Electroplating related effects

The technology of using electrolytic cell principle to deposit metal coating with good adhesion but different performance and substrate material on mechanical products. Electroplated coatings are more uniform than hot-dip coatings and are generally thinner, ranging from a few micrometers to tens of micrometers. Through electroplating, decorative protective and various functional surface layers can be obtained on mechanical products, and workpieces with wear and processing errors can also be repaired.
In addition, there are different functions depending on various electroplating needs. For example:
1. Copper plating: used as a base to enhance the adhesion and corrosion resistance of the electroplating layer. (Copper is prone to oxidation, and after oxidation, copper green no longer conducts electricity, so copper plated products must be protected with copper)
2. Nickel plating: used as a base or for appearance, to enhance corrosion resistance and wear resistance (among which chemical nickel has a higher wear resistance than chromium plating in modern processes). (Note that many electronic products, such as DIN heads and N heads, no longer use nickel as a substrate, mainly due to the magnetic properties of nickel, which can affect passive intermodulation in electrical performance)
3. Plating: Improves conductive contact impedance and enhances signal transmission. (Gold is the most stable and expensive.)
4. Palladium nickel plating: improves conductive contact impedance, enhances signal transmission, and has higher wear resistance than gold.
5. Tin plated lead: improves soldering ability and is quickly replaced by other substitutes (due to the presence of lead, it is now mostly replaced with bright tin and fog tin).
6. Silver plating: improves conductive contact impedance and enhances signal transmission. (Silver has the best performance, is easy to oxidize, and also conducts electricity after oxidation)
Electroplating is a method of laying a layer of metal on a conductive body using the principle of electrolysis.
In addition to conductive materials, electroplating can also be used on specially treated plastics.
The process of electroplating is basically as follows:
Plating metal on anode
The substance to be plated is on the cathode
The anode and cathode are connected by an electrolyte solution composed of positive ions of the metal plated on them
After applying a direct current power supply, the metal at the anode will oxidize (losing electrons), and the positive ions in the solution will be reduced at the cathode (obtaining electrons) to form atoms and accumulate on the surface of the cathode.
The aesthetics of the electroplated object after electroplating are related to the size of the current. The smaller the current, the more beautiful the electroplated object will be; On the contrary, some uneven shapes will appear.
The main uses of electroplating include preventing metal oxidation (such as rust) and for decoration. The outer layer of many coins is also electroplated.
Wastewater generated by electroplating (such as ineffective electrolytes) is an important source of water pollution. Electroplating technology has been widely used in the process of semiconductor and microelectronic component lead frames.
VCP: Vertical continuous electroplating, a new type of machine used for circuit boards, with better quality than traditional suspended electroplating.
Local silver plating
Process flow of aluminum electroplating solution formula:
High temperature weak alkali etching → cleaning → acid washing → cleaning → zinc immersion → cleaning → secondary zinc immersion → cleaning → pre copper plating → cleaning → pre silver plating → cyanide bright silver plating → recycling washing → cleaning → silver protection → cleaning → drying.
From the perspective of process flow, the selected protective material must be resistant to high temperature (around 80 ℃), alkali, and acid. Secondly, the protective material can be easily peeled off after silver plating.
The commercially available protective materials include peelable rubber, peelable paint, general adhesive tape, and tape. Test the acid resistance, alkali corrosion resistance, high temperature resistance (maximum temperature of alkali corrosion solution around 80 ℃), and peel resistance of these protective materials separately.