Question

Why copper and aluminium are not used as heater element

Answer 1

Thia answers your question:

https://www.quora.com/Why-are-aluminium-and-copper-not-used-for-making-the-elements-of-an-electrical-heater

Answer 2

Answer:

The heat produced in an elecrical circuit is directly related to the resistance in the conductor and the current according to Joule's law. Aluminum and copper are very good conductors, with low resistivity and not very efficient at converting electrical energy to heat energy.