398
M. Malathi et al.
subjected to the various types of coatings like GN, plating, thermal spray, PVD and
so on. Electroplating process of NiP and NiP composite is attempted to improve the
wear and corrosion resistance property. The ultrafine SiC is used for co-deposition
of ceramic particles in the NiP bath. The homogeneity of the electroplating bath is
improved by keeping the cathode and anode in dunking mode. The incorporation
of composite material depends on the concentration of SiC and dunking cycles per
minute [4–6].
2 Experimental Procedure
Several grades of martensitic stainless steel and hardened & tempered steel grades
are used for piston ring application. The SAE9254 is one such grade popularly used
for plating application [7, 8]. The material composition is as given Table 1.
The electroplating bath composition [1] is as given Table 2.
The electroplating of NiP and NiP + SiC is dependent on parameters like temperature, time and current density. The concentration of phosphorus content selected as
medium phosphorus and SiC ceramic particle used is to improve the wear properties
of the piston ring. The rings are assembled in the form of mandrel as shown in Fig. 1.
The pretreatment processes are alkaline degreasing, buffing, vapour blasting, reverse
etching to improve the adhesion. The mandrel is then assembled in the specially
made fixture as given in Fig. 2a, b and plated.
To improve the incorporation of SiC, special fixture was made and placed in the
tank for electroplating as given in Fig. 2a, b.
Trial conducted is varying the current densities 10A, 5A, 3A and 1A keeping the
other parameters constant, temperature 70 ± 1 °C, time −1 h and dunking speed −50
Table 1 Material
composition of SAE 9254
Elements
Weight in %
Carbon
Silicon
Manganese
Phosphorus
Sulphur
Chromium
0.50–0.60
1.20–1.60
0.50–0.80
0.03 max.
0.03 max.
0.50–0.80
Table 2 Electroplating bath
composition
Chemical name
Weight in gms/lt
Nickel sulphate
Nickel chloride
Sodium lauryl sulphate
Orthophosphoric acid
Phosphorus acid
Silicon carbide (composite material)
150.00
45.00
0.25
40.00
6.00
(5, 50, 100)
M. Malathi et al.
subjected to the various types of coatings like GN, plating, thermal spray, PVD and
so on. Electroplating process of NiP and NiP composite is attempted to improve the
wear and corrosion resistance property. The ultrafine SiC is used for co-deposition
of ceramic particles in the NiP bath. The homogeneity of the electroplating bath is
improved by keeping the cathode and anode in dunking mode. The incorporation
of composite material depends on the concentration of SiC and dunking cycles per
minute [4–6].
2 Experimental Procedure
Several grades of martensitic stainless steel and hardened & tempered steel grades
are used for piston ring application. The SAE9254 is one such grade popularly used
for plating application [7, 8]. The material composition is as given Table 1.
The electroplating bath composition [1] is as given Table 2.
The electroplating of NiP and NiP + SiC is dependent on parameters like temperature, time and current density. The concentration of phosphorus content selected as
medium phosphorus and SiC ceramic particle used is to improve the wear properties
of the piston ring. The rings are assembled in the form of mandrel as shown in Fig. 1.
The pretreatment processes are alkaline degreasing, buffing, vapour blasting, reverse
etching to improve the adhesion. The mandrel is then assembled in the specially
made fixture as given in Fig. 2a, b and plated.
To improve the incorporation of SiC, special fixture was made and placed in the
tank for electroplating as given in Fig. 2a, b.
Trial conducted is varying the current densities 10A, 5A, 3A and 1A keeping the
other parameters constant, temperature 70 ± 1 °C, time −1 h and dunking speed −50
Table 1 Material
composition of SAE 9254
Elements
Weight in %
Carbon
Silicon
Manganese
Phosphorus
Sulphur
Chromium
0.50–0.60
1.20–1.60
0.50–0.80
0.03 max.
0.03 max.
0.50–0.80
Table 2 Electroplating bath
composition
Chemical name
Weight in gms/lt
Nickel sulphate
Nickel chloride
Sodium lauryl sulphate
Orthophosphoric acid
Phosphorus acid
Silicon carbide (composite material)
150.00
45.00
0.25
40.00
6.00
(5, 50, 100)