Mechanical Plating

Overview of Mechanical Plating

Mechanical plating is a non-electrolytic process used to coat metal parts with a thin layer of another metal, most often zinc. Unlike electroplating, mechanical plating does not require electrical current. Instead, it relies on mechanical energy, typically through tumbling the parts with metal powder, glass beads, and chemical promoters in a rotating drum. This process is particularly suited for small, bulk parts such as fasteners, washers, and stampings.

Process Characteristics

• Non-electrolytic: No electrical power is needed, making it suitable for coating complex shapes and avoiding issues like hydrogen embrittlement.
• Bulk Processing: Mechanical plating is efficient for high-volume production of small parts.
• Common Coatings: Zinc is the most frequently applied metal, but other metals such as tin and cadmium can also be used.

Applications and Advantages

Mechanical plating is widely used in industries requiring corrosion protection for small steel components. The process produces a uniform coating and is often preferred when hydrogen embrittlement must be avoided, such as in high-strength fasteners. Mechanical plating can also achieve good adhesion and coverage on parts with complex geometries.

Comparison with Electroplating

While both mechanical plating and electroplating are used to deposit protective metal coatings, mechanical plating offers advantages for certain part types and applications. It does not introduce hydrogen into the substrate, reducing the risk of embrittlement. Mechanical plating is also more suitable for processing large quantities of small parts simultaneously.

Considerations

• Best suited for small, bulk parts
• Typically used for corrosion resistance
• Not ideal for parts requiring very thick or decorative coatings

Mechanical plating is a practical solution for manufacturers seeking efficient, non-electrolytic metal finishing for small components requiring corrosion protection.