**Author details**

Irfan Celal Engin *Afyon Kocatepe University, Engineering Faculty, Department of Mining Engineering, Afyonkarahisar, Turkey* 

#### **8. References**

206 Tribology in Engineering

surface.

**Author details** 

Irfan Celal Engin

*Afyonkarahisar, Turkey* 

very few of the scratches are formed as a result of cutting of material in the shape of chip (Samuels, 1971). Abrasive grain grooves on contact points on material surface mostly by breaking through and friction but it removes small amount of material. Very few of them

Rapid material wear is ensured by applying high loads and low decreasing speed in proportion to high amounts of cutting points, namely by low wear speed of sandpaper. These factors ensure high abrading speed and prevent formation of smooth and shiny

Another intended purpose of sandpaper and cloth is polishing. Mechanism in polishing process is in fact very similar to abrading. It can be said that force affecting each abrasive grain determines depth and width of scratches on the surface of basic material. So, in order to make polishing operations on abraded surfaces, very low loads should be applied on abrasive grain and abrasive grain's height should be very low. Although sandpaper is used in the first step of polishing that is made with sandpaper, polishing cloth (Figure 23) is used

**Figure 23.** Mechanical polishing mechanism of abrasive grain that is clung on the polishing cloth fibre

As can be seen in Figure 23, abrasive grains in polishing cloth is inside the fibers of cloth. Grains affect on the material surface only with elastic force and ensure the creation of

narrower and shallow scratches. In this way, shinier surfaces are achieved.

*Afyon Kocatepe University, Engineering Faculty, Department of Mining Engineering,* 

create chips with grating movement and this is more effective in removing material.

in the last step in order to lessen the scratch depth and form shinier surfaces.


[20] Williams J.A., 1994, Engineering Tribology, Oxford University Press, New York, pp. 167-199.

**Chapter 11** 

© 2013 Kajdas, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

© 2013 Kajdas, licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**General Approach to Mechanochemistry** 

**and Its Relation to Tribochemistry** 

**1.1. Compact information on the considered disciplines** 

Mechanochemistry and tribochemistry disciplines are of particular importance for fundamental research and tribology engineering practice. They relate to specific coupling of physical and chemical phenomena leading to initiation of heterogeneous chemical reactions

Chemical reactions in solids initiated by mechanical action had been considered for a long period of time [1]. From the viewpoint of terms, mechanochemistry and tribochemistry may be compared with terms: physical chemistry and chemical physics. In the latter term physics is first and chemistry second. In tribochemistry, friction (tribos) is the first. Since mechanics includes friction, tribochemistry should be included in mechanochemistry. Reviews on mechanochemistry [2,3] show Matthew Carey Lea as the first systematic researcher on the

Mechanochemical reactions are clearly distinct from those of thermochemical ones. To initiate thermochemical reactions an adequate heat amount has to be supplied to overcome

Mechanical interaction of a solid-solid enables chemical reactions to be initiated by lower

Even a very high calculated 'flash temperature' is short-lived, thus, it rather cannot initiate chemical reactions by heat. Reference [4] demonstrates that high local temperatures generated by friction at the contacts between rubbing surfaces can evolve thermionic activity, likely to be short lived and random. These localized, dynamic regions of intense

Additional information is available at the end of the chapter

Czesław Kajdas

**1. Introduction** 

due to mechanical action.

the activation energy.

chemical effects of mechanical action.

activation energy than regular thermochemical reactions.

thermionic emission can act as catalytic sites for chemical activity.

http://dx.doi.org/10.5772/50507
