Aluminum vs. Steel
Weight to weight ratio
Aluminum is not as strong a material as steel, but being one-third its weight is the main reason it is used in aircraft construction.
Corrosion
It is made of iron, chromium, nickel, manganese and copper and has high resistance to corrosion, but aluminum can rust quickly in extremely acidic and basic environments because it has high oxidation and corrosion resistance.
Thermal Conductivity
Because aluminum has a much better thermal conductivity than steel, it is used in automobile radiators and air conditioning units.
Cost
Compared to stainless steel, aluminum has a more affordable price.
Machinability
Since aluminum is quite soft, it is easier to cut and shape. However, due to its resistance to abrasion, stainless steel has a harder structure, so working with these materials is more laborious and difficult than working with aluminum.
Source
Stainless steel is easier to weld than aluminum.
Thermal properties
Aluminum becomes very soft at about 400 degrees, while steel can be used at higher temperatures.
Electrical Conductivity
Stainless steel is a conductive material that is weak compared to most metals, but aluminum does a very good job of conductivity, so it is often used in high voltage power lines.
Strength
Stainless steel is stronger than Aluminum.
Effect on Food
Aluminum can cause a reaction in foods by affecting color and flavor, but stainless steel is a preferred material for use in the food industry because it is less reactive with food.