Contact Area as a Critical Determinant in the Tribology Of Metal-on-Polyethylene Total Joint Arthroplasty

2005 ◽  
Vol 128 (1) ◽  
pp. 113-121 ◽  
Author(s):  
Daniel Mazzucco ◽  
Myron Spector

The effects of contact area and contact stress on friction and wear of polyethylene-metal articulation were evaluated using a bidirectional pin-on-disk apparatus. A doubling of the contact area under fixed loading conditions led to a 50% increase in the coefficient of friction and a doubling of the wear rate. There appeared to be a relationship between the increase in wear rate and the increase in the coefficient of friction. A model was developed to explain the mechanism by which engagement of asperities results in the increasing wear rate with increasing contact area despite the decreased stress.

Author(s):  
Dan Mazzucco ◽  
Myron Spector

The effects of contact area and contact stress on friction and wear of polyethylene-metal articulation were evaluated using a bi-directional pin-on-disk apparatus. A doubling of the contact area under fixed loading conditions led to a 50% increase in the coefficient of friction and a doubling of the wear rate. There appeared to be a relationship between the increase in wear rate and the increase in the coefficient of friction. A model was developed to explain the mechanism by which engagement of asperities results in the increasing wear rate with increasing contact area despite the decreased stress.


2001 ◽  
Vol 16 (12) ◽  
pp. 3567-3574 ◽  
Author(s):  
Xiaoling Zhang ◽  
W. Lauwerens ◽  
L. Stals ◽  
Jiawen He ◽  
J-P. Celis

The fretting wear of sulphur-deficient MoSx coatings with different crystallographic orientations has been investigated in ambient air of controlled relative humidity. The coefficient of friction and the wear rate of MoSx coatings sliding against corundum depend not only on fretting parameters like contact stress, fretting frequency, and relative humidity, but also strongly on the crystallographic orientation of the coatings. For randomly oriented MoSx coatings, the coefficient of friction and the wear rate increased significantly with increasing relative humidity. In contrast, basal-oriented MoSx coatings were less sensitive to relative humidity. The coefficient of friction of both types of MoSx coatings decreased on sliding against corundum with increasing contact stress and decreasing fretting frequency. A correlation between dissipated energy and wear volume is proposed. This approach allows detection in a simple way of differences in fretting wear resistance between random- and basal-oriented MoSx coatings tested in ambient air of different relative humidity.


Lubricants ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 25 ◽  
Author(s):  
Emad Omrani ◽  
Pradeep Menezes ◽  
Pradeep Rohatgi

The tribological behavior of graphene and graphite as additives in canola oil was investigated with a pin-on-disk tribometer. The wear surfaces of the aluminum pins lubricated with the additive-containing canola oil were analyzed by scanning electron microscopy (SEM). It was found that graphene and graphite as additives in oil show a lower coefficient of friction and wear rate in comparison with neat canola oil. The graphene sheets are more effective than graphite flakes to reduce friction and wear. In addition, there is a proper concentration where the coefficient of friction (COF) and wear are in minimum value. The optimal concentration of the additive in canola oil is about 0.7 wt %. Therefore, the load-carrying capacity and antiwear ability of the lubricating oil are improved. Moreover, the worn surface of aluminum pins is smother in the presence of solid lubricant rather than neat oil.


Author(s):  
Ming-xue Shen ◽  
Bo Li ◽  
De-hui Ji ◽  
Xiao-Rong He ◽  
Xiu-zhou Lin ◽  
...  

This study focuses on the tribological characteristics of polytetrafluoroethylene rubbing against 316L stainless steel in the presence of various Al2O3 abrasive particles. The ranges of the contact stresses and abrasive sizes were 2.50–5.01 MPa and 2.0–230 µm, respectively. The evolution of the coefficient of friction, abrasive invasion behavior and damage characteristics on worn surfaces, and the transformation of damage mechanisms under different contact stresses are summarized. Results demonstrate that contact stress exerts a considerable effect on abrasive invasion behavior, the coefficient of friction trends become complicated at low contact stress. With decreasing particle sizes under a contact stress of 2.50 MPa, the wear failure changes from two-body wear to three-body wear, or two wear behaviors exist simultaneously. As contact stress increases, the wear mechanism is gradually simplified. The particle size threshold that causes the change of the wear mechanism is also gradually reduced. The wear rate of polytetrafluoroethylene has no linear relationship with abrasive size, whereas wear increases with contact stress. Under 2.50 MPa conditions, the particles easily invade the tribo-interface in the friction process, thus increasing the wear rate of the metallic counterpart. In addition, with increases contact stress, the polytetrafluoroethylene material transfers to the counterface, and local adhesion occurs. When the contact stress is increased to 5.01 MPa, polytetrafluoroethylene even shows an obvious creep.


2015 ◽  
Vol 642 ◽  
pp. 19-23
Author(s):  
Shang Guan Bao ◽  
Yi Fan Wang ◽  
Zhen Hai Yang ◽  
Yong Zhen Zhang ◽  
Yue Chen ◽  
...  

Using C/C composite and chrome bronze as a friction couple, the frictional wear properties of C/C composite with electric current is studied in this paper. The results have shown that current, velocity and load are important factors to affect the frictional wear properties of C/C composite with electric current. Wear rate of C/C composite increases with the increase of arc energy .The coefficient of friction and the wear rate increase with the increase of velocity when the electric current is constant of 100A. The coefficient of friction increases but the wear rate decreases with the increase of load when the electric current is constant at 100A. The coefficient of friction decreases but the wear rate increases with the increase of current when the load is constant of 80N. Comparing with no electric current, the coefficient of friction of C/C composite with electric current decreases but the wear rate of that increases obviously. The wear mechanism of C/C composite is mainly of electric wear caused by arc erosion under the condition of current-carrying.


2012 ◽  
Vol 585 ◽  
pp. 569-573 ◽  
Author(s):  
S.R. Chauhan ◽  
Sunil Thakur

In this paper the friction and wear characteristics of vinylester and vinylester composites have been investigated under dry sliding conditions for different applied normal load, sliding speed and sliding distance. The experiments have been carried on a pin on disc arrangement at normal room temperature conditions. The influence of friction and wear parameters like normal load, speed, sliding distance and percentage of filler content on the friction and wear rate has been investigated. In this study, a plan of experiments based on the techniques of Taguchi was performed to acquire data in a controlled way. An orthogonal array L27 (313) and Analysis of variance (ANOVA) were applied to investigate the influence of process parameters on the coefficient of friction and sliding wear behaviour of these composites. The Taguchi design of experiment approach eliminates the need for repeated experiments and thus saves time, material and cost. The results showed that with increase in the applied normal load and sliding speed the coefficient of friction and specific wear rate decreases under dry sliding conditions. It is also found that a thin film formed on the counterface seems to be effective in improving the tribological characteristics. The results showed that the inclusion of cenosphere as filler materials in vinylester composites will increase the wear resistance of the composite significantly.


Author(s):  
Mohamad Nordin Mohamad Norani ◽  
Mohd Fadzli Bin Abdollah ◽  
Muhammad Ilman Hakimi Chua Abdullah ◽  
Hilmi Amiruddin ◽  
Faiz Redza Ramli ◽  
...  

This study intends to analyse the coefficient of friction and wear properties of the acrylonitrile butadiene styrene polymer by determining the optimal parameters for 3D printing. The pin specimens were produced using the fused filament fabrication 3D printing. Response surface methodology is used for the multivariate analysis, and Box–Behnken Design is the chosen symmetrical design method. Changes to the dependent variables, coefficient of friction and wear rate, were analysed as a function of the nozzle temperature, layer height and printing pattern. The coefficient of friction and wear rate were measured using a pin-on-disc tribometer. A good agreement between the modelled and measured values of coefficient of friction and wear rate was observed. The study suggests that layer height affecting coefficient of friction and wear rate most significantly. It is determined that a layer height of 0.10 mm and a nozzle temperature of 234℃ using the triangle printing pattern is the optimal set of combination to minimise coefficient of friction and wear rate.


2015 ◽  
Vol 642 ◽  
pp. 179-183
Author(s):  
K.A.H. Al Mahmud ◽  
M.A. Kalam ◽  
H.H. Masjuki ◽  
H.M. Mobarak

Currently diamond like carbon (DLC) coatings application for automotive components is becoming a favorable strategy to cope with new challenges faced by automotive industries. DLC coating is very effective to lower the coefficient of friction and wear rate, which in turn could improve fuel efficiency and durability of the engine components. Commercially available fully formulated lubricating oils are specially produced to enhance the lubrication of ferrous materials. Therefore, nonferrous coating (DLC) interaction with commercial lubricating oil needs to be investigated. In this current investigation, coefficient of friction and wear rate were investigated by ball on plate tribo testing machine at different temperatures in the presence of SAE 40 lubricating oil. At high test temperature coefficient of friction decreases, however wear rate increases for the a-C:H coated plate, however, steel/steel contact shows opposite trend of coefficient of friction and wear rate change.


1986 ◽  
Vol 108 (4) ◽  
pp. 514-521 ◽  
Author(s):  
H. Ishigaki ◽  
I. Kawaguchi ◽  
M. Iwasa ◽  
Y. Toibana

An investigation was conducted to determine the friction and wear characteristics of hot-pressed silicon nitride. Sliding produced wear debris and a damaged surface. The physical and crystallographic morphology of surfaces was compared with that of diamond ground surfaces. Wear tests were done with pin-on-disk apparatus at a load of 10N with various sliding speeds to 780 mm/s, and in four different environments which included in dry nitrogen, in air at humidities of 50 percent RH and 90 percent RH, and in distilled water. The results of the wear experiments indicated that residual α-silicon nitride was transformed into β-silicon nitride. Adsorbed water appeared to enhance plastic flow of the surface and reduced both the wear rate and friction. A second investigation was conducted to correlate the coefficient of friction with the fracture toughness of silicon nitride, silicon carbide, aluminum oxide and zirconium oxide. The friction experiments were done in reciprocating sliding, using spherical diamonds. Two tip radii, 0.005 mm and 0.1 mm were used over a range of load of 0.1 to 3N and a speed of 0.17 mm/s. The coefficient of friction was found to be inversely correlated with fracture toughness of all four ceramics in several conditions. Frictional anisotropy was also observed in the hot-pressed silicon nitride.


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