Effect of heat treatment on tribocorrosion behavior of amorphous and nanostructure Ni-P electroless coatings

In this study، the tribocorrosion behavior of nanostructure Ni-P electroless coatings in 3. 5 wt-% NaCl solution has been investigated. High phosphorus Ni-P coatings were deposited on mild steel by electroless plating and then they were isothermally heat treated at 400˚C (HT400) and 600˚C (HT600) for 1 h. The electrochemical behavior of the coatings was evaluated by potentiodynamic polarization technique in 3. 5 wt-% NaCl solution. Tribocorrosion tests were also done in 3. 5 wt-% NaCl solution. Scanning Electron Microscopy (SEM) and 3D profilometry were also used to study the wear scars. The results showed that the maximum tribocorrosion resistance and the lowest friction coefficient were obtained for heat treated Ni-P coating at 600˚C.