Aluminium Alloys that are Best Suited for Welding
Aluminium like any other metal comes with its own unique physical and chemical properties. It is these properties which makes it suitable for various applications across industries. Most Aluminium used is in fact alloys of Aluminium, which means it is a combination of Aluminium with some other metal. It is these metals which are added to it that makes the properties of various alloys different and suitable for various applications. The properties of the alloys vary by grade.
Aluminium is suitable for many engineering applications primarily because it is lightweight. It is also less corrosive because it is a non ferrous metal and does not form rust. Aluminium welding however requires a lot of skill because it is more malleable than steel and occurrence of heat distortions are easier.
Alloys of Aluminium
Pure Aluminium being a soft metal, it is only by combining it with various other metals that its mechanical properties can be enhanced. It is according to the principal alloying elements used that these alloys are categorized into families using a four-digit identification system.
Let us examine the common families of aluminum alloys and their characteristics that render them weldable.
There are usually 7 different alloys used in the manufacturing of Aluminium. Each of these series are of four digits starting with and ranging between numbers 1-7. That number is what tells us what alloy element has been added to the aluminum.
The 7 series of them briefly are:
- 1000 Series is the purest of Aluminium and has a minimum of 99% aluminum and remaining are trace elements. It is weldable but only minimally. However due to its superior corrosion resistance and conductivity, it is mainly used in applications where it is required to carry electric current.
- 2000 Series is a high strength alloy of aluminum mixed with copper and is primarily used in aerospace applications. They are extremely sensitive to heat and not very weldable.
- 3000 Series is a medium strength alloy of Aluminium mixed with manganese and is very weldable, formable and can take heat treatment well. This aluminum alloy is often used in air conditioners, cookware and heat exchangers.
- 4000 Series is weldable and is an aluminum alloy with silicon. It has a lower melting point and is often used as filler material for welding and brazing.
- 5000 Series aluminum is a high strength alloy of Aluminium mixed with magnesium. It has a high degree of tensile strength and formability. Because of this it is widely used for heavy duty fabrication in the transportation and infrastructure industries.
- 6000 Series is Aluminium mixed with both magnesium and silicone as alloys and used largely in the form of extrusions and in structural components of the construction industry for angles, beams and tubes.
- 7000 Series is aluminum mixed with zinc as an alloy. It is a very high strength aluminum and is another series which is used in the aerospace industry as well as in sporting goods.
The weldability of Aluminium and its alloys is good when appropriate precautions are taken against porosity, solidification, liquidation cracking, profile imperfections in the weld bead etc. The most commonly used alloy series in Aluminium fabrication by Aluminium profile suppliers are usually 3000, 5000 or 6000. Aluminium extrusion process applied is an important factor in the quality of the end product of profiles.
KMC Aluminium, the Tamil Nadu Aluminium Company, counts among the leading Aluminium products manufacturers in India. It can also be considered the best Aluminium Company in Chennai in the industry of Aluminium extrusion profile manufacturers.