Improvement of tribological performance by micro-arc oxidation treatment on selective laser melting Ti6Al4V alloy

The technique of Selective Laser Melting (SLM) has been widely applied as an additive manufacturing method in fabricating the Ti6Al4V parts. However, its relatively low wear resistance restricts the application of the SLM titanium alloy. In this paper, a promising way (Micro-arc Oxidation, MAO) was proposed to improve its wear resistance by forming a dense oxidized coating onto the SLM Ti6Al4V alloy surface. The dry sliding wear test and microhardness measurement were used to characterize the mechanical performance. It is found that with increasing treatment duration, coating growth was slowing down accompanied gradually roughening appearance. The oxidized layer was composed of gamma-alumina and TiAl2O5. Meanwhile, a significant improvement of tribology performance was found on the Ti6Al4V alloy by employing the MAO treatment. It can be believed that the MAO treatment can improve the reliability of the bearing surfaces on SLM Ti6Al4V parts.