Pin-on-disk configuration

Bermudez et al. [67] studied the tribological properties of PC+0.5%ZnO+1.5% IL composites and showed an 80% friction reduction and wear reduction of nearly two orders of magnitude with respect to PC+0.5% ZnO. They then investigated ILs as an effective lubricant additive of epoxy resin under the pin-on-disk configuration and showed a friction reduction higher than 50% and a wear rate reduction of two orders of magnitude for epoxy resin (RE)+1.5% IL with respect to the neat Re and Re+0.5% ZnO [68], The ability of ILs to act as lubricant additives of polymers under sliding conditions can thus be confirmed by the above report. 

Figure 8.9. Value of coejjicient of friction and of specific wear rate for different ceramic couples in the pin on disk configuration [IWA 86]...

Classical, macroscopic devices to measure friction forces under well-defined loads are called tribometers. To determine the dynamic friction coefficient, the most direct experiment is to slide one surface over the other using a defined load and measure the required drag force. Static friction coefficients can be measured by inclined plane tribometers, where the inclination angle of a plane is increased until a block on top of it starts to slide. There are numerous types of tribometers. One of the most common configurations is the pin-on-disk tribometer (Fig. 11.6). In the pin-on-disk tribometer, friction is measured between a pin and a rotating disk. The end of the pin can be flat or spherical. The load on the pin is controlled. The pin is mounted on a stiff lever and the friction force is determined by measuring the deflection of the lever. Wear coefficients can be calculated from the volume of material lost from the pin during the experiment. 

The pin-on-disk tribometer can be modified by replacing the rotating disk motor with a one-directional reciprocating table as shown in Fig. 2.19. This arrangement reproduces the reciprocating motion typical in many real-world mechanisms. The configuration of... 

Experimental techniques commonly used for assessing the tribological behavior have resorted to pin on disk, disk on disk, ball on disk, or even cylinder on cylinder configurations. Figure 8.9 shows the results obtained for different dense ceramics couples through the pin on disk method, under a load of 1 kg, with an average relative contact speed of 0.18 ms f... 

It is still questionable whether the criteria to classify wear particles could be applied to different wear situations. Relations between processes of particle formation and particle shapes in the ball-on-disk experiment, and in most of normal wear situations, are not so simple and clear as those in the dual-pin/disk configuration. It is necessary to clarify any deviations between them, and to find how to incorporate the deviations in the classification of wear particles. Any progress in this respect will be useful in condition monitoring as well as in exploring mechanisms of wear. 

Which one or combination of these motions are actually simulated (or occm) depends on whether the UHMWPE acts as a pin or disc, the shape of each, and whether either pin and/or the disk moves and how. A wide spectrum of POD test machines have therefore been used in a multitude of configurations from the very simple (e.g., linear reciprocal) to the highly sophisticated and flexible, such as... 

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