Effect of Processing Parameters on the Protective Quality of Electroless Nickel-Phosphorus on Cast Aluminium Alloy

Table 1

Pretreatment and EN plating chemicals.

Baths	Media	Volume (cm^3)	Concentration (g/L or mL/L)	Immersion time (min)
Rinsing	Water	1000	—	0.5–1.0
Emulsifying	Emulsifier: kerosene; + detergent solution	1000	15 ml; 15 g	0.5–1.0
Alkaline cleaning	Sodium hydroxide	1000	0.4 g	0.5–1.0
Acid cleaning	Hydrochloric acid	1000	5 mL	0.5–1.0
Surfactant	PCl2	1000	0.0–0.12 g	0.5–0.75
Plating	Nickel chloride		30 g
	Sodium hypophosphite		40 g
	Sodium citrate	3000–5000	25 g	1–10
	Ammonium chloride		50 g
	PCl2		0.02
Post plating	Antitarnish chemical: potassium-dichromate solution	1000	15 g	2-3

According to Winowlin Jappes [38].