Research on Ultrafine PTFE Particles with Grease Tribological Properties

2011 ◽  
Vol 194-196 ◽  
pp. 454-457
Author(s):  
Zhen Jiang Ma ◽  
Ji Hui Yin ◽  
Yang Jiang

This article presents a research on friction and wear properties of titanium composite lubricating grease containing ultrafine PTFE particles by using scanning electron microscopy to observe surface morphology of the worn steel balls and EDS to analysis the main elements in the worn surface of steel ball. The results show that the compound titanium grease with 3% ultrafine PTFE has the best wear and friction reduction properties. Its friction coefficient decrease about 25.5%, the diameter of wear scar decrease about 23.2%. The appropriate amount of PTFE particles go into the frictional surface with the grease, form the PTFE particle layer on the frictional surface, which reduces the direct contact of metal to metal, effectively reduces the friction and wear.

2012 ◽  
Vol 476-478 ◽  
pp. 566-569
Author(s):  
Bao Guo Yuan ◽  
Hai Ping Yu ◽  
Ping Li ◽  
Gui Hua Xu ◽  
Chun Feng Li ◽  
...  

The effects of hydrogen on friction and wear properties of Ti–6Al–4V alloy sliding against GCr15 steel were investigated through dry sliding friction and wear tests in atmosphere at room temperature. Wear mechanism was determined by studying the morphology and chemical element of worn surface using SEM and EDS. Results show that friction coefficient decreases slightly and wear rate increases after hydrogenation. Wear mechanism is discussed.


2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Zhen-yu Wang ◽  
Jie Wang ◽  
Yun-hai Ma

Corn stalk fibre reinforced nonasbestos environment-friendly friction composite materials have been fabricated, and their physical, mechanical, and tribological properties are characterized. The tribological properties of the friction composites were evaluated following GB5763-2008 norms on a constant-speed-type friction tester. The experimental outcome reveals that the content of corn stalk fibre has a noteworthy impact on the tribological, mechanical, and physical properties of the friction composites. Specifically, the friction composite with a content of 7% exhibited excellent friction and wear properties. The worn surface morphology of friction composites was further investigated using a scanning electron microscope. It was found that the corn stalk fibre content greatly affected the tribological properties of the friction composites.


Author(s):  
F. Vos ◽  
L. Delaey ◽  
M. De Bonte ◽  
L. Froyen

Abstract An alternative production route to obtain thermally sprayed self-lubricating ceramic coatings is proposed and microstructural, friction and wear properties of these coatings are discussed. A preliminary powder treatment shows to induce a higher degree of homogeneity compared to conventionally deposited composite coatings, offering some perspectives for a further improvement of the lubricating and wear properties. This approach is illustrated using CaF2 as a solid lubricant dispersed in a Cr2O3 matrix, where the high melting point of the latter (Tm{Cr2O3} =2460°C) necessitates plasma spraying as deposition technique. The microstructure of the coatings is evaluated by a metallographic study of sections perpendicular and parallel to the substrate surface. Wear and friction behaviour is evaluated using reciprocating wear test Wear tracks are analysed by means of laser profilometry. The results are discussed in relation to test and production parameters. Test temperature as well as solid lubricant concentration predominantly affects the wear and friction properties. Using a surface temperature of 400°C a friction coefficient of 0.25 and a wear volume of 37*103 µm3 after 10.000 cycles are obtained for a coating containing 16 vol.% of CaF2.


2012 ◽  
Vol 538-541 ◽  
pp. 1920-1923
Author(s):  
Yu Lin Qiao ◽  
Shan Lin Yang ◽  
Yan Zang ◽  
Xin Yu Dong ◽  
Qing Sheng Cui

The friction and wear properties of GCr15/45# steel frictional pairs lubricated by n- Al2O3 additives under ultrasonic vibration or not were studied. The scanning electron microscope(SEM), X-ray photoelectron spectroscopy(XPS) and energy dispersive spectrometer (EDS) were carried out to analyse the wear scar surface. The effect mechanism of ultrasonic vibration on friction pairs was discussed. The results indicated that ultrasonic vibration could decrease the friction and wear of GCr15/45# friction pairs, when the content of n-Al2O3 was 0.5wt%, the effect of ultrasonic vibration on friction pairs was most obvious. The friction coefficient, wear volume and wear scar depth under ultrasonic vibration decreased 10%, 34% and 13%, respectively. The friction reduction and anti-wear mechanism of n-Al2O3 was single “micro ball bearing” without ultrasonic vibration, and it changed to “micro ball bearing” and adsorption penetration film with ultrasonic vibration, so the friction coefficient and wear volume was reduced.


2008 ◽  
Vol 368-372 ◽  
pp. 961-963
Author(s):  
Hou An Zhang ◽  
Xiao Pin Hu ◽  
Wei Cheng Tan ◽  
Cun Shi

MoSi2 was prepared by SHS, and then pressed under 300 MPa at room temperature and sintered at 1600 °C for 1 h in a vacuum furnace. The tribological properties of MoSi2 against Al2O3 in the temperature range from 700°C to 1100 °C were investigated. Microphotographs and phases of the worn surface of MoSi2 were observed by SEM and XRD. Results showed that MoSi2 has well friction and wear properties below 900 °C. When temperature rises from 900 °C to 1000 °C, wear rate of MoSi2 is raised by 20.8% which is attribute to the change of wear mechanism. The main wear mechanisms of MoSi2 are adhesion and oxidation at high temperatures. When over 900 °C, because of ductile - brittle transition characteristic of this material, plastic deformation and fracture are also found on the worn surface of MoSi2. This leads to the high wear rate of MoSi2.


2013 ◽  
Vol 747-748 ◽  
pp. 152-157 ◽  
Author(s):  
Shu Fa Chen ◽  
Cheng Long Feng ◽  
Jin Yang ◽  
Jin Song Chen

In this study, the dry sliding wear behavior of Ni-based self-lubricating wear-resistant coating was characterized under various loads at 300 . Morphologies and compositions of the worn surface were analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The experimental results showed that with the increase of load, both the frictional coefficient and wear rate decreased firstly, then slightly increased. A small amount of debris dispersed on the worn surface of the coating under low load (2 N). Since the effects of oxide layer and lubricant particles spreading onto the worn surface, the coating exhibited superior friction, and improved the wear properties under moderate load (5 N). As the load further increased, till up to 10N, the worn surface started to appear some shallow grooves and craters. This was contributed to the dispersion of carbides and lubricant particles.


2016 ◽  
Vol 94 ◽  
pp. 176-186 ◽  
Author(s):  
Zhiwei Wu ◽  
Fei Zhou ◽  
Kangmin Chen ◽  
Qianzhi Wang ◽  
Zhifeng Zhou ◽  
...  

2014 ◽  
Vol 1058 ◽  
pp. 56-60
Author(s):  
Hai Chao Zhao ◽  
Yu Lin Qiao ◽  
Yan Zang ◽  
Qing Zhang

Different thickness multi-layer graphene were prepared by the method of liquid ultrasonic stripping and characterized by XRD, SEM and TEM. Friction and wear properties of graphene liquid dispersing system were investigated using an Multi-functional reciprocating friction and wear tester in ambient condition. Results indicate that the graphene were in thickness of 10nm-100nm. Multi-layer graphene showed good anti-friction and anti-wear properties as paraffin liquid additives. Multi-layer graphene liquid dispersing system had the best tribological properties with 20N and 0.01wt%, and the average friction coefficient was 0.129, and the wear mass was 4.12×106μm3, reduced by 21.34% and 41.14% than paraffin liquid. The reason is that Multi-layer graphene could adsorb on the worn surface and form solid adsorption layer, which maked the friction and wear reduce.


2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Dongdong Gu ◽  
Jiubin Jue ◽  
Donghua Dai ◽  
Kaijie Lin ◽  
Wenhua Chen

The friction and wear properties of in situ Al-matrix composites prepared by selective laser melting (SLM) were evaluated on a ball-on-disk tribometer by sliding against GCr15 steel at room temperature. The influence of the applied load, sliding speed, and long-time continuous friction on the friction and wear properties of Al-matrix composites was systematically investigated. It showed that the wear rate and coefficient of friction (COF) increased when the applied load increased, due to the higher contact stress and larger extent of particle fracturing. As the sliding speed increased, the elevated rate of the formation of Al-oxide layer and the transfer of Fe-oxide layer from the counterface to the worn surface led to a significant reduction in wear rate and COF. As the sliding distance prolonged, the worn surface successively experienced the adhesive wear, the abrasive wear, the particle fracturing and crack nucleation, and the delaminated wear. The above processes were repeated on each exposed fresh surface, resulting in the fluctuation of COF. In the later stage of wear process, a large amount of oxides were produced on the worn surface, caused by the long-time accumulated frictional heat, which reduced the fluctuation of COF. The wear mechanisms of SLM-processed Al-matrix composite parts under various loads were dominated by abrasive wear and oxidation wear, whereas the predominant wear mechanisms were oxidation wear and delamination wear at different sliding speeds. For the long-time friction, all of these wear mechanisms were operational.


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