powder metallurgy vs metallurgy

powder metallurgy and metallurgy both are nouns.

Word	Noun	Adjective	Verb	Adverb
powder metallurgy	Yes	No	No	No
metallurgy	Yes	No	No	No

As nouns, metallurgy is a hypernym of powder metallurgy; that is, metallurgy is a word with a broader meaning than powder metallurgy:

powder metallurgy: the metallurgy of powdered metals; how to produce solid metal objects from powdered metal by compaction and sintering
metallurgy: the science and technology of metals

powder metallurgy (noun)	metallurgy (noun)
the metallurgy of powdered metals; how to produce solid metal objects from powdered metal by compaction and sintering	the science and technology of metals