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

Table 10

Effect of solution pH variation on electroless nickel deposition.

Acid bath			Alkaline bath
pH	Deposition (g/mm^2)	Appearances	pH	Deposition (g/mm^2)	Appearances (quality)
5.0	0.000275	Metallic	9.0	0.000252	Flaky, metallic
5.1	0.000273	Metallic	9.5	0.000286	Metallic
5.2	0.000312	Metallic	10.0	0.000302	Metallic
5.3	0.000399	Nonmetallic,	10.1	0.000223	Poor, peeling
5.4	0.000421	Poor	10.2	0.000221	Poor
5.5	0.000443	Poor	10.3	0.000257	Flaky
6.0	0.000303	Very poor	10.4	0.000253	Metallic, peeling
6.5	0.000308	Very poor	10.5	0.000352	Metallic, bright
7.0	0.000334	Very poor	10.6	0.000229	Flaky, metallic
7.5	0.000361	Very poor	10.7	0.000376	Flaky, metallic
8.0	0.000325	Very poor`	11.0	0.000322	Metallic, flaky
8.5	0.000354	Poor	11.5	0.000343	Metallic, uniform