I did not take take a look inside the turbo. It was late last night. I will have to take the turbo off the car and look at it more thoroughly. I am thinking even if the fins rubbed against the housing, normally they should not take chips off of it. They should wear the housing or themselves more like a fine powder. That would be safer for the engine. But chunks that are about 1 mm aren't that good.
Anyways I'll look at it this week end and give more details.

Thanks