Is this sentence correct? Could you please help me?

This process has been used to aggregate CNTs into metal matrices such as silicon, copper, aluminum and nickel.

It sounds ambiguous to me since I cannot tell by who, when or to what extent has this process been used. It may be correct, though. What do you think? How would you make it clearer?

The sentence is fine. It looks ambiguous because it has bern plucked from all context. I would normally expect either something before this sentence or after to fill in the details. Unless it's an actual quote, say in a marketing brochure from someone, in which case its normal to not expect much surrounding context.