Principles of Chrome Plating, Chromium Plating Process Need to Know
The principle of chromium plating - Chromium plating to minimize friction, improve product durability is a method of coating a layer of chromium on the surface of metal products. This coating can be used for decorative objects, while increasing absolute abrasion resistance, smoothness and increased surface hardness.
Features and applications of the chrome plating layer are silver bright, light blue, and durable. Chromium is chemically stable, shiny surface reflects light well, abrasion resistance should be widely applied to create an additional layer of protection in plating industry for automobile, bicycle and motorbike industry. , manufacturing machines, appliances and household appliances.
The principle of chromium plating is divided into 2 main types
- The chromium plating method uses chromium 6+ plating, also known as valence 6, is the chromium plating method that uses the trioxide CrO3 solution as a key component, this method is mainly used for decorative plating and hard plating. .
- The chromium plating method using chromium plating 3+ is an alternative to chromium 6+ plating solution in some applications to improve thickness (for example, decorative plating).
The chrome plating process 6+ and 3+ is similar to other electroplating processes:
- Pickling oil
- Activation
- Chrome electroplating
- Wash
Standard solutions in chromium plating (chromium 6+ and chromium 3+)
For chromium plating 6+
According to the standard of solution, the chromium 6+ plating principle is a mixture of solutions: trioxide -CrO 3 and sulfuric-sulfate acid, SO 4, chromium 6+ plating containing highly acidic solution (pH 0).
For chromium plating 3+
Different from the tank containing solution of chromium 6+, chromium 3+ plating containing chloride or sulfate solution using graphite or can use composite anodes, adding some other additives to support the purpose to prevent Oxidation of chromium 3+ to the anode, which maintains an electrode potential that can prevent oxidation.
Principle of Hard Chrome plating
Hard chrome plating, also known as industrial chromium plating, is mainly used to minimize friction, improve product durability through abrasion and friction resistance, wear and tear restoration, expand resistance to high chemical corrosion in the harshest corrosive environments.
The chromium coating is quite hard, with a hardness ranging from 65 HRC to 69 HRC - in addition to the hardness of metal products. Hard chromium plating is thicker than decorative chromium plating, with the standard thickness in applications ranging from 200 - 600 mm, can be thick plated for parts that require high abrasion resistance, friction resistance, in this case 1 mm is equivalent to 1,000 micrometres or possibly thicker still gives good results.
For products that require thick plating, chromium plating will increase the roughness of the roughness when the product is rough, so in the hard chrome plating process, plating will be thicker than the actual requirements, grinding again. to be able to achieve the right size and aesthetics. This causes a relatively large waste and prolongs processing time.
This chromium plating technology is used in automotive and other light decorative products, as well as steel that has undergone plating to withstand the wide range of temperature and weather changes that a The car depends on the exterior beauty.
Chrome plated classification
Chromium plating is divided into several types: decorative chromium, hard chrome, alloy chrome, corrosion resistant chromium. In fact, chrome plating in Vietnam is divided into two types: decorative coatings that improve product features for eye-catching blue light and technical coating.
The choice of thickness and hardness in the chromium plating process is a technical decision, improving the best efficiency of the product we need to gain the knowledge needed to choose it, otherwise it will bring the price. reverse treatment.
If you still have questions or want to learn more about the chromium plating principle, please contact Viet Nhat to get the most enthusiastic advice and answer the best questions.
