Introduction to the different heat treatment states of aluminium alloys

Introduction to the different heat treatment states of aluminium alloys

T1 - Cooled from forming temperature and naturally aged to a largely stable condition.

T2-Annealed condition (only for castings).

T3-Natural ageing after solution treatment.

T31-Solid solution treated cold work (1%) followed by natural ageing.

T36-Solid solution treated cold work (6%) followed by natural ageing.

T37 - Natural ageing after solid solution treatment cold work (7%), for alloy 2219.

T4 - Natural ageing after solid solution treatment.

T41 - Boiling water quenching after solution treatment.

T411 - Solid solution treatment followed by air cooling to room temperature, hardness between O and T6, low residual stress.

T42 - Natural ageing after solution treatment. User-processed, suitable for alloy 2024, slightly lower strength than T4.

T5 - Artificial ageing after cooling from forming temperature.

T6 - Artificial ageing after solution treatment.

T61 - T41 + artificial ageing.

T611-Solid solution treatment with boiling water quenching.

T62-Artificial ageing after solution treatment.

T7-Solid solution treatment followed by stabilisation. Improves dimensional stability, reduces residual stresses and improves corrosion resistance.

T72-Solid solution treatment followed by over-aging.

T73 - Solution treatment followed by graded ageing, lower strength than T6, significantly higher corrosion resistance.

T76-Solid solution treatment followed by graded aging.

T8 - Artificial ageing after solid solution treatment with cold work.

T81-Solid solution treatment followed by cold working and artificial ageing. To improve deformation and improve strength after solution treatment.

T86-Cold work after solution treatment (6%), artificial ageing.

T87-T37+artificial ageing.

T9 - Artificial ageing after solution treatment followed by cold working.

T10-Cooling from forming temperature, artificial ageing followed by cold working.

Tx51 - Tensile treatment to relieve residual stresses after solution treatment.