Aluminium is the most abundant metal on the Earth which makes it an ideal option for various applications
Along with its abundance, aluminium has the ability to be alloyed – a process that modifies a metal’s characteristic by mixing it with other metallic alloying elements. Alloying has enabled many grades of aluminium alloys with different characteristics to be formed. The different nature of the alloys will give a better understanding for the aluminium fabrication.
2. Aluminium Alloys
1XXX Alloys with 99.00% or higher purity has many applications, especially in the electrical and chemical fields. These grades are characterized by profound corrosion resistance, high thermal and electrical conductivities, weak mechanical properties, and excellent workability. Moderate increases in strength may be gained by strain hardening. Major impurities are iron and silicon.
Primary alloying material is copper in 2xxx series alloys, often with magnesium as a secondary addition. 2xxx series do not offer good corrosion resistance as most other alloys. Alloys in the 2xxx series are particularly applicable for parts and structures requiring high strength-to-weight ratios and are generally used to produce truck and aircraft wheels, truck suspension parts, aircraft fuselage and wing skins, structural parts, and those parts requiring good mechanical strength at high temperatures.
Manganese is the principal alloying material of 3xxx series alloys. 3xxx alloys are generally are non-heat-treatable but offer some 20% higher strength compared to 1xxx series alloys. Since only a limited percentage of manganese (up to about 1.5%) can be effectively mixed to aluminium, manganese is the primary element in only a few alloys. However, one of these, the 3003 alloy, is broadly considered as a general-purpose alloy for moderate-strength applications requiring good workability.
The principal alloying element in 4xxx series alloys is silicon, which can be mixed in sufficient quantities to cause substantial reducing of the melting range without causing brittleness. Therefore, these these alloys are used in welding wire for welding aluminium, where a lower melting range than that of the base metal is essential.
The principal alloying element in 5xxx series alloys is magnesium producing a moderate-to-high-strength alloy. Magnesium is more effective than manganese as a hardener and it can be added in considerably higher quantities. 5xxx alloys possess good welding characteristics and satisfactory resistance to corrosion in marine applications. However, certain constraints should be placed on the amount of cold work and the safe operating temperatures permissible for the higher-magnesium alloys to avoid stress-corrosion cracking.
6xxx series alloys contain silicon and magnesium for formation of magnesium silicide, making them heat treatable. Although not as strong as most 2xxx and 7xxx alloys, 6xxx series alloys have good formability, weldability, machinability, and corrosion resistance, with moderate strength.
Zinc, in amounts of between 1 and 8%, is the major alloying element in 7xxx series alloys. When mixed with a small amount of magnesium, heat-treatable alloys of moderate to very high strength will emerge. Generally other metals, such as copper and chromium, are added in small quantities. 7xxx series alloys are used in airframe structures, mobile equipment, and other parts which are exposed to high stresses.
Aluminium alloys are very popular materials for fabrication thanks to their superior formability, but it’s still very crucial to select the appropriate alloy for the appropriate task.
Aluminium fabricates are required to work with the right partners who have the experience and to qualify necessary raw material for a successful supply stream. Our article regarding the aluminium fabrication tips may also provide some insight to understand the nature of aluminium.