visage vs human face

visage and human face both are nouns.

Word	Noun	Adjective	Verb	Adverb
visage	Yes	No	No	No
human face	Yes	No	No	No

As nouns, human face is a hypernym of visage; that is, human face is a word with a broader meaning than visage:

visage: the human face (`kisser' and `smiler' and `mug' are informal terms for `face' and `phiz' is British)
human face: the front of the human head from the forehead to the chin and ear to ear

Other hypernyms of visage include face.

visage (noun)	human face (noun)
the appearance conveyed by a person's face	the front of the human head from the forehead to the chin and ear to ear
the human face (`kisser' and `smiler' and `mug' are informal terms for `face' and `phiz' is British)