Bimetal

Bi-metal refers to an object that is composed of two separate metals joined together. Instead of being a mixture of two or more metals, like alloys, bimetallic objects consist of layers of different metals. Trimetal and tetrametal refer to objects composed of three and four separate metals respectively.
See more at Wikipedia.org...

Noun
1. material made by bonding together sheets of two different metals
(hypernym) material, stuff
Adjective
1. formed of two different metals or alloys; especially in sheets bonded together
(synonym) bimetallic
(similar) metallic, metal(a)

Beverage containers with steel bodies and aluminum tops; handled differently from pure aluminum in recycling.

bimetal

bimetal