INCREASED ENDURANCE LIFETIME OF MOS2 COATING ON TI-6A1-4V BY SUBSTRATE-SURFACE-PRETREATMENT

IMPROVING THE WEAR-ENDURANCE-LIFETIMES OF SPUTTERED MOS2 ON TITANIUM (TI) ALLOYS REPRESENTS AN ENABLING TECHNOLOGY FOR THESE ALLOYS. RESEARCHERS ARE PRETREATING TI-6A1-4V SURFACES BY ELEVATED-TEMPERATURE-ION-IMPLANTATION AND REACTIVE-ION-BEAM-SPUTTER-DEPOSITION TO PRODUCE CERAMIC SURFACE LAYERS, WHICH WILL SIGNIFICANTLY (I.E., >2 ORDERS OF MAGNITUDE) IMPROVE THE WEAR-ENDURANCE-LIFETIMES OF SPUTTERED MOS2. CERAMIC LAYERS THAT EXHIBIT A RANGE OF ELECTRONIC (BAND GAP) PROPERTIES ARE FORMED ON TI-6A1-4V SUBSTRATE SURFACES. PRETREATED SUBSTRATE SURFACES ARE CHARACTERIZED BY X-RAY PHOTOELECTRON SPECTROSCOPY TO ESTABLISH THE BINDING ENERGIES/CHEMICAL STATES OF ELEMENTS IMPORTANT IN THE BONDING PROCESS. SCRATCH ADHESION TESTS ON THE MOS2/PRETREATED SUBSTRATES ARE BEING PERFORMED TO ESTABLISH THE THREE BEST PRETREATMENTS FOLLOWED BY WEAR-ENDURANCE-LIFETIMES TESTS IN AN ARGON ATMOSPHERE, ON SPECIMENS EXHIBITING THE GREATEST ADHESION. CORRELATIONS OF CERAMIC ELECTRONIC PROPERTIES WITH MOS2 TRIBOLOGICAL PERFORMANCE ARE BEING MADE. PREPARATION OF PRETREATED SUBSTRATES AND MECHANISM GEARS FOR COMMERCIAL COATING VENDORS TO APPLY THEIR SPECIFIC TRIBO-COATINGS IS A VIABLE PRODUCT. INCREASED USE OF TI GEARING IN MECHANISMS AND TRANSMISSIONS WILL RESULT IN REDUCED WEIGHT OF SPACE AND TERRESTRIAL VEHICLES AND INCREASED FUEL EFFICIENCY.