Diffusion

Diffusion describes a physical process in which particles (atoms, molecules or electrons) move from areas of higher concentration to areas of lower concentration. The end of a diffusion process is homogeneity.

Diffusion processes occur much faster at high temperatures than at low temperatures.

Diffusion processes occur automatically in gases and liquids. The greater the differences in concentration, the faster they take place.

With highly viscous substances and solids, concentration equalisation is much faster with the aid of a mixing element.

Even inhomogeneous solids can equalise concentration differences through diffusion processes without a mechanical mixing process taking place. However, this takes a very long time. This type of homogenisation is not used in practice.

Diffusion plays a subordinate role in the powder mixing process used in industrial mixing technology. However, if bulk materials are stored for a very long time, diffusion always occurs, i.e. differences in concentration are equalised. This can improve or worsen the quality of powder mixtures.

amixon® mixers are used in powder metallurgical processes. Solid diffusion occurs after sintering, particularly during mechanical alloying.