Question

Give the composition and uses of Nichrome.

Answer 1

Hint: Nichrome is primarily composed of two substances. They both are well known metals. It is therefore an alloy.

Complete step by step solution:
Nichrome is an alloy mainly composed of nickel and chromium. Its most common form consists of 80$%$ nickel and 20$%$ chromium. It is chemically called as $NiCr$. Other types of nichrome contain varying concentration of the two elements. Iron is also a component of this alloy although it is a very small part in the total concentration. The chemical formula in this case becomes $NiFeCr$.

Some peculiar properties of nichrome are listed below:
- It has a high melting point.
- It is relatively more resistant to corrosion from moisture and other atmospheric effects than other metals and alloys unless there are specialized conditions
- Upon heating at high temperature the outer layer forms a covering of chromium oxide which acts as a shield to the inner layers and prevents further corrosion. For this reason unlike other metals and alloys nichrome is resistant to high heat.
- It is a bad conductor of electricity and therefore heats up very quickly when supplied with electric current.
- It remains ductile even after repeated uses without losing its nature.
- Unlike other metals used in heat producing devices, nichrome does not have to be drawn into thin wires to increase its resistivity as it is able to do so naturally which maintains its tensile strength and ensures longevity.
- It is non-magnetic at low temperatures which make it suitable to very specific industries.

Uses of nichrome:
- From its high resistivity it can be guessed that it is used in heat producing devices such as iron, toasters, hair dryer, electric ovens etc.
- It is highly used in fireworks and explosive industries.
- It is used to test the flame colour of cation fire.
- It is used in the ignition systems of rockets, electric matches and electronic cigarettes.
- It has a large number of uses inside factories which extract metals through the likes of blast furnaces and other systems which require high heat resistance.

Note: Although nichrome is composed mainly of nickel and chromium (as its name suggests) other metals such as iron and other elements are also used.
Nichrome is a bad conductor of electricity relative to other metals and alloys therefore its uses only include the phenomenon of heating due to electricity due to its high resistivity.