Corrosion and tribological performance of PTFE-coated electroless nickel boron coatings

- Electroless nickel boron (Ni-B) coatings are deposited on the mild steel substrate.
- Ni-B coatings show the coefficient of friction as low as < 0.1 after they are impregnated by an aqueous PTFE solution.
- The corrosion resistance of Ni-B coating on steel can be improved after PTFE impregnation.

Electroless nickel boron (Ni-B) coatings are finding their applications in the aerospace, automotive, chemical and electrical industries due to their properties such as high hardness and high wear resistance. However, Ni-B coatings generally show high friction. They also suffered from severe attacks in aqueous solution containing Cl− ion. In this paper, the experiments are carried out to reduce the friction and improve corrosion resistant properties of Ni-B coating by PTFE impregnation. It is found that Ni-B coating after impregnated by an aqueous solution containing 40 wt% PTFE nanoparticles is able to withstand a rubbing test duration of 3600 s with the coefficient of friction as low as < 0.1 under both dry sliding and lubricated by 3.5% NaCl solution. Additionally, the corrosion resistance of Ni-B coating on steel can be improved after PTFE impregnation.