tin plating corrosion
tin plating corrosion
(OP)
i have an aluminum block that is tin plated. starting to show signs of white corrosion. i have been told that it is normal for tin plating to show corrosion based on environmental conditions.
two questions:
1. can anyone confirm or deny that tin plating can corrode?
2. is there an easy test, i am thinking of some chemical that will change color in the presence of tin, that will just show if tin is present?
let me know if more details are necessary.
two questions:
1. can anyone confirm or deny that tin plating can corrode?
2. is there an easy test, i am thinking of some chemical that will change color in the presence of tin, that will just show if tin is present?
let me know if more details are necessary.





RE: tin plating corrosion
The white corrosion sounds more like the oxide that forms on aluminium.
desertfox
RE: tin plating corrosion
Normally the tin plating provides sacrificial corrosion protection of the base material, in your case the aluminium, after a period of time the tin plate cannot protect large area's of the exposed base metal and therefore the aluminium itself will start to corrode.
desertfox
RE: tin plating corrosion
Could you come back with more details of your application and environmental conditions seen by the part.
http://en.wikipedia.org/wiki/Tin_pest
RE: tin plating corrosion
the part size is about 5in x 5in.
all of your input is appreciated.
RE: tin plating corrosion
Any photo's of the part? It probably best to get it to a lab I would put my money on sacrificial corrosion but I can't rule out the "Tin Diease".
A picture may help
desertfox
RE: tin plating corrosion
RE: tin plating corrosion
I found this relating to "Tin Diease"
Tin Disease and History
The transformation of tin into its gray powdery allotrope has presumably occurred enough times in history to provide suitable examples for chemistry textbooks. Many of these accounts may be apocryphal. Many may simply be corrosion processes romanticized into bona fide cases of tin disease. (Tin by itself resists corrosion because of the oxide layer on its surface. If used to coat other metals, tin's corrosion-preventing properties become compromised when its surface is damaged. For example, the corrosion-prone steel of a "tin can" will quickly rust when its thin tin coat is punctured.) In any event, the following list may include valid illustrations of the temperature-dependant transformation of tin allotropes:
and the site it came from:-
ht
Thanks for the photo, well now I am beginning to thnk its "Tin Diease" after all, I'll see what else I can find.
desertfox
RE: tin plating corrosion
RE: tin plating corrosion