Overview of resistant coatings

Anti-coating is a layer of high wear resistance, corrosion resistance and high strength formed on the surface of the workpiece by different coating technologies (such as brush plating, spraying, electroplating, etc.). Resistant coatings are widely used in aviation, automotive, machinery and other industries, which can effectively extend the service life of mechanical parts and improve their working performance.

The brushes are coated with Ni-W coating

The performance of Ni-W coating on brushes

Brush Ni-W coating is a material commonly used for abrasion-resistant coatings

  • High hardness and good wear resistance - Ni-W alloy coating has high hardness and dense structure, which can effectively improve the wear resistance of the workpiece surface.

  • Low porosity – The coating has a compact structure and low porosity, which reduces oxidation and wear of the coating.

  • High stress effect - Ni-W coatings have large internal stresses and are prone to cracks if the coating thickness exceeds 0.03mm.

  • Advantages of Ni-W-D coating - Ni-W-D coating with a small amount of additives such as cobalt sulfate has less stress and can reach a thickness of 0.2mm.

Preparation process for Ni-W coating of brushes

Plating solution formulation and process conditions

  •    Plating solution A – 5g sodium tungstate + 36g citric acid + 150mL distilled water

  •    Solution B - 36g nickel sulphate + 20mL glacial acetic acid + 36g trisodium citrate + 20g anhydrous sodium sulfate

  •    Solution A is added to solution B and sodium lauryl sulfate is added as the active agent.

  •    Adjust the pH to 1.4~2.4 and keep the solution temperature at 30~50°C.

Precautions

   Temperature control - the plating solution is heated to 30~50°C before use to avoid oxidation when used at low temperatures.

   Plating solution replacement - When the plating solution is used at 80%, it needs to be replaced to prevent viscosity from increasing.

Process operations

   When the brush is plating, the negative pole of the power supply is connected to the workpiece, and the positive pole is connected to the plating pen, and the plating pen can be brushed when it is in contact with the surface of the workpiece.

The brushes are coated with Ni-P-Co

The performance of Ni-P-Co coating on brushes

Amorphous Coating – Ni-P-Co coating is an amorphous coating with high hardness and wear resistance, making it particularly suitable for use at different heat treatment temperatures.

Abrasion resistance is related to hardness – at different heat treatment temperatures, the wear resistance of a coating is directly proportional to its microhardness, the higher the microhardness, the stronger the wear resistance.

Preparation of Ni-P-Co coating for brushes

Plating solution formulation

   A low concentration of Co is added to the Co-Ni-P series alloy bath containing niobium additives.

   The desired Ni-P-Co amorphous alloy coating can be obtained by using the brush plating method at room temperature.

Flame and arc spraying with wear-resistant coatings

Low-carbon martensitic abrasion resistant primer

Coating properties

   The use of low-carbon martensitic as the wear-resistant bottom layer, the coating structure is dense and the hardness is high, which can effectively enhance the bonding strength with the matrix.

   This coating is suitable for the surface repair of moderately worn workpieces such as rolls, fan blades, and automotive crankshafts.

Coating preparation

   The coating is prepared by flame spraying or arc spraying, and the bonding strength of the coating has reached the international advanced level.

Martensitic stainless steel wear-resistant and corrosion-resistant coating

Coating properties

   Martensitic stainless steel coatings have excellent wear and corrosion resistance, especially in saltwater and SO₂ gas environments.

Coating characteristics and uses

   It is mainly used for corrosion-resistant and wear-resistant treatment on the surface of the workpiece. It is used with a low horse wear-resistant bottom layer for better results.

Composite electroplating wear-resistant coating

Definition and application of wear-resistant composite electroplating

definition

  The composite electroplating layer is a coating formed by electrochemical or chemical methods in an electrolyte solution to make metal and solid particles co-deposited on the surface of the metal, which has good wear resistance.

Classification & Application

  Ni-based wear-resistant composite plating – for parts that require high wear resistance, such as aluminum alloy parts for automotive engines.

  Fe-based, Cr-based, and Co-based composite plating layers – These coatings are typically used in high-temperature environments, such as aircraft engine components, piston rings, etc.

Ni-based wear-resistant and anti-friction composite coating

Plating solution composition and process conditions

   Ni-P-SiC Composite Coating - The plating solution contains NiSO₄·6H₂O 30g/L, NaHPO₂· H₂O 10g/L、SiC 25g/L。

   It is suitable for workpiece surfaces where friction reduction and wear resistance are required.

apply

   It is suitable for the coating treatment of automobile engine cylinders and aluminum alloy parts, and the wear amount is lower than that of the traditional chrome plating layer.

Ion plated TN and TiC coatings

Ion plating principle, characteristics and types

principle

   Ion plating is a physical vapor deposition (PVD) method in which high-energy ions bombard the surface of a workpiece, causing the coating to be deposited to form a high-strength, dense coating.

peculiarity

   The coating has strong adhesion, smooth and uniform surface, and good wear resistance.

   It can avoid the pollution problems caused by the traditional electroplating process and is environmentally friendly.

Preparation of TiN coatings

Plating solution pretreatment

  Clean the plated parts, eliminate static electricity, apply primer, and improve the adhesion of the coating.

Process conditions

   Ion plating deposition is carried out in a vacuum environment and a TiN coating is formed by ion bombardment.

summary

Resistant coating technology plays a vital role in modern manufacturing, especially in demanding wear-resistant and corrosion-resistant applications. With the continuous development of coating materials and processes, the performance of coatings is becoming more and more powerful, which can effectively improve the service life and work efficiency of mechanical parts. Through brush plating, spraying, composite electroplating, ion plating and other technologies, coating can meet the needs of various complex environments, and has become one of the indispensable technologies in the modern industrial field.


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