Creo Simulate > Reference Links > Create a Material
  
Create a Material
Click File > New or click on the Materials dialog box to create a material.
A blank Material Definition dialog box appears on which you define the material properties. After you complete the definition and click Save To Model, the new material name appears on the Materials in Model list.
You can add a material to the model in the following ways:
Select a material from the library, and click .
Create a new material by using the File > New command or use on the Materials dialog box.
The material is listed in the Materials in Model list. Either method adds the new material to the database, but the material is not associated with any part or modeling entity until you assign it to the model. Note that you can move a material to the Materials in Library list from the model by selecting a material in the model and clicking . Creo Parametric prompts you to save the material as a file with a .mtl extension.