Bill Tindall, E.Tn.
The success of this adventure will depend on the substrate. What properties do you need from the substrate for it to work? This quest should start with this question. Should it be hard? Does it need to wear away and release new particles? What's critical? Once you know the properties a polymer can be chosen to provide them.

How do you expect to improve the result embedding abrasive on the surface by dispersing abrasive throughout the material? Embedded on the surface the abrasive is easily restored. If dispersed, worn abrasive rejection and new exposure must come from wearing away the matrix . That leads to alteration of surface geometry which leads to reflattening .