alias vs also known as

alias is a noun but also known as is not a noun.

Word	Noun	Adjective	Verb	Adverb
alias	Yes	No	No	Yes
also known as	No	No	No	Yes

As adverbs, alias and also known as are synonyms defined as:

Other synonyms of alias include a.k.a..

alias (noun)	also known as (noun)
a name that has been assumed

alias (adverb)	also known as (adverb)
as known or named at another time or place	as known or named at another time or place