Learn about electroplating for sheet metal parts. Discover plating types, process steps, thickness standards, and applications for corrosion and wear resistance.
Introduction
Electroplating deposits a thin metal layer on a substrate through electrolysis. At Fulei Metal, we provide electroplating services for components requiring specific surface properties.
What is Electroplating?
The part is immersed in an electrolyte solution containing metal ions. An electric current causes metal ions to deposit on the part (cathode). The anode supplies metal ions. The result is a thin, uniform metal coating.
Common Plating Types
Zinc Plating
Most common for steel parts. Corrosion protection. Can be clear (blue), yellow, or black passivated. Thickness: 5-15 microns. Cost-effective. Used for fasteners, brackets, and general hardware.
Nickel Plating
Excellent corrosion resistance. Attractive appearance. Can be decorative or functional. Thickness: 5-25 microns. Used for decorative parts, food equipment, and wear surfaces.
Chrome Plating
Hard chrome for wear resistance. Decorative chrome for appearance. Thickness: 0.5-25 microns (decorative), 25-250 microns (hard chrome). Used for hydraulic cylinders, molds, and decorative trim.
Copper Plating
Often used as undercoat for other plating. Good electrical conductivity. Thickness: 2-10 microns. Used for electronics and as a base for nickel-chrome.
Tin Plating
Food-safe and non-toxic. Good solderability. Corrosion resistant. Thickness: 2-10 microns. Used for food equipment, electrical contacts, and soldering surfaces.
Process Steps
Surface Preparation
Degreasing: remove oils and grease. Electrocleaning: remove fine contamination. Acid activation: remove oxide layer. Surface must be perfectly clean for good adhesion.
Plating
Immersion in plating bath. Electric current applied. Duration determines thickness. Temperature and chemistry controlled. Agitation for uniform deposition.
Post-Treatment
Rinsing between steps. Passivation (zinc). Neutralization. Drying. Optional topcoat or sealer.
Design Considerations
Recessed Areas
Recesses may not plate adequately. Electric field is weaker in recesses. Consider design modifications. Use barrel plating for small parts.
Sharp Edges
Plating builds up on edges and points. May be thinner on flat surfaces. Round edges for more uniform coating.
Blind Holes
Solution may not circulate properly. May have thin or no plating. Provide drain holes if possible.
Material Compatibility
Some materials are difficult to plate. Aluminum requires special pre-treatment. Stainless steel requires activation. Cast iron may have porosity issues.
Thickness Standards
ISO 2081: zinc plating thickness. ISO 1456: nickel-chromium plating. ASTM B633: zinc plating. Typical: 5-8 microns for indoor, 12-25 microns for outdoor.
Quality Testing
Thickness: X-ray fluorescence, magnetic gauge. Adhesion: bend test, tape test. Salt spray: corrosion resistance. Appearance: visual inspection. Porosity: ferroxyl test.
Applications
At Fulei Metal, we electroplate: fasteners and hardware, brackets, electrical components, food equipment, and decorative elements.
Environmental Considerations
Plating baths contain chemicals. Hexavalent chromium being phased out. Trivalent chromium alternatives. Wastewater treatment required. Compliance with environmental regulations.
Conclusion
Electroplating provides specific surface properties for sheet metal parts. At Fulei Metal, our plating capabilities ensure components meet functional and aesthetic requirements.