Aluminium is a versatile and widely used metal with a myriad of applications across various industries. Known for its lightweight nature, corrosion resistance, and excellent conductivity, aluminium has become an indispensable material in modern society.

One of the most notable properties of aluminium is its low density, making it approximately one-third the density of steel. This characteristic makes aluminium ideal for applications where weight reduction is critical, such as in the aerospace and automotive industries. Its lightweight nature contributes to fuel efficiency in vehicles and allows for the construction of strong yet lightweight aircraft structures.

The formation of mill scales occurs when iron oxides on the surface of the metal react with oxygen in the air. This reaction produces a layer of iron oxide compounds, primarily magnetite (Fe3O4) and hematite (Fe2O3), which adhere to the surface of the steel or iron product. Mill scale typically appears as a dark, rough, and flaky coating on the surface of the metal, ranging in thickness from a few micrometres to several millimetres, depending on the duration and intensity of the rolling process.