1、 Pre plating pretreatment

The purpose of pre-treatment before plating is to obtain a clean and fresh metal surface, and to prepare for the final high-quality coating, which involves degreasing, rust removal, dust removal, and other work.

The steps are as follows:

Step 1: Make the surface roughness meet certain requirements, which can be achieved through surface polishing, polishing and other process methods;

Step 2: Degreasing and degreasing can be achieved through solvent dissolution, chemical, electrochemical, and other methods;

Step 3: Rust removal, which can be achieved through mechanical, acid pickling, and electrochemical methods;

Step 4: Activation treatment, usually carried out before plating by etching in weak acid for a certain period of time.

2、 Post plating treatment

1. Passivation treatment

The so-called passivation treatment refers to a surface treatment method that involves chemical treatment in a certain solution to form a solid, dense, and stable thin film on the coating. Passivation greatly improves the corrosion resistance of the coating and can increase its surface gloss and pollution resistance. This method has a wide range of uses, and can be passivated after plating with Zn, Cu, and Ag.

2. Dehydrogenation treatment

Some metals, such as zinc, during the electrodeposition process, in addition to depositing themselves, also precipitate a portion of hydrogen, which seeps into the coating, causing brittleness or even fracture of the plated part, known as hydrogen embrittlement. In order to eliminate hydrogen embrittlement, it is often necessary to heat treat the plated parts at a certain temperature for several hours after electroplating, which is called dehydrogenation treatment.