Aluminum is one of the most popular of materials used in the manufacture of cookware. Why is it so popular? Because of its ability to conduct heat so well. What this means to you is that foods are cooked evenly and hot spots on your cookware are reduced.
Bare aluminum can react with foods and being a soft metal can easily dent and scratch. You may also find that if you leave salty liquids in the pan for an extended period that pitting can occur. For this reason, most aluminum cookware today goes through a process of anodization which provides a strong durable product.
Aluminum is also commonly used in the manufacture of stainless steel cookware. As stainless steel is not a particularly good heat conductor, a layer of aluminum is often sandwiched between two layers of the stainless steel in the base of the pot or pan.
Read the full article here: The Art of Aluminum Cookware