What is the difference between blackening surface treatment and electroplating in Dalian?

Dalian blackening surface treatment and electroplating are two common metal surface treatment processes, which have significant differences in principles, applications, and performance characteristics. The following will analyze in detail the differences between these two processes from multiple perspectives.

1、 Principle and Process

1. Blackened surface treatment

Blackening treatment is a chemical surface treatment process that mainly generates a dense oxide film on the metal surface through chemical reactions. Common blackening methods include alkaline blackening, room temperature blackening, and high temperature blackening. The basic principle is to place a metal (usually steel) in a specific chemical solution and generate a black or blue black oxide film on the surface through oxidation reaction (mainly iron tetroxide, Fe ∝ O ₄). Blackening treatment does not require electricity and belongs to the chemical conversion coating process.

The process flow of blackening treatment generally includes the following steps:

Cleaning: Remove oil stains and impurities from metal surfaces.

Acid washing: Removing oxide scale and rust from metal surfaces.

Blackening treatment: Immerse the metal in black liquor for chemical reaction.

Post treatment: including water washing, drying, oiling and other steps to improve the corrosion resistance and appearance quality of the surface facial mask layer.

2. Electroplating

Electroplating is an electrochemical surface treatment process that deposits a layer of metal or alloy coating on a metal surface through electrolysis. The basic principle of electroplating is to use the workpiece as the cathode and the plated metal as the anode, place them in an electrolyte containing metal ions, and apply an external current to reduce and deposit the metal ions on the surface of the workpiece. The electroplating process can coat various metals, such as zinc, nickel, chromium, copper, gold, silver, etc.

The electroplating process generally includes the following steps:

Cleaning: Remove oil stains and impurities from metal surfaces.

Acid washing or activation: Remove the oxide scale on the metal surface and activate the surface to improve the adhesion of the coating.

Electroplating: Electroplating is carried out in an electrolytic cell by controlling parameters such as current density, temperature, and time to obtain the desired coating.

Post treatment: including steps such as water washing, drying, passivation, etc., to improve the corrosion resistance and appearance quality of the coating.

2、 Application Fields

1. Blackened surface treatment

Blackening treatment is mainly used for surface protection and decoration of steel products, and common application areas include:

Blackening treatment can improve the wear resistance and corrosion resistance of mechanical parts such as gears, bearings, fasteners, etc.

Tools such as wrenches, pliers, etc. Blackening treatment can improve the appearance of tools and extend their service life.

Blackening treatment can enhance the corrosion resistance of automotive components such as brake discs and steering knuckles.

Firearms and knives: Blackening treatment is commonly used for surface treatment of firearms and knives to improve their wear resistance and concealment.

2. Electroplating

The application scope of electroplating is very wide, covering almost all industrial fields. Common applications include:

Anti corrosion: such as galvanizing, nickel plating, etc., used to improve the corrosion resistance of metal products.

Decoration: such as chrome plating, gold plating, silver plating, etc., used to improve the appearance quality and decorative effect of products.

Functional coating: such as hard chrome plating, copper plating, etc., used to improve the wear resistance, conductivity, or thermal conductivity of parts.

Electronic industry: Copper plating, gold plating, etc. on printed circuit boards (PCBs) are used to improve the conductivity and reliability of circuits.

3、 Performance characteristics

1. Blackened surface treatment

Corrosion resistance: The oxide film generated by blackening treatment has a certain degree of corrosion resistance, but it is usually not as good as electroplating, especially in harsh environments.

Wear resistance: Blackening treatment can improve the wear resistance of metal surfaces, but the wear resistance is relatively low and suitable for light load conditions.

Appearance: The surface after blackening treatment appears black or blue black, with a certain decorative effect, but the color is single.

Cost: Blackening treatment has a lower cost, simple equipment, and is suitable for large-scale production.

Environmental friendliness: The chemicals used in the blackening process may have a certain impact on the environment and require proper treatment of wastewater.

2. Electroplating

Corrosion resistance: Electroplated coatings usually have good corrosion resistance, especially galvanized and nickel plated coatings, which can effectively prevent corrosion of metal substrates.

Wear resistance: Some electroplating layers (such as hard chromium plating) have high wear resistance and are suitable for high load conditions.

Appearance: The electroplated layer can present various colors and luster, such as bright silver plated with chrome, golden plated with gold, etc., with a good decorative effect.

Cost: The cost of electroplating is relatively high, especially for precious metal electroplating (such as gold plating and silver plating), and the equipment is complex with high process control requirements.

Environmental friendliness: The electrolyte and additives used in the electroplating process may contain harmful substances, and the requirements for wastewater treatment are high, resulting in significant environmental pressure.

4、 Comparison of advantages and disadvantages

1. Blackened surface treatment

advantage:

Low cost and simple process.

Suitable for large-scale production.

Has certain corrosion resistance and wear resistance.

The appearance effect is good, especially suitable for black or blue black decoration.

Disadvantages:

The corrosion resistance and wear resistance are relatively low.

Single color, limited decorative effect.

Poor environmental friendliness and high requirements for wastewater treatment.

2. Electroplating

advantage:

Good corrosion resistance and wear resistance, especially suitable for harsh environments.

There are various decorative effects that can present a variety of colors and gloss.

Functional coatings can meet special performance requirements such as conductivity, thermal conductivity, etc.

Disadvantages:

The cost is relatively high, especially for precious metal electroplating.

The process is complex and the equipment requirements are high.

The pressure of environmental protection is high, and the requirements for wastewater treatment are strict.

Blackening surface treatment and electroplating are two different metal surface treatment processes, each with its unique advantages and application areas. Blackening treatment has low cost and simple process, suitable for occasions with low requirements for corrosion resistance and wear resistance, especially for products with black or blue black decorative effects. Electroplating has better corrosion resistance, wear resistance, and decorative effect, and is suitable for occasions with high performance requirements. However, the cost is high, the process is complex, and the environmental pressure is high.

In practical applications, the choice of process should be comprehensively considered based on the performance requirements, cost budget, and environmental protection requirements of the specific product. For example, for general mechanical parts, blackening treatment may be sufficient; For high-end decorations or parts under high load conditions, electroplating is a better choice.