The key difference between steel and aluminium is that steel is an alloy whereas aluminium is a base metal for many alloys.
Steel and aluminium are materials that we see almost every day and almost everywhere. Aluminium is the third most abundant element in the world while steel is perhaps the most popular alloy. These two materials share similar applications but there are some differences between steel and aluminium as well.
What is Steel?
Steel is an alloy mainly formed from a mixture of iron and carbon; sometimes, other alloying elements are also used in steel production. Although human beings have known steel for around 4000 years, it was after the 17th century that it became commonly used because of more efficient means of production. Steel is very useful in construction, manufacture of appliances and vehicles.
The base metal for steel is iron. In its pure form, iron is soft and not useful as a construction material. Therefore, when alloying iron in order to produce steel, we add carbon in order to strengthen iron and convert it into steel. Adjusting the carbon content is the simplest way to change the mechanical properties of steel.
What is Aluminium?
Aluminium is a non-ferrous metal that is abundantly present in nature. Since it is highly reactive, it usually exists combined with over 270 different minerals, mainly bauxite compound. Furthermore, it is the third most abundant element in the earth’s crust.
Due to its resistance to corrosives and its low density, aluminium alloys are vital in the aerospace industry and are useful in transportation and building. Moreover, because of its reactive nature, aluminium is also used as a catalyst or an additive in explosives. A more common use of aluminium and one we see almost every day is packaging.
What is the Difference Between Steel and Aluminium?
Steel and aluminium are useful in a wide range of applications. Steel is an alloy while aluminium is an element. Hence, the key difference between steel and aluminium is that steel is an alloy whereas aluminium is a base metal for many alloys.
Moreover, we can identify certain differences between steel and aluminium in terms of properties and application too. Aluminium, unlike steel, is very reactive and whatever applications of aluminium we see now, it is usually mixed with other elements or compounds to prevent chemical reactions. Also, steel is very malleable in comparison to aluminium, while aluminium is lightweight. In car manufacturing, aluminium is considered better because it gives a better weight/strength ratio.
The below infographic summarizes the difference between steel and aluminium, comparatively.
Summary – Steel vs Aluminum
Steel is an alloy of iron and Aluminum is one of the most abundant elements on Earth and have many uses in the manufacturing and packaging industries. The key difference between steel and aluminium is that steel is an alloy whereas aluminium is a base metal for many alloys.
1. Wente, Edward F., et al. “Steel.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 10 Apr. 2019, Available here.
2. “Aluminium.” Wikipedia, Wikimedia Foundation, 30 Apr. 2019, Available here.