MICROSTRUCTURE AND MECHANICAL PROPERTIES OF Mo-MODIFIED Ti6Al4V SPUR GEAR

Abstract

In order to improve the performance of the Ti6Al4V (TC4) spur gear, a Mo surface modified layer is prepared by the plasma surface metallurgy technique. The element concentration, microstructure and elastoplastic properties are investigated with glow-discharge optical emission spectroscope (GDOES), scanning electron microscope, optical microscope (OM) and nanoindenter. Engaging with 41Cr4 steel gears, the wear resistances of the treated and untreated TC4 spur gears are evaluated through running-in and operation tests performed by a friction and wear tester under lubricated conditions. By finite element analysis, contact stress distributions in the TC4 and 41Cr4 spur gears pair are quantitatively determined. The results indicate that, being compact and uniform, the Mo-modified layer has higher hardness and retains relatively fine plasticity. The wear resistance of the treated TC4 spur gear is improved significantly.