Difference Between Aluminum Plate Temper T5 and T6

6000 Series is Aluminium-Magnesium-Silicon Alloy. Its representative mark has 6061 Alloy, 6063 Alloy and 6082 Alloy. Different from other 7000 series aluminum alloy, 6000 Series aluminum plate is mainly in T temper, and the most used are T5 and T6.

What is Quench Ageing?

Ageing: The process of removing stress in a metal.

Quenching: Heating a metal to a certain high temperature and then suddenly cooling to a low temperature to achieve the desired hardness.

2000 series Alloy, 6000 series Alloy, and 7000 series Alloy can improve the strength by quenching.

T5: After extruding aluminum plate from the extruder, the temperature is rapidly reduced by air cooling to meet the required hardness (8 to 12 degrees Webster).

T6: After extruding aluminum plate from the extruder, then cooled by water to achieve higher hardness (over 13.5 Webster’s).

It takes a long time to cool down using air cooling, usually needs 2 to 3 days, which is called natural ageing. And the water cooling time is short, we call it artificial ageing. The main difference between T5 and T6 is in strength, the strength of T6 is higher than that of T5, and the performance in other aspects is similar. In terms of price, due to differences in the production process, aluminum plate T6 is slightly higher than T5.

What is Stress Relief Annealing?

During the production process, due to the heat and extrusion, the density between the crystals is not uniform, and the energy is not fully released and stored in the inner part, which is called internal stress.

The existence of internal stress will affect the next deep processing, such as bending, stretching, stamping, etc. If the internal stress is not released in advance, it will easily cause the bending of aluminum profiles, wave patterns and surface inequality.

The process of eliminating internal stress is very simple. After the aluminum plate goes down the assembly line, add a process, use the machine to stretch it, then release the energy inside.