Materials & surfaces

The goal of this short tutorial is to define which materials are treatable by high vacuum deposition processes. This is an important issue for those approaching deposition processes for the first time, perhaps thinking of applying them to their products.

You may have noticed that the finishing of the internal surfaces of the vacuum chambers tends to be more and more accurate as the basic vacuum you want to obtain is more severe. The reason is that the amount of water that must be managed due to the outgassing phenomenon increases with the increase in the surface roughness of the chamber.

Aluminum, although not many know it, is a metal with extraordinary properties. It does not exist in nature in the metallic state, but always in the form of compounds, the best known of which is Bauxite, in which it is contained in the form of oxides and hydroxides.

The management of the "water load" in vacuum processing always represents a problem due to the molecular composition of the water. The use of cryogenic systems can help the elimination of the water present in vacuum deposition systems.

If you have ever seen a machine for vacuum treatments, you will have noticed that the chamber in which the processing is carried out and a large part of the rest of the plant was made of stainless steel. But why, in these particular scientific and technological applications, is this material used? What are the advantages it offers (and what are the possible disadvantages)?