the definition of a bearing requires no moving parts. it describes a soft metal against harder metal. The soft metal wears instead of the component you are shielding from rotation.

what I am describing is the problem with your fancy 7000 series aluminum. It is the hardest of all the aluminums off the top of my head. So perhaps our silcon infused pistons are hard but what about its wearing specs? will the piston be the bearing? I suspect that's what you will get Sir!