This type of problem is often caused by a foreign object such as a popcorn seed being caught in the chopper blade area of the sump. You can
shut off the breaker
to the dishwasher and access this area by using the procedure in the image below. It is likely that you will find an object in the chopper blade area that is making the noise. Clear this area and reassemble the dishwasher.
If you do not find an item in this area or this does not fix the noise problem, then you could have a component failure that is causing the noise. I recommend calling a service technician to diagnose and repair that type of issue.
If you need more help, resubmit your question with additional details.