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Electroless Nickel Plating-The Defects Seen Under Microscope

My customers recently required us to check our electroless nickel plated parts(base material is aluminium) under microscope of 30X, we seen a lot of problems like stain, black dots, porosity, pitted holes, white dots, etc. I would like to know, are all these are common defect of a electroless nickel plated part? if not, anyway to improve the plating quality to eliminate all these defects?

CHNG SENG KEONG
FABRICATION OF MECHANICAL COMPONENTS - PENANG, MALAYSIA
2005

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2005

An electroless nickel coating should not contain a significant amount of defects.

Those that you are seeing may be the result of defects in the aluminum substrate, especially if it is a casting. Electroless nickel will not cover up substrate defects. They are reproduced by the coating.

Ron Duncan [deceased]
- LaVergne, Tennessee
It is our sad duty to note Ron's passing on Dec. 15, 2006. A brief obituary opens Episode 13 of our Podcast.

Some EN deposits are plagued with all kind of defects, mostly home brew formulas. But even deposits from reputed houses may contain pits, like mid-phos formulas. pits and pores are deep and deleterious defects. Dots and stains normally are superficial only. Look for premium quality EN formulas and most surely your problems will disappear. But above all, never wait for a customer to force you analyze in depth what you are doing.

Guillermo Marrufo
Monterrey, NL, Mexico
2005