CEN Identification of Aluminium Alloys
Aluminium is the most widely used metal in engineering apart from iron. The reason the aluminium is widely used is because the combination of properties makes it one of the most versatile of engineering and construction materials. Aluminium is light in weight, yet some of its alloys have strengths greater than that of structural steel. It has good electrical and thermal conductivities and high reflectivity to both heat and light. It is highly corrosion resistant under a great many service conditions and is nontoxic. Aluminium can be cast,extruded forged, drawn, hot rolled and cold rolled.
The European numbering system (ref EN 573-1:1995 ) identifies the alloy using an identification starting with AW :
A for Aluminium and W for Wrought alloys ...(AB/AC for Cast Alloys-ref EN 1706 /BS EN 1780 ).
This is followed by number ranges for indicating groups of alloys.
Work Hardening Alloys
- En AW-1xxx Pure Aluminium (>99%)
- En AW-3xxx...Aluminium Manganese Alloys AlMn
- En AW-4xxx.. Aluminium Silicon Allosy AlSi
- En AW-5xxx..Aluminium-Magnesium alloys AlMg
Heat Treatable Alloys
- En AW-2xxxx Aluminium Cu alloys AlCu
- En AW-6xxx...Aluminium Magesium Silicon alloys AlMg Si
- En AW-7xxx.. Aluminium Zinc Magnesioum alloys AlZnMg
The alloy condition, or temper as covered in BS EN 515, is denoted by a suffix to the alloy code:
- O for Annealing
- F as fabricated,
- T for heat treatments.
(The T is followed be a number of digits identifying in some detail the heat treatment i.e. The first digit is a precise sequence of events. Subsequent digits: indicate a variation in treatment which significantly alters the characteristics of the product with respect to the original temper.
- H for Strain Hardened material supply.
(The H is followed be a number of digits i.e. ?First digit: type of treatment. ?Second digit: the final degree of strain-hardening, where 8 is normally the hardest (e.g. 4 = half hard). ?Third digit: (when used) a variation of a two-digit temper.)
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