Friction and Wear Properties of Nano-Structured EN-PTFE-MoS2

By electroless nickel deposition, particle-free and composite nickel–phosphorus (NiP) coatings, which offer corrosion and wear protection to different substrates can be produced [1]. Low-alloy electroless nickel deposits are microcrystalline, that is, they consist of many very small grains. Values of 2 and 6 nm have been reported [2]. Materials so codeposited in composite deposition are either hard substances such as silicon carbide, aluminum oxide, etc. or dry lubricants such as PTFE, MoS2, and graphite. Lubricants affect tribological behavior by reducing friction [3]. Electroless composite coatings such as Ni-P-PTFE provide a low coefficient of friction. PTFE has a low useful load and should only be considered at low speed. As speed increases, load-cartying capacity decreases. Electroless Ni-P-PTFE cannot be used in heavy-duty applications. Thus it is necessary to employ a dry lubricant that can withstand high loads. MoS2 provides low shear strength and strong adhesion to the substrate material. MoS2 can withstand high loads over 10 times that of PTFE and also shows very long wear life. These characteristics have been measured in terms of the so-called filmability, which corresponds to the solid lubricant’s capability to deliver lubrication under load till seizure[4]. A lot of investigator have studied on influence of addition of each particle separately in Ni-P coating [4-6], but in this study we developed a multicomponent Ni-P-PTFE-MoS2 composite coating to combine the characters of both PTFE and MoS2 into one coating