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Lexar unveils the world's first SD cards made of 316 stainless steel
(www.techspot.com)
This is a most excellent place for technology news and articles.
Well considering that most of the SD cards I've had always died from foul play or physical destruction of some kind I think that armoring them is not without merit.
Obviously like all solid state media they do wear out over time, and their wear leveling isn't as good as an SSD which has a much more sophisticated controller with much more sophisticated wear leveling management.