______ is a process of forming a thick oxide layer of aluminium.

The correct answer is Anodising.

Key Points

• Anodising is the process of forming a thick oxide layer of aluminum.
  • The process is called anodizing because the part to be treated forms the anode electrode of an electrolytic cell.
  • This aluminum oxide coat makes it resistant to further corrosion. 
  • It is also useful in architectural finishing.

Additional Information

• Ductility is the ability of a material to be drawn or plastically deformed without fracture.
  • The ductility of steel varies depending on the types and levels of alloying elements present.
• Galvanisation or galvanization (or galvanizing as it is most commonly called) is the process of applying a protective zinc coating to iron or steel, to prevent rusting.
  • The most common method is hot-dip galvanizing, in which steel sections are submerged in a bath of molten zinc.
• Corrosion is a natural process that converts a refined metal into a more chemically stable form such as oxide, hydroxide, carbonate, or sulfide.
  • It is the gradual destruction of materials (usually a metal) by chemical or electrochemical reactions with their environment.