. The wear mechanism of bearing contact surfaces was investigated by the means of energy dispersive spectrum analysis on the surface morphology and friction and wear status of the journal bearing specimens by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometer (EDS). Besides, the wearing capacity of the textured bearing was predicted by using the GM (1,1) and Grey–Markov model. Findings As the loads increase, the friction coefficient of journal bearing specimens decrease first and then increase slowly. The higher rotation speed, the lower friction coefficient and the faster temperature build-up. The main friction method of the bearing sample is three-body friction. The existence of texture can effectively reduce friction and wear. In many arrangement patterns, the best is 4# bearing with round pits cross-arrangement pattern. Its texturing diameters are 60 µm and 125 µm, and the spacing and depth are 200 µm and 25 µm, respectively. In addition, the Grey–Markov model prediction result is more accurate and fit the experimental value better. Originality/value The friction and wear mechanism is helpful for scientific research and engineers to understand the tribological behaviors and engineering applications of textured bearing. The wear capacity of textured bearing is predicted by using the Grey–Markov model, which provides technical help and theoretical guidance for the service life and reliability of textured bearing.


2018 ◽  
Vol 70 (9) ◽  
pp. 1699-1705
Author(s):  
Dong Qiang Gao ◽  
Rui Wang ◽  
Wei Chen

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.


2016 ◽  
Vol 68 (2) ◽  
pp. 227-232 ◽  
Author(s):  
Dawit Zenebe Segu

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.


2019 ◽  
Vol 71 (5) ◽  
pp. 718-723
Author(s):  
Yanxin Zheng ◽  
Ying Liu ◽  
Feng Zheng ◽  
Qingsong Song ◽  
Caili Zhang ◽  
...  

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.


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