Ferrite core defect?

[homoly]

Hello,

I would like to ask you if the non homogeneous area with bids is normal in ferrite core manufacturing or it is a manufacturing defect:

http://www.box.net/shared/joea7pjmh9.

We have and issue of increased noise generation with this type of core from a certain supplier and I am curious if this could have effect on the problem.

Gabriel.

 

[MagMike]

I think it is normal. The features are probably related to the normal, uneven shrinkage that occurs during the sintering process.

How large is the part? A larger part is likely to have its cross-section cool at various rates.

 

[homoly]

Thanks Mike for the answer.

The cross section of the core is approx. 2 inches x 1 inch and the outer diameter of the core is something like 4 inches.