The role of electroplating additives may not be well understood by many people. According to their functions, they can be divided into complexing agents, brighteners, surfactants, leveling agents, stress relief agents, impurity removal agents, and wetting agents, among which brighteners and surfactants are important. It refers to the collective term for various chemical substances that need to be added to the plating solution in order to improve the quality of the coating in the electroplating process.
The role of electroplating additives in galvanized products
We often use colored zinc water, blue zinc water, black passivating agents, etc. Using colored zinc water can increase the glossiness of the galvanized layer, increase the corrosion resistance of the product, and make it less prone to discoloration and scratching. Moreover, the color of the galvanized parts also feels more vibrant. The addition of blue zinc water also makes the brightness of electroplated products more uniform, and increases the blue brightness of electroplated parts, improving the product's grade. Of course, it also plays a certain role in increasing the durability and corrosion resistance of electroplated films, and also increases the product's ability to resist collisions.
Serve as a purifying agent
Electroplating additives prevent the product from reacting with oxygen in the air, thus preventing oxidation. Black passivating agents form a black protective film on the surface of the product, giving it a more noble and elegant appearance.
Of course, these electroplating additives also have high requirements for operation. The concentration, temperature, and pH of the solution will affect the electroplating effect, and frequent adjustments and strict adherence to operating procedures are needed during the operation process.
The electroplating additive analyzer can accurately adjust the concentration of additives, ensuring the continuity and interference free operation. Especially the accuracy of the analysis results has made this method accepted by the electroplating industry. Other methods, such as the classic Hull cell method, can only provide an assessment of coating quality and cannot determine additive concentration.
The mechanism of action of the electroplating additive tester:
The process of metal electrodeposition is carried out in stages: firstly, the electroactive material particles migrate to the outer Helmholtz layer near the cathode for electro adsorption, and then the cathode charge is transferred to the adsorbed portion of the electrode to form adsorbed atoms, which then migrate on the electrode surface until they merge into the lattice. The above processes all generate certain overpotentials (namely migration overpotential
Activation overpotential and electrocrystallization overpotential). Only under a certain overpotential can the electroplating process of metals have a sufficiently high grain nucleation rate, moderate charge migration rate, and sufficiently high crystallization overpotential, thereby ensuring that the coating is smooth, dense, glossy, and firmly bonded to the substrate material. Appropriate electroplating additives can increase the overpotential of metal electrodeposition, providing strong guarantees for the quality of the coating.