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What is the pretreatment for NiP coating on Al sheet by electroless method?

2006

I am doing NiP coating on Al sheet(commercial grade). I pretreated the substrate in SnCl2 and in PdCl2 respectively. But I got the coating dark/and sometimes bright but with dark patches. Is there any post-treatment which I should do?

Dhananjay Kumar

2006

To plate electroless nickel on aluminum requires a zincate preplate step (double zincate is better). No need for palladium or tin, that's for plastics.

Guillermo Marrufo

2006

That and a alkaline pH EN strike will really reduce the problems.

James Watts
Navarre, Florida

2006

I agree with Mr. Guillermo Marrufo. Double zincating is the recommended pretreatment for Al alloys before electroless plating.

T.S.N. Sankara Narayanan
- Chennai, Tamilnadu, India
(ed.note Nov. 2017: The good doctor has a fascinating blog at https://advancementinscience.wordpress.com)

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