Difference between exotic material and not exotic

[komatias]

You could say you have an exotic grade of aluminium as it is difficult to source or is used in special applications..making it ££££££. your descripotion of the material could be anything really. Your clients however will be saying they need e.g 7075 aluminium with min Yield strength and each batch tested and inspected and accompanied by material certs etc, etc etc.

Exotic alloys usually have special properties. Examples that spring to mind are stainless steels with nitrogen content, nickel alloys such as inconel, titanium, kovar, invar. Some people also class composite plastics such as carbon fille PEEK as an exotic.

it all comes down to your own definition