Technologies

Basic Approach

When selecting an alloy, take all of the following criteria into consideration: Strength, corrosion resistance, decorative appeal, and processability. Finding an alloy that fulfills all of these criteria is difficult. If there is no need to do so, it is recommended that you decide upon an order of priority for selection criteria.

1. General-purpose pure aluminium material

Pure aluminium sheets, known as 1100 or 1200, are used for various purposes. Both have a purity of at least 99.00%.
1100 has about 0.1% added Cu (copper), and is somewhat stronger than 1200, but has slightly inferior corrosion resistance due to the added copper.

2. Strength-focused approach

As a guideline, the following lists alloys in ascending order of general strength:
Pure aluminium (1000-series alloys) < Al-Mn series (3000-series alloys) < Al-Mg series (5000-series alloys) < Al-Mg-Si series (6000-series alloys) < Al-Cu series (2000-series alloys) < Al-Zn-Mg series (7000-series alloys).

Each of these representative alloys can be divided into the following types:

• - Al-Mn series 3003, 3004
• - Al-Mg series 5052, 5083
• - Al-Mg-Si series 6063, 6061, 6005C
• - Al-Cu series 2014, 2017, 2024
• - Al-Zn-Mg series 7003, 7204, 7075, 7050

Aluminium alloys are now available in a wider range of tensile strengths from 60 MPa (material 1080-O) to 590 MPa (7075-T6). Tensile strength can be selected according to purpose.
For structures mainly consisting of welds, start by considering material 5083.
For even stronger weld strength, consider either 7204 or 7003.
If corrosion resistance is not a concern, or if complete corrosion protection can be provided, you can use materials 2014-T6, 2017-T3, 2024-T4, and 7075-T6.

3. Corrosion-resistance-focused approach

Corrosion resistance varies considerably by usage environment, and often does not match the corrosion resistance measured in accelerated corrosion tests. For medication and food product containers, consider the pure-aluminium-series alloys 1100 and 1200.
If you require even greater corrosion resistance, consider even purer aluminium such as 1070 and 1080. For water resistance, 3003 is used for freshwater, and 5052 or 5083 is used for seawater.
Al-Mg alloys with high Mg content, Al-Cu-series alloys, and Al-Zn-Mg-series alloys require caution because stress corrosion cracking might occur depending on the conditions of use.

4. Processability-based approach

1100, 3003, and 3004 are generally used in draw operations for beer cans and the like.
2011 offers particularly good machinability for general cutting materials, although its corrosion resistance is quite inferior. Aluminium alloys are appealing in part because they enable the manufacture of shapes in a variety of cross-sectional shapes thanks to extrusion processing. Effective use of these cross-sectional shapes can help to reduce total cost.

5. Weldability-based approach

For MIG and TIG welding, pure Al series, Al-Mn series, Al-Mg series, and Al-Zn-series alloys that do not contain Cu give superior results.
When the importance of post-weld strength is emphasized, 7204 or 7003 is selected. When corrosion resistance takes priority, 5083 is used.
The strength of Al-Mg-Si-series alloys is diminished by welding.