Probably, every person wants to know, why over time the copper turns green and becomes bloomed. This is easy to explain: that film is called patina.
It appears due to the oxidation of the surface. The color range of patina varies from bright green to azure blue. So each alloy has its own shade of plaque. Any copper and zinc alloys are called brass. The color of the patina on them has a bluish-green hue.
Copper alloys with other metals are called bronzes. They have a bright green coating, and depending on the impurity, it will change the saturation. Patina and its types Patina is a protective film that covers copper when oxidized in air. It is needed to protect products from further destruction.
Patina can be divided into several categories:
• noble;
• wild.
Noble patina on copper objects is black. It protects it from further oxidation and destruction of the surface. The "wild" patina is green. It appears on products in a humid environment. Why it is not appreciated? Because, this kind of its appearance is a consequence of improper maintenance of the metal, as a result of which there are depressions that are corrosive.
It manifests itself in the formation on the metal of caverns, that is, numerous depressions. Wild patina can be removed only by mechanical cleaning. This can spoil the appearance, since the green coating will be removed along with its top layer of metal.
