Friction scratch behavior

Second, the properties of micro/nano friction and wear/ scratch of several representative films are introduced. These films include from organic molecular films, solid films, to multilayers. The experiments were designed reasonably to understand the behaviors of micro/nano friction and wear of the films. The sample preparation methods were also de-... 

Such behavior is important to the understanding of frictional phenomena. It has been known since Amontons ° in the 17th century that friction, the force required to slide one solid over another, increases in proportion to the load pressing the solids together. This is clearly inconsistent with the Hertz equation for contact area. In the Hertz case, the contact diameter increases with thus the contact area increases with and therefore the friction force should also increase with, at odds with the Amontons observations. However, the behavior shown in Fig. 9.9(b), after sliding causes scratching of the surfaces, is consistent with Amonton s Law. The contact size increases with so that the contact area, and therefore friction, is then proportional to load... 

With these complications in mind, research in this area has blossomed rapidly. Two main foci of research in this area are on (1) how external conditions (such as levels of loadings, the use of different indenters, and scratch rate) and (2) intrinsic materials properties (such as modulus and crystallinity) affect the tribological behaviors of the polymers. Apart from examining the scratch resistance of polymers, a closely related quantity which is of interest would be changes in coefficient of friction. Studies relating mechanical properties (3-5,9,36,71,75,76), deformation patterns (18,33,63,71,77-81), fabrication process (3,5,35,72,77,82-86) with respect to experimental parameters, snch as temperature (18), loading effect (24,71,72,87-96), indenter geometry (21,33,75,82,95,97), and scratch velocity (21,56,57,59,64,65,96,98) have been carried ont. In addition, scratch maps for different polymers have been produced (32,33), and various scratch resistance properties estimated (33,37,56,58,59,99). 

Micro-scale scratching of bulk Si by Bhushan and co-workers (1995) showed similar behavior to our scratch results on the unimplanted Si wafer. Using a much smaller probe (conical diamond with 1 p,m end radius) they observed (from friction... 

Determination of scratch resistance is one of the most important aspects of tribology of materials, together with friction and wear. As discussed before [1 - 3], polymer tribology is much more difficult than that of metals. Due to the gradual replacement of metal parts by polymeric ones, the need to understand tribological behavior of polymers is increasing. 

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