The anti-corrosion mechanism of Dacromet surface coating equipment is a three-dimensional protective film integrating physical shielding, cathodic protection, passivation and electrochemical protection. It can provide very good anti-corrosion protection for precious gold.
(1) Physical shielding
Due to the overlapping arrangement of the flaky metal powder in the coating, fillers, etc. are filled in the microscopic voids of the zinc-aluminum powder to reduce the voids of the coating, thereby forming a very effective barrier layer. The path that causes the aggressive ions to reach the matrix is ​​tortuous and difficult, and acts as a shield for physical protection.
(2) Electrochemical action
Since the activity of zinc-aluminum is higher than that of iron, after the zinc-aluminum coating and the steel substrate form a micro-corrosion primary battery, the scaly zinc-aluminum powder can be corroded first as an anode, thereby providing cathodic protection for the steel substrate.
(3) passivation
Since aluminum is oxidizable in the atmosphere, a dense oxide film will be formed on the surface of Xinxiang Dacromet, which will better prevent the penetration of corrosive media. In addition, the passivation agent added to the coating can slow down Corrosion of metals such as zinc and aluminum, thereby reducing the corrosion rate of the substrate.