What makes Aluminium welding unique?
Aluminium is probably the second most popular metal, due to its combination of light weight and relatively high strength. It is extremely versatile and with very good anti-corrosive properties, makes it an ideal metal for almost any industry. Aluminium is a non-ferrous metal (in other words it has no iron content), it is non-magnetic and has a number of properties that make welding very different from welding other steels.
These include:
ﾷ A low melting temperature
ﾷ Surface coating of Aluminium oxide
ﾷ High thermal expansion coefficient
ﾷ High thermal conductivity
ﾷ An absence of colour change at melting point
Aluminium also has all the normal metallurgical factors that apply to other metals.
Aluminum is an active metal and it reacts with oxygen in the air to produce a thin hard film of aluminum oxide on the surface. The melting point of aluminum oxide is approximately 1926`C, which is almost three times the melting point of pure aluminum, 660`C. In addition, this aluminum oxide film, particularly as it becomes thicker, will absorb moisture from the air.
Hydrogen in the form of moisture, oil, paint, and dirt in the weld area and even from the base metal itself are the main cause of weld porosity in Aluminium welding. With a rapid cooling rate, free hydrogen is retained within the weld and will cause porosity, which decreases weld strength and ductility. This also causes cracking and weakening of the weld. The aluminum oxide film must be removed prior to welding. This combined with the low melting temperature, makes aluminium more difficult to weld than other steels.
Aluminum conducts heat up to five times as fast as steel, which in turn requires that more heat must be put into the aluminum to work on it, even though the melting temperature of is less than half that of steel.
There are many different methods of welding aluminium, the most popular methods are MIG (Metal Inert Gas or GMAW - Gas Metal Arc Welding) and TIG (Tungsten Inert Gas or GTAW - Gas Tungsten Arc Welding). While the cost on these machines has decreased dramatically in recent years, using them requires some training and a reasonable amount of skill, which can only be achieved with lots of practice.
Not only does Durafix Easyweld, with its unique composition, make welding and repairing aluminium far easier than conventional processes, it also saves you both time and money.
Durafix Easyweld makes it possible for novice and professional to weld and repair almost any Aluminium, Al-alloy, Copper, Brass, Nickel, Pot-metal, White metal, Die cast Aluminium, Zinc, Kirksite and even Galvanized steel.
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