alloy

Preferred label: 

Substance having metallic properties, consisting of two or more metallic elements or of metallic and nonmetallic elements, which are miscible with each other when molten, and do not separate into distinct layers when solid.

AAT

The Arts and Architecture Thesaurus Online, The Getty Research Institute.

Additional reference: 
http://vocab.getty.edu/aat/300010902
Hierarchy: 
Broader concept: 
Top concept: 
materials
Getty AAT: