Role of Fe2O3 in Dry Sliding Wear of A Titanium Alloy and Formation of Tribo-Layers

Abstract:

Artificial tribo-layer containing Fe₂O₃ were induced to form at room temperature by supplying Fe₂O₃ nanoparticles and its mixtures with TiO₂ or MoS₂ onto the sliding interfaces of Ti6Al4V alloy and GCr15 steel. The role of Fe₂O₃, TiO₂ and MoS₂ on the sliding wear performance of Ti6Al4V alloy was respectively studied. The effect of the relative content of Fe₂O₃ in artificial tribo-layer on wear behavior and mechanism of Ti6Al4V alloy was also explored. Results showed that Ti6Al4V alloy indeed presented a terrible wear resistance, but it would be changed by the supplied particles. The wear rate of Ti6Al4V alloy was further accelerated by TiO₂, was slightly and inappreciably reduced by MoS₂, but was completely inhibited by Fe₂O₃. In the case of supplying TiO₂-rich or MoS₂-rich particles, they were agglomerated into the grooves or pits on worn surfaces, instead of forming a tribo-layer. For Fe₂O₃-rich particles, an artificial tribo-layer were noticed to form and cover the worn surfaces. It was confirmed that the improved elevated-temperature wear resistance of titanium alloy was attributed to the appearance of Fe₂O₃. As the particles of MoS₂+80wt.% Fe₂O₃ were supplied, the tribo-layer possessed both of the lubricating property of MoS₂ and the load-carrying ability from Fe₂O₃, which brought the best performance of friction and wear for Ti6Al4V alloy.