Aluminium properties

With 8%, aluminium is the third most common element on earth after oxygen and silicon. Due to its low density of 2.7g / cm³, it has only a third of the weight of steel and is almost half as heavy as titanium. The weight of the different metals depends primarily on the alloy used. For carbon, the weight is mainly dependent on the resin mixture used.

Specific weight:

Steel:               7,5g – 8,5g / cm³

Titanium:         4,5g – 4,8g / cm³

Aluminium:      2,7g / cm³

Carbon:           1,5g / cm³

Aluminium alloys combined very many advantages. Compared to steel, aluminium is very light and at the same time very stable. It can be hardened and many high-strength alloys with specific properties are available. For many applications the strength is sufficient and due to the advantages aluminium is often the best material choice.

Further advantages are the insensitivity to temperature fluctuations, it is UV-resistant, corrosion-resistant, electrically conductive, hygienic and magnetically neutral. As a surface finish, aluminium can be powder-coated or anodised in almost all colours. Passivation is also possible, it has the advantage that the surface is electrically conductive. This is a very important property for many applications.

In the following table we compare the properties of aluminium and steel. For many properties, aluminium is better than steel. It must also be clearly stated that for some applications there is no way around steel.

Aluminium alloys have different specific properties that combine advantages and disadvantages. Depending on the application, it is recommended to use the right alloy to take advantage of the benefits.

Aluminium alloys mainly consist of the following elements:

• Magnesium (Mg)
• Silicon (Si)
• Manganese (Mn)
• Zinc (Zn)
• Copperr (Ku)

The different elements change the properties of aluminium alloys as follows.

In the following table you will find an overview of the different common aluminium alloys and their properties as far as machining is concerned. We have evaluated the topics forming, machining, welding, corrosion and anodising in a table.

In the following table you will find the physical properties of aluminium alloys clearly listed.

• Aluminium hardness in (Brinell)
• Aluminium tensile strength in (N/mm²)
• Aluminium yield strength in (N/mm²)
• Aluminium Thermal conductivity in (W/cm°C)    Conversion: 1 W/cm°C = 100 W/mk

7075 Alu is one of the many available alloys that deserves special mention. The field of application of 7075 Alu includes highly stressed constructions in aerospace and military applications. It is also known as aircraft aluminium. AW-7075 combines properties like: strength, stiffness, elasticity and corrosion resistance almost perfectly and is also very light.

There is a wide range of products made of this extraordinary material, including aluminium screws