DRY FILM LUBRICANT FOR BEARINGS USING ION IMPLANTATION

HIGH SPEED CRYOGENIC TURBO-MACHINERY REQUIRES RELIABLE DRY FILM LUBRICANTS IN THE MAIN SHAFT TO SUPPORT THE ROLLINGELEMENT BEARINGS. THE LUBRICANT PRESENTLY USED HAS SHORT LIFETIME AND CAUSES UNACCEPTABLE WEAR RATE ON THE BEARINGS ONCE THE DRY FILMS ARE DEPLETED. NEW APPROACHES ARE REQUIRED FOR PROVIDING HIGHLY RELIABLE DRY FILM LUBRICANTS WHICH CAN SUBSTANTIALLY IMPROVE THE LUBRICANT LIFE IN THE LIQUID OXYGEN AND LIQUID HYDROGEN TURBO PUMPS. THE CONCEPT ADVANCED BY THIS PROJECT IS THE USE OF TECHNIQUES OF ION IMPLANTATION TO CREATE A SOFT LUBRICATION FILM OF MOS(2) IN THE NEAR SURFACE REGION OF THE BEARING MATERIALS. IT IS BELIEVED THAT THE EXISTENCE OF THE MOS(2) FILM REDUCES THE COEFFICIENT OF FRICTION AND WEAR RATE DRAMATICALLY. ION IMPLANTATION IN METALS HAS BEEN SHOWN TO IMPROVE THE WEAR RESISTANCE IN MANY METALS, EVEN AFTER THE IMPLANTED REGION WAS REMOVED. THIS EFFORT SEEKS TO DEMONSTRATE EXISTENCE ANDPERSISTENCE OF HIGHLY RELIABLE LUBRICATION FILMS ON THE BEARING MATERIALS.