sacrificial coating

Examples of sacrificial coating in the following topics:

• Preventing Corrosion

  • The process of coating a metal surface with another metal that is more likely to be oxidized is referred to as sacrificial coating.
  • Cathodic protection replicates the effects of a sacrificial coating but with a more active metal.
  • Using the same principle as sacrificial film coating, a sacrificial anode, made of a metal more active than the metal you want to protect, can be used to prevent corrosion on submerged or buried metal structures.
  • The sacrificial anode will corrode before the metal it is protecting does.
  • Galvanic sacrificial anode attached to the hull of a ship; here, the sacrificial anode shows corrosion but the metal it is attached to does not.

• Waxes

  • The leaves and fruits of many plants have waxy coatings, which may protect them from dehydration and small predators.
  • The feathers of birds and the fur of some animals have similar coatings which serve as a water repellent.

• Chemical Manufacturing

  • Products include electronic chemicals, industrial gases, adhesives and sealants as well as coatings, industrial and institutional cleaning chemicals, and catalysts.
  • Coatings make up about 15 percent of specialty chemicals sales, with other products ranging from 10 to 13 percent.

• Titanium, Chromium, and Manganese

  • Chromium oxide was used by the Chinese in the Qin dynasty over 2,000 years ago to coat metal weapons.
  • Weapons coated with chromium oxide were found with the Terracotta Army.

• Oxides

  • Even materials considered pure elements often develop an oxide coating.
  • As mentioned above, a well-known example is aluminum foil, which is coated with a thin film of aluminium oxide that passivates the metal, slowing further corrosion.

• Elemental Boron

  • Deficiency of boron in rats has been shown to result in poor coat or hair quality.

• Iron, Cobalt, Copper, Nickel, and Zinc

  • In galvanization, zinc coats iron by oxidizing to form a protective layer of zinc oxide (ZnO) that protects the iron from oxidation.

• Types of Synthetic Organic Polymers

  • PTFE is used as a non-stick coating for pans and other cookware because it has very low friction with other compounds.
  • Teflon (PTFE) is often used to coat non-stick frying pans as it is hydrophobic and possesses fairly high heat resistance.

• The Photoelectric Effect

  • Photomultipliers are extremely light-sensitive vacuum tubes with a photocathode coated onto part (an end or side) of the inside of the envelope.

• Properties of Phosphorus

  • The odor of combustion of this form has a characteristic garlic smell, and samples are commonly coated with white "(di)phosphorus pentoxide," which consists of P4O10 tetrahedra with oxygen inserted between the phosphorus atoms and at their vertices.