Effect of nano-LaF3 on the tribological behavior and corrosion resistance of bonded solid lubricating films

摘要

The friction and wear performances of bonded MoS2 solid lubricating films filled with lanthanum fluoride (LaF3) powders with the counterpart steel ball rubbing were investigated in fretting wear conditions. The corrosion resistance of the bonded lubricating films was evaluated according to GB/T 1771-91. Thus the effect of LaF3 nanopowders as filler on the wear resistance and corrosion resistance of the bonded lubricating films was highlighted. Experimental results show that the wear resistance of the bonded lubricating films increases with increasing content of LaF3 nanopowders within a content range between 0 and 5 wt.%, whereas the bonded lubricating films with 0.5-1 wt.% LaF3 micropowders exhibit the better wear-resistant ability. The incorporation of the LaF3 filler leads the increase of the coefficient of friction of the bonded lubricating films. Moreover, the incorporation of LaF3 can improve the corrosion resistance of the bonded lubricating films, whereas the incorporation of nano-LaF3 is more propitious to improve the corrosion resistance of the bonded lubricating films in a lower LaF3 content than micro-LaF3. The improvement in the wear resistance and corrosion resistance of the bonded lubricating films by the incorporation of the nano-LaF3 filler is attributed to the strengthened interfacial bonding among the nano-LaF3 and the MoS2 lubricant and the polymeric matrix. However, a too high mass fraction of the nano-LaF3 filler in the bonded lubricating films will increase surface and interface defects, and lead the worsening of corrosion resistance of the bonded lubricating films.