404
M. Malathi et al.
Fig. 8 Tafel plots of NiP composite-coated piston rings obtained for non-heat treated and heattreated conditions
3.5 Potentiodynamic Measurements
The polarization curves of Ni-medium P with SiC (5, 50 and 100 gms/lt) in the heat
treated and non-heat treated condition were measured on exposing the samples in
0.5 M Na 2 SO 4 solution is shown in Fig. 8. The corrosion data was compared with
conventional chrome-coated piston ring [1]. The corrosion potentials—Ecorr EC,
corrosion current densities—icorr CC and the Tafel line inclinations βa & βc and
corrosion rate mmpy are shown in Table 4.
From Table 4, the corrosion rate mm per year of heat-treated NiP composite plated
of concentration 5 g/lt is comparable with that of chrome-plated.
3.6 Wear Study
The wear study was conducted as shown in pin on disc TR10LE wear tester. The
weight loss is studied as a function heat-treated and non-heat-treated NiP compositecoated piston rings for SiC concentrations 5, 50 and 100 gm/lt. The wear testing
parameters are at an applied load of 50 N at 900 rpm for 15 min duration (Fig. 9).
The weight loss achieved for NiP med Phos + SiC 5g/lt is comparable with that
of chrome plating as shown in Table 5.
M. Malathi et al.
Fig. 8 Tafel plots of NiP composite-coated piston rings obtained for non-heat treated and heattreated conditions
3.5 Potentiodynamic Measurements
The polarization curves of Ni-medium P with SiC (5, 50 and 100 gms/lt) in the heat
treated and non-heat treated condition were measured on exposing the samples in
0.5 M Na 2 SO 4 solution is shown in Fig. 8. The corrosion data was compared with
conventional chrome-coated piston ring [1]. The corrosion potentials—Ecorr EC,
corrosion current densities—icorr CC and the Tafel line inclinations βa & βc and
corrosion rate mmpy are shown in Table 4.
From Table 4, the corrosion rate mm per year of heat-treated NiP composite plated
of concentration 5 g/lt is comparable with that of chrome-plated.
3.6 Wear Study
The wear study was conducted as shown in pin on disc TR10LE wear tester. The
weight loss is studied as a function heat-treated and non-heat-treated NiP compositecoated piston rings for SiC concentrations 5, 50 and 100 gm/lt. The wear testing
parameters are at an applied load of 50 N at 900 rpm for 15 min duration (Fig. 9).
The weight loss achieved for NiP med Phos + SiC 5g/lt is comparable with that
of chrome plating as shown in Table 5.