THE EFFECT OF GRAPHENE ADDITIVE ON THE TRIBOLOGICAL PROPERTIES OF BIONIC LUBRICANT COMPOSITIONS TESTED BY THE SRV METHOD

Tribologia ◽  
2019 ◽  
Vol 288 (6) ◽  
pp. 47-56
Author(s):  
Jarosław Molenda ◽  
Remigiusz Michalczewski

The aim of the study was to investigate the effect of the addition of graphene dispersion on anti-wear properties of bionic lubricant compositions based on aqueous sodium hyaluronate solutions. Tribological tests were carried out using a SRV tester, enabling the tests to be carried out in conditions of linear oscillating movement of the bullet-shield type association in which the ball was made of aluminium oxide and the disc was made of bearing steel 100Cr6. For research, a 0.5% solution of sodium hyaluronate in water (composition BSS2) was chosen, which was the base to which the graphene additive was introduced. During the main stage of work, three lubricant compositions were tested, i.e., as well as BSS2 solution, into which 0.05% m/m or 0.1% m/m graphene oxide was introduced, respectively. The study allowed the observation of a clear anti-wear effect associated with the introduction of graphene preparations into the hyaluronan base, manifested in a change in the trend of the graph of the coefficient of friction over time. In addition, a reduction in the volume wear of friction node components was found. Based on the analysis of tribological research results, it was found that the anti-wear effect of the lubricant on the friction elements of the steel-ceramic material combination increases with increasing the content of the graphene preparation in the lubricant composition.

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Neha Singh ◽  
Sujeet K. Sinha

Abstract Epoxy with ultra-high molecular weight polyethylene (UHMWPE) and MoS2 fillers was coated on a bearing steel (SAE 52100). Frictional and wear properties of the coated samples in sliding contact were investigated on a pin-on-disc tribometer under a normal load of 10 N and a linear sliding speed of 1 m/s against a bearing steel ball. The optimized coating composition (72 wt% Epoxy + 7 wt% hardener + 18 wt% UHMWPE + 3 wt% MoS2) showed highly improved tribological properties compared to pure epoxy and other epoxy-based composites. There was 75% reduction in the coefficient of friction (COF) in the dry interfacial condition (COF reduced from 0.2 to 0.05) over pure epoxy and 80% reduction with grease as the lubricant. The specific wear-rate of the composite was lower by five orders of magnitude over that of pure epoxy. Other mechanical properties such as hardness, tensile strength, and Young's modulus of the composite showed increments of 86%, 121%, and 43%, respectively, with respect to those of pure epoxy. 2–3 wt% of MoS2 had drastic effects on improving strength and reducing friction and wear of the composites. For dry sliding, initial abrasive and adhesive wear mechanisms led to transfer film formation on the steel counterface, and the shearing was mainly within the transfer film. For the grease-lubricated case, a thin layer of grease helped in easy shearing, and the transfer film formation was avoided. This epoxy-based composite will have applications as tribological coatings for journal bearings.


2021 ◽  
Vol 1032 ◽  
pp. 163-171
Author(s):  
Jing Guan ◽  
Xue Ting Jiang ◽  
Xing Cheng ◽  
Feng Yang ◽  
Jing Liu

The surface of Ti6Al4V alloy was rapidly carburized by high-frequency electromagnetic induction heating under vacuum. The microstructure and hardness of the carburized layer were studied. The wear properties of the carburized layer were tested at 50, 100 and 200 rpm using the end face friction and wear device, and the wear mechanism was analyzed. The results show that the TiC strengthening phase was formed on the surface of Ti6Al4V alloy after high-frequency induction carburization, and the surface grains were refined. The surface hardness reaches 1116 HV0.25, but the brittleness of the carburized layer increases with increasing temperature. The amount of wear was reduced by 54% at 100 rpm. The roughness of the wear scar was reduced from 3.26 μm to 2.28 μm of Ti6A14V alloy matrix. The coefficient of friction and wear rate increases with increasing speed. The wear mechanism was transformed from adhesive wear and oxidative wear of the substrate to abrasive wear after carburizing.


Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 1127-1138 ◽  
Author(s):  
Fengjun Wei ◽  
Bingli Pan ◽  
Juan Lopez

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.


Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 179 ◽  
Author(s):  
Jinchi Tang ◽  
Xiongfeng Hu ◽  
Fuqiang Lai ◽  
Xiaolong Guo ◽  
Shengguan Qu ◽  
...  

In this paper, the fretting wear properties of 20CrMnTi steel, a common material for a rocker bracket, was discussed for the first time after it was suffered carburizing treatment. Subsequently, the fretting wear behaviors of virgin, quenched, and carburized states were studied. The effect of loads (corresponding to different engine power output) and reciprocating frequencies (corresponding to different engine speed) on wear behaviors and mechanisms of carburized specimen were further discussed. The results showed that the coefficient of friction (CoF) and wear volume loss (WVL) of the carburized specimens were significantly lower than that of virgin and quenched states. During the wear test, the surface CoF decreased gradually with the increase of applied load, while the linear correlation trend was not observed with the increase of fretting frequency as it showed an increase first and then a decrease. It was observed that the WVL increased gradually with the increase of load and frequency. With an increase of the load, the wear mechanism gradually deteriorated from the initial adhesive wear to the mixed wear mechanism. When the load was high, the oxidative wear became more severe. However, no significant effect of frequency was observed on the wear mechanism.


2019 ◽  
Vol 25 (4) ◽  
pp. 383-393 ◽  
Author(s):  
Libin ZANG ◽  
Yong CHEN ◽  
Lixin RAN ◽  
Yang ZHENG ◽  
Kai LI ◽  
...  

Surface modification is an important method to improve the contact fatigue life of transmission parts. The preparation of high performance coating with good tribological properties on the gears and bearings has become the research trends. This paper presents graphite/MoS2 composite spray and manganese phosphate conversion coating prepared on the AISI52100 steel surface and investigates their anti-fatigue mechanism. The tribological properties of the modified layers were studied using a SRV-IV multifunctional friction and wear tester. The microstructure and interfacial components of the coating and wear surfaces were analyzed by SEM and EDS, respectively. The surface morphology and phase composition of the coating were evaluated through laser 3D microscopy and XRD analyses, respectively. Both modified layers showed good anti-friction and anti-wear properties. The friction coefficients of the surfaces modified by manganese phosphate coating and graphite/MoS2 decreased by 7 % and 14 %, respectively, and the corresponding extreme pressure properties increased by 11 % and 55 %, respectively. But the mechanism of anti-fatigue wear and the corresponding interfacial phenomena of the surface modification of the graphite/MoS2 composite spraying layer is different from those of manganese phosphate coating. The hard-ceramic particles with graphite and MoS2 are sprayed on the substrate to obtain the surface hardening layer, resulting in higher wear resistance. The graphite and MoS2 modified layer can greatly reduce the friction coefficient and improve the lubrication performance on the surface. Manganese phosphate coating serves as a chemical soft coating and is filled with rough corrugated caused by surface processing, which induces an ideal meshing surface after initial friction phase. The obtained hole-shaped structure and "infiltration" role contribute to the storage of lubricants and thus improves the lubrication performance.


2017 ◽  
Vol 266 ◽  
pp. 155-164
Author(s):  
Chao Feng ◽  
Yi Xie ◽  
Zhong Wu

In this study, attempt has been made to investigate the effect of SiC particles on the friction and wear properties of Ni/SiC composites manufactured by electrodeposition, especially for the composites with high-temperature treatment.For this purpose, α-Al2O3 was coated on the surfaces of SiC particles by sol-gel technology to inhibit interfacial reaction of SiC and nickel at high temperature. Both of the Ni/α-Al2O3-coated SiC (Ni/CSp) and Ni/uncoated SiC (Ni/UCSp) composites were treated at 600 °C to study the resulting wear behaviour. The results indicated that with heat treatment at 600 °C, the Ni/CSp composite had better tribological properties than the Ni/UCSp composite. It was proved that the uncoated SiC particles have reacted completely with nickel leaving many defects, while the coated SiC particles still remained in the Ni/CSp composite hardening the nickel matrix and supporting the counterpart, thus improving the wear resistance of Ni/CSp composite with relatively low friction coefficient and wear mass loss compared to the Ni/UCSp composite.


Author(s):  
Rajaganapathy C ◽  
Vasudevan D

In this paper, an attempt was made, to evaluate the tribological performance of Jatropa oil with addition of nanoparticles, on wear reduction in Al 6082 and it was compared with SAE20W40 engine oil. Experiments were conducted with pure Jatropa oil with different weight percentage of TiO2 nanoparticles such as 0%, 0.1%, 0.3% and 0.5%. The coefficient of friction and specific wear rate of the Al specimens were found by using pin on disc tribo-meter as per ASTM G99 standards, at constant speed of 1m/s using different loads such as 20N, 40N and 60N. The experimental results indicated that the addition of TiO2 with Jatropa oil indicated good friction reduction and anti-wear properties, compared to SAE20W40 engine oil. The lubricant viscosity and thermal conductivity were measured using Redwood viscometer and Transient hot wire method. Surface analysis was done using scanning electron microscopy to the study surface morphology of pin material. Surface examination revealed that TiO2 Nanoparticles lead to smoother worn surfaces than commercial Engine oil SAE20W40.


RSC Advances ◽  
2015 ◽  
Vol 5 (66) ◽  
pp. 53326-53332 ◽  
Author(s):  
Jyotiranjan Ota ◽  
S. K. Hait ◽  
M. I. S. Sastry ◽  
S. S. V. Ramakumar

The stable dispersion of graphene in formulated lubricating oils reduces the coefficient of friction and significantly improves heat dissipation from the system owing to its higher thermal conductivity.


2013 ◽  
Vol 834-836 ◽  
pp. 23-28 ◽  
Author(s):  
Jun Ma ◽  
Chong Hai Xu ◽  
Ming Dong Yi ◽  
Guang Chun Xiao ◽  
Xing Hai Wang

Ti (C,N)/ZrO2/WC nanocomposite cermet die materials were fabricated by vacuum hot pressing process, the materials have better comprehensive mechanical properties. The friction and wear properties of Ti (C,N)-based nanocomposite cermet die materials were studied, and the worn surfaces microstructure were observed and analysed by SEM and XRD. The experimental results showed that when the rotate speed was higher, the coefficient of friction of the developed cermet die material, which is 0.3-0.4, was lower than that without the addition of nanoZrO2 and micrometer WC. The main wear mechanisms were abrasive wear, oxidation wear and adhesive wear.


1999 ◽  
Vol 121 (2) ◽  
pp. 294-300 ◽  
Author(s):  
Hozumi Goto ◽  
Shunji Omori

Pin-on-disk unidirectional sliding friction and wear experiments for an aluminum alloy impregnated carbon composite in contact with a bearing steel were carried out at various levels of contact load in wet and dry air. The aluminum alloy impregnated carbon composite exhibits better friction and wear characteristics than the matrix materials, aluminum alloy and graphite in wet air. The coefficient of friction and wear rate decrease, especially at high loads in wet air. Graphite, together with metallic and oxidative wear particles, adheres to the disk sliding surface of the bearing steel, resulting in the formation of compacted, uniform surface films. The films prevent metal-to-metal contact, achieving a good sliding friction and wear condition.


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