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Nickel-Cadmium diffusion bake time

If the spec. requirement is to bake @630 °F for 1-2 hrs once parts have reached temperature, can a 5 hr. bake, once parts have reached temp., be too long? In other words can you have too much diffusion and would it be detrimental to the function of the finish.

Paul Doherty

2006

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2006

The OEM is the only one that can set parameters unless you have the FAA approved engineering staff to make such decisions.
It begs the question, why bake longer than is required?
It has been a long time since I did a microsection, but I doubt if a 5 hour bake is going to significantly increase the diffusion as the 2 hr bake gives nearly a 50% diffused layer. The further apart the two pure layers are, the slower the diffusion will be. Initially, they are touching.

James Watts
Navarre, Florida

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If the spec requires 1-2 hours, then 5 hours is too long because 5 fails to comply with the range 1-2.

Whether the 5 hour bake is harmful, not harmful, better, worse, or whatever, is irrelevant because the specification doesn't allow it to be done anyhow.

Bill Reynolds [deceased]
consultant metallurgist - Ballarat, Victoria, Australia
We sadly relate the news that Bill passed away on Jan. 29, 2010.
2006