Aluminum rivets are fine. No corrosion worry.

Why do Aluminium rivets corrode?

Corrosion develops when two dissimilar materials are combined in a corrosive electrolyte. This can occur when certain materials (such as aluminum) are in contact with stainless steel. However, there are ways to use stainless steel and aluminum together while preventing corrosion.

Is it OK to use aluminum rivets on steel?

For example, never place an aluminum rivet in a large piece of steel. When connecting two pieces of the same material, use a fastener/bolt made of the same material. For example, use an aluminum fastener when connecting two pieces of aluminum.