When it starts in makes a noise like medal is rubbing until it gets to full speed then it stops and goes back to normal. This take 3-5 seconds. This is a tore 20 inch ecycler, i have had it about a year.

The first thing I would do is to look under the deck and see if the blade is hitting up against what I call a ring wall. This ring wall is in almost all mowers wether electric or gas. I believe it,s designed to keep the cut grass from clumping up under the deck and not discharging out the shoot. Sometimes grass, twigs, rocks, etc. get caught behind this wall PUSHING the wall out towards the blade. The blade in turn starts hitting the wall making the sound you are hearing.
First removed any grass from behind the wall, second take a hammer and tap the wall back to were it should be. Rotate the blade buy hand to see if their is clearance, if so you should be ready to mow again. GOOD LUCK.