Friction-induced construction of FeS-based lubricating coating and its tribological mechanism on 18CrNiMo7-6 steel

FeS self-lubricating coating was deposited on the surface of 18CrNiMo7-6 gear steel by electroless plating technique. The microscopic morphology, surface composition and tribological properties of the coatings were investigated. The results showed that the coating morphology consisted of micron-sized sheet or block structure accumulation. The main component of the coatings was FeS. After the tribological test, the worn surface of modified specimens was flat and smooth, while the uncoated specimens showed severe adhesive wear. At the later stage of the friction experiment, a portion of FeS was resynthesized under the action of friction heat to achieve a longer lubrication life. After surface modification, the FeS coating reflected better load carrying capacity and antifriction performance.