Effects of Nanostructured Additives on Boundary Lubrication for Potential Artificial Joint Applications

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Alice Pendleton ◽  
Prasenjit Kar ◽  
Subrata Kundu ◽  
Sahar Houssamy ◽  
Hong Liang

Water-based fluids containing nanostructured fullerene C60 and 18-crown ether-6 were investigated. The effects of those nanostructured additives on the tribological performance of titanium and its alloys as potential biomaterials were analyzed. Experimentally, tribology tests were conducted using a Ti–6Al–4V ball against a disk made of pure titanium as a simplified model of the material rubbing pair. Lubrication mechanisms were studied by comparing the nanostructures, viscosities, and frictions. Results showed that the fullerene C60 in deionized water provided the lowest viscosity and friction. Crown ether, on the other hand, provided high friction and shear. Our analysis indicated that the fullerene was weakly interacted with water compared with the crown ether, resulting in an extended low friction in the boundary lubrication regime. The crown ether required extra energy in order to slide or roll. This led to a high friction. This finding opens the possibilities for lubrication design and optimization for biological and engineering applications in general.

Langmuir ◽  
2021 ◽  
Vol 37 (5) ◽  
pp. 1743-1759 ◽  
Author(s):  
Kimaya Vyavhare ◽  
Richard B. Timmons ◽  
Ali Erdemir ◽  
Brian L. Edwards ◽  
Pranesh B. Aswath

2021 ◽  
Vol 11 (2) ◽  
pp. 595
Author(s):  
Tatsuhiko Aizawa ◽  
Tomoaki Yoshino ◽  
Yohei Suzuki ◽  
Tomomi Shiratori

A bare AISI420J2 punch often suffers from severe adhesion of metallic titanium as well as titanium oxide debris particles in dry, cold forging of biomedical titanium alloys. This punch was plasma-carburized at 673 K for 14.4 ks to harden it up to 1200 HV on average and to achieve carbon supersaturation in the carburized layer. This plasma-carburized punch was employed in the cold, dry forging of a pure titanium wire into a flat plate while reducing the thickness by 70%. The contact interface width approached the forged workpiece width with increasing the reduction ratio. This smaller bulging deformation reveals that the workpiece is upset by homogeneous plastic flow with a lower friction coefficient. This low-friction and anti-galling forging process was sustained by an in situ solid lubrication mechanism. Unbound free carbon was isolated from the carbon-supersaturated AISI420J2 matrix and deposited as a thin tribofilm to protect the contact interface from mass transfer of metallic titanium.


2012 ◽  
Vol 47 (3) ◽  
pp. 341-347 ◽  
Author(s):  
Caitlin Moore Strobel ◽  
Pradeep L. Menezes ◽  
Michael R. Lovell ◽  
Kurt E. Beschorner

Author(s):  
G. Pennecot ◽  
K. Komvopoulos ◽  
E. S. Yamaguchi

The effectiveness of blends consisting of base oil, some secondary zinc dialkyl dithiophosphate (ZDDP), and different detergents to form antiwear tribofilms on steel surfaces sliding in the boundary lubrication regime was investigated in the temperature range of 105–125°C. The efficacy of the tribofilms formed from these blends was evaluated in terms of contact voltage and wear rate measurements. The best antiwear performance was demonstrated by the tribofilm formed from the blend containing sulphonate detergent. The results of this study provide insight into competing effects between ZDDP and different detergents that affect significantly the antiwear performance of the formed tribofilms.


2008 ◽  
Vol 130 (4) ◽  
Author(s):  
T. Haque ◽  
A. Morina ◽  
A. Neville ◽  
S. Arrowsmith

In recent years, the optimized use of low friction nonferrous coatings under boundary lubrication conditions has become a challenge to meet the demands of improved fuel economy in automotive applications. This study presents the tribological performance of chromium nitride (CrN) coating using conventional friction modifier (moly dimer) and/or antiwear additive (zinc dialkyl dithiophosphate (ZDDP)) containing lubricants in a pin-on-plate tribometer. Using surface analysis techniques such as the atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS), both topographical and chemical analyses of tribofilms were performed. This paper shows that ZDDP and moly dimer both give a positive effect for both low friction and antiwear performance in CrN/cast iron system. Both AFM and XPS analyses give evidence of the formation of ZDDP and moly dimer derived tribofilms on the CrN coating and thus support friction and wear results.


Author(s):  
Wattanapat Kumwannaboon ◽  
Sathaporn Chuepeng ◽  
Cholada Komintarachat

Friction between rubbing pairs plays a key role in operating machines in an efficient approach. In some intended works or occasional circumstances, slipping friction may occur during dry or boundary lubrication. Lubricating mechanical equipment using proper and efficient lubricant agents is tremendously necessary. This work explores the synthesized triacetin as an additive for lubricant under slipping friction between steel rollers and aluminum, brass, copper, and stainless-steel rods under boundary lubrication. The metal surface morphology under the lubricant with 10% triacetin additive covering roughness periphery is investigated by Field Emission Scanning Electron Microscope imaging. In the dry slipping condition, the friction coefficient is lower for the copper-steel pair compared to the aluminum-steel combination. Compared to the absence of triacetin additive, the steel roller combinations with the rod metal specimens undergoing boundary lubrication with 10% triacetin additive in the lubricant can reduce the slipping friction coefficient by up to 49.2% in the case of steel roller and brass rod pair. The quantitative influences of triacetin additive on metal rubbing pair friction coefficients under boundary lubrication are inversely exponential correlated to triacetin additive, varying in the range of 0 to 10% v/v.


2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Yufu Xu ◽  
Jingyuan Yu ◽  
Yinghui Dong ◽  
Tao You ◽  
Xianguo Hu

As a novel layered material, black phosphorus (BP) shows unexpected characteristics in many aspects including tribological application. In this work, BP was prepared through ball milling from red phosphorus (RP). The boundary lubricating properties of the BP nanosheets were investigated on a ball-on-disk tribometer as lubricating additives in polyalphaolefin oil. The micromorphologies, concentration, and composition of the typical chemical elements on the worn surfaces were measured by the 3D laser scanning microscope, scanning electron microscope, and X-ray photoelectron spectrometer, respectively. The results show that bulk BP can be found after RP was milled at 500 rpm for 36 h. The Raman intensity of the BP increased initially and then decreased with the increase in milling time, and the maximum intensity can be obtained at 60 h. The BP nanosheets displayed excellent antifriction and anti-wear performances as lubricating additives in PAO6 oil for steel/steel contact in boundary lubrication regime. The boundary lubrication mechanism of the BP nanosheets is dominated by the physical slippery effect of the laminated nanosheets and the tribofilm on the rubbing surfaces.


Author(s):  
F. Robbe-Valloire ◽  
R. Progri ◽  
B. Paffoni ◽  
R. Gras

Mixed lubrication is usually related to the partition of contacts, and these latter may be divided into two categories. The first includes all asperities working in thin lubricated film (physico-chemical film) conditions. This situation corresponds to local boundary lubrication and is characterised by a local friction coefficient around 0.1. The second category contains all other asperity types. Due to the existence of a thick lubricant films asperities belonging to the second category exhibit a low friction coefficient. The global tribological behaviour for a given contact, however, is function of both categories, since it involves asperities from both categories.


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