1. The production process is different:
Chrome electroplating is a traditional surface electroplating technology that has been used for more than 70 years. The commonly used chromic acid plating solution for chrome plating, compared with other single metal plating solutions, although the composition of the chrome plating solution is simple, the chrome plating process is quite complicated. The main component of the chrome plating solution is not a metal chromium salt, but the oxo acid of chromium – chromic acid, which belongs to a strong acid plating solution. The disadvantage is that the electroplating process of chromium will cause environmental pollution problems. In fact, it is not chrome itself that causes environmental problems, but the chrome plating process. The main problem is the chromic acid solution used in the chrome plating process, which produces acid mist and wastewater. Therefore, the restrictions on the chrome plating process in various countries will become more and more strict.
Chrome coating is to use thermal spraying technology to send a certain coating material (powder or wire) into a certain heat source (arc, combustion flame, plasma) to melt, and use high-speed airflow to spray it onto the surface of the base material to form a coating layer process.
2. Different applications:
Chromium electroplating is generally applied to the surface of the product position of the mold. After electroplating chromium treatment, the surface of the mold and workpiece will be smooth, easy to demould, and will not rust; it is also applied to the surface of household appliances, bathroom products, auto parts, etc. decorate.
The application range of sprayed chrome is very wide, involving various sectors of the national economy and various fields including cutting-edge technology.
3. Extended information:
Chromium is a kind of silver-white metal with microstrip blue. Chromium metal is easily passivated in the air, and a very thin passivation film is formed on the surface, thus showing the properties of precious metals. The chromium plating layer has high hardness, and its hardness can vary within a wide range of 40-120HV according to the composition of the plating solution and process conditions. The chrome plating layer has good heat resistance. When heated below 50 °C, its gloss and hardness have no obvious change. When the temperature is higher than 50 °C, it begins to oxidize and discolor, and when it is higher than 70 °C, the hardness begins to decrease. The friction coefficient of the chrome-plated layer is small.
Chrome plating treatment:
1. Pretreatment
In general, steel parts are plated with black chrome, and most of them use copper or nickel as the bottom coating, while high-end products often use copper, nickel milky white chrome, and black chrome combined coatings as protective decorative coatings. The copper alloy parts can be directly plated with black chrome after pretreatments such as degreasing and pickling, while the high-end products are plated with nickel as the bottom coating, and then plated with black chrome, which has a better protective decoration effect.
2. Post-processing
After the parts of electroplated black chrome products are cleaned and dried, if they are sealed with hot oil, their protective and decorative effect will be further improved, and organic transparent coatings are also sprayed on the surface to greatly improve the protective and decorative effect.