# Mechanical finishing

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Mechanical finishing is a big and important industry,it encompasses many processes that alter the surface of a manufactured item to achieve a certain property: improve appearance, adhesion or wettability, solderability, corrosion resistance, tarnish resistance, chemical resistance, wear resistance, hardness, modify electrical conductivity, remove burrs and other surface flaws, and control the surface friction. In particular, mechanical finishing is done to give the sample the desired roughness, flatness or thickness. Another common surface finishing process is Electropolishing which simultaneously can clean, smooth, deburr, passivate, and improves corrosion resistance. Electropolishing though highly desirable, is restricted to conductive materials which thermodinamic behavior facilitates this process. Mechanical finishing though can produce better "mirror" finishes at a lower cost and it is available to all solids.

## Technologies

### Lapping

Main article: Lapping

Lapping is the removal of large amounts of the sample material by the mechanical interaction between the sample and the abrasive surface.

### Polishing

Main article: Polishing

Here's another technology in that group.

## Figures of Merit

What these techniques should accomplish is a desired finish (roughness) and thickness.

### Roughness

When a surface's level of shininess or asperity is clearly quantified, it is called surface roughness, which plays an important role in defining the character of a surface. The roughness can control the performance of the end product in aspects such as friction, durability, operating noise, energy consumption, adhesion, wettability, airtightness, etc. In micro and -nano fabrication, having a smooth, atomically flat substrate is essential when device dimensions are comparable to the surface features.

Below are some definitions used to measure roughness:

a) Arithmetical mean deviation of the roughness profile (Ra)

This expresses the arithmetical mean of the absolute values of Z(x) in a sampling length.

● Pa Arithmetical mean deviation of the primary profile ● Wa Arithmetical mean deviation of the waviness profile

b) Root mean square deviation of the roughness profile (Rq)

## Applications

How is this technology used in nanofabrication and what types of devices/research areas is it useful in?

## See also

Other related wiki pages