What plating options are available for corrosion protection?

What Plating Options Are Available for Corrosion Protection?

Purpose of Plating in Metal Components

Plating is a critical surface treatment used to improve the corrosion resistance, durability, and appearance of metal parts. For die cast components made from zinc or aluminum alloys, plating extends service life, enhances conductivity (for electrical applications), and prepares the surface for harsh environments such as automotive, marine, and industrial settings.

Common Plating Options for Corrosion Resistance

Nickel Plating

• Electroless Nickel (EN): Provides uniform thickness, excellent corrosion resistance, and moderate hardness. Ideal for complex shapes and tight tolerance parts.

• Electrolytic Nickel: Common for decorative and functional applications, often layered over copper for improved adhesion.

Best used for: Electrical housings, mechanical interfaces, decorative trim components

Chrome Plating

• Hexavalent Chrome: Traditional bright chrome with excellent wear and corrosion resistance but being phased out due to environmental concerns.

• Trivalent Chrome: Modern alternative with lower toxicity, suitable for both functional and aesthetic purposes.

Best used for: Automotive handles, decorative bezels, high-wear exterior parts

Zinc Plating

• Provides sacrificial protection by corroding before the base metal. Often used over steel parts.

• Can be enhanced with chromate conversion coatings for added corrosion protection and passivation.

Best used for: Fasteners, brackets, structural components in automotive and machinery

Tin Plating

• Offers good corrosion resistance and solderability.

• Preferred in electrical applications for connectors and terminals.

Best used for: Electrical connectors, terminals, busbars

Copper Plating

• Acts as a base layer for other finishes like nickel or chrome.

• Improves adhesion and conductivity but is not corrosion-resistant on its own.

Best used for: Multilayer plating systems in EMI/RFI shielding or aesthetic parts

Plating Over Zamak and Aluminum Die Castings

Zamak components such as those made from Zamak 3 or Zamak 5 are excellent for plating after surface preparation:

• Pre-treatment includes polishing, tumbling, and copper strike plating for adhesion.

• Multi-layer systems like Cu-Ni-Cr are common for decorative automotive parts.

Aluminum die castings require pre-plate treatments such as zincate conversion before plating to ensure good adhesion.

Neway’s Surface Finishing and Plating Capabilities

Neway offers complete post-processing for corrosion protection, including:

• Pre-plate CNC machining for sealing surfaces and dimensional accuracy

• Electroplating coordination with multi-layer systems (Cu-Ni-Cr, Ni-P)

• Surface inspection and corrosion testing to meet automotive and industrial standards