Activity of Rubbing Surfaces

There are various surface techniques, eg., optical interferometry high frequency capacitance and resistance method, which demonstrate the build up of the physically and chemically reacted film during boundary lubrication in scuffing reactions (Anghel et al., 1997 Dowson et al., 1996 Smalley and Cameron, 1996). 

Exoelectrons are known to be emitted from nascent or fresh solid surfaces by mechanical action such as abrasion, cutting, surface fatigue, wear, forming and so on. There are two types of EE associated with dark emission termed triboemission and after emission (Kajdas, 1985a, 1989 and 1994 Nakayama and Hashimoto, 1991 and 1992 Nakayama et al., 1992 and 1995 Thiessen, 1965). 

Exoemission = Triboemission + After-emission (emitted particles) (negative ions, radicals, (electrons) 

Triboemission time is extremely short while after-emission time is much longer. The enhanced surface activity caused by rubbing processes produces exoelectrons emission, catalytic and structural factors, increased surface temperature, and pressure (Rowe and Murphy, 1974). 

When surfaces of tribological systems are involved in the mechanical activity of rubbing, direct reactions of surface adsorbed films with solid surfaces take place. The mechanically activated clean surface (nascent surface) of the metals and alloys is extremely reactive. Tribofilm formation is caused by the interaction between the metal (M, substrate) nascent surface under high energy and chemisorbed molecules of additive (adsorbate) (Buckley, 1981). 

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Catalytic activity of rubbing surfaces (a) By reference to Table 5.5, find the metal hydroxides, oxides and nitrides that illustrate their highest exoelectrons emission intensity (I, cps), (b) Calculate the tribochemical energy (TribEn) TribEn = (AHf - WF) for the listed compounds and correlate them with measured exoelectrons emission intensity (I, cps). Explain differences. 

The next chapter is a review of current practice in lubrication of internal combustion engines and lubricant design. The role of individual lubricant components and their use in mineral and synthetic formulations is covered. This is followed by a discussion of the tribochemical effects of additive interactions. The heart of the manuscript is chapters, "Tribochemical nature of antiwear film , "Surface tribochemistry and activated processes", and "Analytical techniques in lubricating practices". Topics covered include tribofilm formation, organomolybdenum compounds in surface protection, catalytic activity of rubbing surfaces, introduction of some techniques for evaluation of tribofilms composition and analytical techniques for evaluation of lubricant degradation. Examples of the application of basic concepts are introduced, eg., acidity and basicity in the process of lubricant deterioration. 

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