metallographic sample vs sample

metallographic sample and sample both are nouns.

Word	Noun	Adjective	Verb	Adverb
metallographic sample	Yes	No	No	No
sample	Yes	No	Yes	No

As nouns, sample is a hypernym of metallographic sample; that is, sample is a word with a broader meaning than metallographic sample:

metallographic sample (noun)	sample (noun)
a sample of metal, carefully prepared for analysis.	a small part of something intended as representative of the whole
	items selected at random from a population and used to test hypotheses about the population
	all or part of a natural object that is collected and preserved as an example of its class

metallographic sample (verb)	sample (verb)
	take a sample of