Metals: Surface Treatments

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Surface Treatments

Surface treatments are applied to metals to enhance their properties.

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  • Painting provides protection and improves the aesthetics of metals.
  • A layer of paint is applied to the metal surface.
    • The paint provides corrosion resistance.
    • The paint provides a desired colour or finish.
  • Primers can be used to improve adhesion.
  • Topcoats provide durability and weather resistance.
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  • Plating deposits a thin layer of metal onto the surface of a metal substrate.
  • Electroplating is a type of plating.
  • During electroplating, the metal substrate is immersed in an electrolyte solution with a metal salt.
    • An electric current is applied to deposit the desired metal onto the surface.
  • Common electroplating metals include chrome, nickel, zinc, and gold.
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  • Anodising is an electrochemical process.
  • Anodising is used on aluminium to create a durable and corrosion-resistant oxide layer on its surface.
    • The anodised layer can also be dyed to achieve various colours.
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  • Zinc coating is applied to steel or iron surfaces through a hot-dip galvanising process.
  • Galvanisation provides corrosion resistance.
  • Galvanisation is used for:
    • Structures.
    • Automotive components.
    • Fasteners.
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Powder coating

  • Powder coating involves applying a dry powder to a metal surface.
    • The metal surface is heated and cured to form a durable and protective coating.
  • Powder coating provides:
    • Corrosion resistance.
    • Impact resistance.
    • A range of colours and finishes.
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  • Passivation is a chemical process.
  • Passivation is used to improve the corrosion resistance of corrosion-resistant alloys.
    • For example, stainless steel.
  • Passivation involves treating the metal surface with an acid solution.
    • This process removes impurities and creates a passive oxide layer.

Jump to other topics

1Core Technical Principles

2Paper & Board: Specialist Technical Principles

3Timber: Specialist Technical Principles

4Metal: Specialist Technical Principles

5Polymers: Specialist Technical Principles

6Textiles: Specialist Technical Principles

7Designing & Making Principles

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