In fact, in the precision etching line processing industry, many customers are not very familiar with passivation. Here is a detailed analysis of the passivation process.

The passivation of the metal surface is a method in which the metal surface is exposed to the air or chemical or electrochemical methods to transform the active state of the metal surface into a passive state that is not easily oxidized, thereby delaying the corrosion or further oxidation of the metal. The former can be called natural passivation, and the latter can be called artificial passivation. The passivation treatment of the metal workpiece before etching the anti-corrosion layer has two purposes: ① to prevent the metal surface from rusting; ② the adhesion of the anti-corrosion layer can be improved through the passivation film.

In the common metal etching, if the aluminum workpiece does not need to be anodized before the anti-corrosion treatment, then the surface of the workpiece should be chemically passivated after the cleaning treatment, otherwise the aluminum surface will easily produce water during the drying or transportation process. Imprinting affects the bonding force of the anti-corrosion layer and the aluminum substrate. For the surface of the aluminum workpiece, if there is a special need, chemical oxidation can be used to increase the thickness of the film. Experiments have shown that the aluminum surface with an oxide film is easier to bond with the anti-corrosion layer reliably.

If the copper and alloy workpieces are etched and processed by pickling and water washing, if they are not quickly dried, it is easy to generate patina on the copper surface and affect the anti-corrosion effect. At this time, passivation can also be used to prevent patina.

After the stainless steel parts are corroded, if the salt spray time needs to be increased, purification methods should also be used to increase the salt spray time at this time.

Generally speaking, passivation can be used for pretreatment of metals that are prone to rust in a water vapor environment. The passivation treatment should pay attention to the passivation treatment of the metal surface layer instead of the chemical oxidation treatment. The passivation film produced by the special passivation is a very dense and good bonding protective layer, which is different from the metal material. Passivation film generated in the natural environment.

This process is not necessary for every metal. It should be determined according to the nature of the metal material and the requirements for the product. At the same time, before deciding whether to use passivation treatment, process tests should be carried out to obtain reliable Decide whether to choose after the experimental data.