What is the purpose of alloying metals?

Alloying of metals can be done to

a. Prevent rust(corrosion)

Ex. Chromium and nickel added to iron to form stainless steel. The chromium can form an oxide layer that can prevent iron from oxidise(rust). Suitable to make fork, spoon, and others.

b. To make it harder (hard to shaped)

Ex. Carbon is added to Iron to form steel. Steel is very hard, however brittle also. Suitable to make bridge, cars body, pipe and etc.

Ex. Aluminium is very light but very malleable. When it is added with copper and magnesium, it form duralumin. It is very hard, withstand corrosion and light. Its suitable to make an airplane body.

c. To improve the appearance

A normal metal usually gets dull when it exposed to air, water and uv light in a long time. To create an attractive surface and look, metal such neckel and chromium were added. Ex. Nickel were added to copper to form an alloy named cpro-nickel such alloy were used to make coins attractive and shiny.