Mechanical Plating

Mechanical Plating: Advanced Surface Treatment for Corrosion Protection

The core principle of mechanical plating is cold bonding, in which metal particles are applied to a substrate by mechanical agitation. The substrate and metal particles are placed in a rotating drum along with impact media (e.g., glass beads) that continuously strike the surface. This frictional force causes the metal particles to physically penetrate the substrate, creating a well bonded metal layer. The process does not require electric current or high temperatures, making it ideal for parts that cannot withstand heat. The sequence of the process involves cleaning the parts, placing them in the rotating drum with metal powder and impact media, and controlled application of the metal coating by agitation.

Types of Treatments/Variants

Mechanical plating is available in several forms, each tailored to specific performance requirements. The most common types are:

• Zinc Mechanical Plating: Provides excellent corrosion protection and is often used for industrial fasteners. Zinc coatings typically range from 5 to 25 microns thick, providing uniform coverage without excessive material deposits.
• Tin Mechanical Plating: Ideal for applications where enhanced electrical conductivity along with corrosion protection is required. It is often used for electrical connectors and sensitive small parts.
• Combination coatings: In some cases, zinc is followed by a chromate conversion coating to further improve corrosion resistance and aesthetics, providing a wider range of protective capabilities.

Each variant has specific properties such as coating thickness, hardness and surface finish. Zinc is more cost-effective for general corrosion protection, while tin is preferred for more specialized, electronics-oriented applications.

Material compatibility

Mechanical plating is most effective on ferrous metals such as steel, iron and certain alloys, making it a popular choice for fasteners and structural components. Pretreatment steps such as cleaning and degreasing are crucial to ensure proper adhesion, as surface contaminants can affect the quality of the coating. Although mechanical plating is compatible with a variety of materials, certain non-metallic substrates such as plastics or composites may require alternative treatments due to the physical nature of the process. Our expertise in working with different materials allows us to provide optimal preparation methods, ensuring excellent adhesion even to substrates with challenging surface textures.

Performance Benefits

The biggest advantage of mechanical plating is its excellent corrosion protection. Zinc-plated fasteners, for example, can withstand long-term exposure to corrosive environments and meet or exceed industry standards such as ASTM B695 for corrosion resistance. The thin, uniform coating ensures that even complex geometries are completely covered without the risk of bridging or uneven thickness, which is especially important for threaded parts. In addition, mechanical plating offers better adhesion compared to other methods such as hot dip galvanizing, with a more controlled coating thickness. This makes it perfect for parts that require precise fit. Quantitatively, zinc mechanical coatings can provide more than 500 hours of protection in salt spray tests, ensuring long life in aggressive environments.

Applications & Relevance to Industry

Mechanical plating is widely used in industries such as construction, automotive and electronics. In construction, zinc-coated fasteners are essential for steel structures, where corrosion protection is critical for frame durability. The automotive industry relies on mechanical plating for components such as screws and bolts, particularly in areas exposed to moisture and salt. In electronics, tin plating is preferred for connectors and small parts because of its ability to prevent oxidation and ensure electrical conductivity. Successful examples include projects where mechanical plating has extended the life of fasteners in outdoor applications such as bridges and telecommunications towers, significantly reducing maintenance costs and increasing reliability.

Customization & Process Optimization

A key advantage of mechanical plating is its customization potential. We offer customized solutions that allow customers to specify coating thickness, surface finish and post-treatment options, such as chromating for improved corrosion resistance. Our process control allows us to make adjustments in agitation rate, media type and plating material to meet the unique requirements of each application. For example, we can refine the zinc plating process to create a thicker coating for parts exposed to more corrosive environments, or customize the finish for aesthetic purposes, such as a matte or polished appearance, depending on customer requirements.