Can you give us a little more information on what you mean and what material information you need?
The material files (.mtl) are just text files formatted in a certain way that Creo understands. They contain naming and mass property information relative to a material. The system comes with some preinstalled files. By default, there is no material assigned to a part file.
Material name fields and density are the only ones that are used by the core Creo application.
PTC added the other fields back in the Wildfire days and have never done anything with them. I can see if you had a hardness that it would affect the results of a Mechanica analysis, but PTC has not linked all of that data together, that I am aware of.
