Fundamental Classification Knowledge on
Aluminium Alloy
Note: The essay adopts standard of ASTM ANSIH351-1978 which belong to international standard as IS (E107-1983E) in 1983, except special explanation.
1, Aluminium Alloy Classification: The entire wrought aluminium alloy can be classified into the following 8 kinds in the form of 4 digits code. The first number suggests the series of attribute.
1.1 The 1*** series aluminium alloy belong to industrial pure aluminium provided with characteristic of low density, sound conductivity and reflectance. Such kind of aluminium alloy could create compact and solid oxidation film in its surface which resists the erosion of oxygen. However, 1*** series alloy can not be strengthened via heat treatment only cold rigidification works. Consequently, the mechanism properties of 1*** alloy is not as high as another series.
1.2 The 2*** series aluminium alloy belong to heat treatment alloy containing CU as its main alloy element. Its trait is high intensity and nice fabrication capabilities but weaker anti-erosion performance. 2*** series alloy is widely used in aviation and space navigation due to its excellent properties of physical performance.
1.3 The 3*** series aluminium alloy belong to heat treat but non-rigidfication alloy. Its mechanism properties are better than 1*** because of its fine molding and sealing properties, meanwhile, 3*** series share the same anti-erosion properties of 1***. Accordingly, we can witness its comprehensively applied and considerable quantities of this medium intensity alloy. Mn is its sole alloy element.
1.4 The 4*** series aluminium alloy adopt Si as its main alloy element, most of such alloy belong to heat treatment non-rigidfication. The alloy containing 5% Si could present dark gray color after anodizing which used as machining decoration
accessory or architecture parts.
1.5 The 5*** series aluminium alloy adopt Mg as its main alloy element; belong to non heat treatment rigidfication alloy. And it is the lowest density alloy compared with others, but possess higher strength than 1*** and 3*** alloy, which belong to medium advanced intensity alloy. Moreover, this kinds of alloy has particular advantage in that its anti-marine and atmosphere erosion, which enable its marine and navigation application.
1.6 The 6*** series aluminium alloy adopt Mg and Si as its primary ingredient especially bestow the effective of mutual intensification of Mg2Si, belong to heat treatment and rigidfication alloy as 2*** series. Its internal attributes endow the alloy with higher intensity, sound seal joint and anti-erosion properties. It’s synthetical properties make the alloy become the best choice in architecture profile in the form of extruded products.
1.7 The 7*** series belong to heat treatment rigidfication alloy which employ Zn as its primary alloy element. The basic merits of the alloy consist in its excellent heat wrougnt properties and comprehensive quench range, especially, Al-Zn-Mg-Cu alloy is provided with most physical capabilities better than 2***, that’s the so-called super-rigid aluminium alloy with appropinquity between tensile strength and yield strength. 7*** series alloy is the most important structure material in aviation and spaceflight.
1.8 The 8*** series aluminium alloy adopt Li as its main accession element, share most the same properties with 1*** series, but possess better ductibility.
1.9 9***: Spare group.
2. Four kinds of fundamental temper
|
Code |
Name |
Illumination and Application |
|
F |
Free Fabrication Temper |
The products which carry special requirement of its machining rigidification and condition of heat-treatment during its moulding, and no regulation on its mechanism properties. |
|
O |
Anneal Temper |
The lowest hardness acquired by the products through complete anneal. |
|
H |
Machining Rigidification Temper |
To increase the hardness of products through machining rigidification, and the hardness of products could be decreased via extra heat-treatment,
(not necessarily). Two or three digits must be followed the code “H”. |
|
W |
Solution Heat-treatment Temper |
An unstable temper, which adopted only by some certain aluminium alloy products in its process of natural aging after solution heat-treatment. The code of the temper suggests that the products are in the process of natural aging only. |
|
T |
Heat-treatment (different from temper F,O,H) |
A stable quality which acquired (not necessarily) by machining rigidification after heat-treatment, and single or multiple digit must be followed the code “T”.
|
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