Definition - What does Precipitation mean?
Precipitation refers to the physical process of solid or liquid particulate dispersion from a fluid. Precipitation is often seen in metal protection mechanisms against corrosion such as the setting of pigments by the removal of salts and water from the pigment mixture.
Corrosionpedia explains Precipitation
Precipitation is the creation of a solid in a solution during a chemical reaction or by diffusion. Liquid solution reactions form a solid that is called the precipitate. The chemical that propels the solid formation is referred to as the precipitant. Typically, precipitate remains suspended in solution due to inadequate gravitational forces acting on it.
The metallurgy process of alloy strengthening uses the process of precipitation from solid solutions. The process is also known as solid solution strengthening and may be used in purifying products or removing contamination. The presence of contaminants may otherwise lead to increased corrosion occurrence in metal equipment applications such as heat exchanges or boilers. The presence of such particulate matter adheres to a metal surface, causing pitting and crevice corrosion.
Precipitation can also cause atmospheric corrosion and hardening of metal alloys. Atmospheric corrosion is the deterioration and destruction of a material and its vital properties due to electrochemical as well as the other reactions of its surface with the constituents of the atmosphere surrounding the material.