Wear Resistance of Mo-Implanted H13 Steel by a Metal Vapor Vacuum Arc Source

Pulsed molybdenum ion beams extracted from a metal vapor vacuum arc ion source at voltage of 25 kV or 48 kV were implanted into H13 steel with a high implantation dose of 5 x 10¹⁷ ions.cm^-2 and a time-averaged ion beam current density of about 300μA.cm^-2. We have investigated the steel implanted for wear resistance by an optical interference microscope and a pin-on-disc apparatus. The Rutherford backscattering spectroscopy demonstrated that rather low energy ions could penetrate quite deep into the substrates. It was observed by x-ray photoelectron spectroscopy and transmission electron microscopy that carbide of molybdenum appeared in the doped region. The results showed that dramatically improved wear resistance of H13 steel after molybdenum ion implantation at 48 kV was attributed to the development of Mo₂C precipitates in the doped zone and to the formation of the implantation affected zone below the doped zone.