How to Distinguish Between Hot Plating and Cold Plating
Author:Robby
Hot plating, is a metal workpiece after cleaning, preheating, melting, holding, cooling and other steps, the workpiece surface to form a layer of metal plating process method.
The principle of hot-dip plating is to utilize the electrochemical reaction between metals to make the plated metal form a dense alloy layer on the surface of the workpiece, so as to enhance the corrosion resistance of the workpiece and improve the smoothness of the workpiece.
Hot-dip galvanizing is widely used in the anti-corrosion treatment of various metal products, such as steel, aluminum alloys, copper alloys and so on.
Take “hot-dip galvanizing” as an example: there is a potential difference between the iron atoms on the surface of the workpiece and the zinc atoms in the plating solution, which causes the iron atoms to become the anode and the zinc atoms to become the cathode, thus forming a primary battery. Using the process of electrochemical reaction between zinc and iron, zinc atoms will be deposited from the plating solution onto the surface of the workpiece, forming a dense layer of zinc-iron alloy, thus playing a role in corrosion prevention. Hot-dip galvanizing technology can be applied to the anti-corrosion treatment of steel products such as bridges, buildings, pipelines, bolts and nuts, and large steel components, keeping them rust-free for decades.
Cold plating refers to the treatment technology of depositing metals or alloys on the surface of the substrate by electrolysis or other chemical methods, such as electroplating, chemical plating, spraying, etc., at room temperature.
Cold plating will form a layer of dense and uniform plating film, this plating can play a protective, decorative, corrosion resistance and so on.
Cold plating is easy to operate, environmentally friendly, and allows precise control of the thickness and structure of the coating, making it suitable for small, fine, high-precision, and high-value-added product surface treatment.
Hot plating and cold plating are two different metal surface treatment methods, which can be distinguished from the following aspects:
Thickness:
The plating layer of hot plating is thicker, generally 30-60μm, while the plating layer of cold plating is thinner, generally 10-20μm.
Appearance:
The surface of the plated layer of hot plating is smooth, dense, consistent color, no bubbles, cracks, peeling and other phenomena. While the surface of cold plated plating may have bubbles, cracks, peeling, etc., and the color may not be consistent.
Abrasion resistance:
The plating of hot plating has better abrasion resistance, corrosion resistance and impact resistance, while the plating of cold plating is relatively weak.
Environmental friendliness:
Hot plating produces a large amount of waste gas and slag. Compared with hot plating, the temperature of cold plating is lower, usually controlled at or near room temperature, which reduces the heat loss and energy consumption of the reaction, and the process of cold plating is simple and has little effect on the physical properties of the substrate.