What is the IUPAC nomenclature for Intermetallic Compounds?
In your example you have given two metals and a bond-indicating symbol.

Grammar

Hyphens, Plus and Minus Signs, 'em'Dashes and Bond Indicators

'em' Dashes (ALT+0151, 'en' dash would be ALT+0150)

a) Used to indicate metal–metal bonds in polynuclear compounds (e.g. "[Mn2(CO)10 bis(pentacarbonylmanganese)(Mn—Mn)").

b) Used to separate the indvidual constituents in names of (formal) addition compounds (e.g. "3CdSO4·8H2O cadmiumsulfate—water")

Alphabetical Order

a) Intermetallic compounds are sorted alphabetically within the group of cations and anions. Deviations are allowed in order to express structural information.

b) In coordination complexes, ligands are sorted alphabetically and the donating atom is put first (e.g. OH2 instead of H2O).

Further Reading

Therefore, I would write your example as "Co—Fe".

There are a lot more rules that you can read here: https://web.archive.org/web/20181005064417/https://www.iupac.org/fileadmin/user_upload/databases/Red_Book_2005.pdf