The purpose of heat treatment for aluminum profile castings is to improve mechanical properties, corrosion resistance, size stability, and machining properties such as cutting and welding. Because the mechanical properties of many as-cast aluminum alloy profiles cannot meet the application requirements,except AL-Si ZL102, AL-MG ZL302 and Al-Zn ZL401 alloy, the rest of the cast aluminum alloy profiles need to be heat-treated to further improve the mechanical properties and other properties of the castings.
Heat treatment state of profiles
State No. | Description and Application |
T0 | The condition of solution heat treatment, natural aging and then cold working. Suitable for the products whose strength is improved by cold working. |
T1 | Cooling by high temperature molding process, and then natural aging to the basic stable state. Suitable for products which are no longer cold processed after cooling by high temperature forming process. |
T2 | Cooled by high temperature forming process and aged to a basically stable state after cold processing. Suitable for cold working after cooling from high temperature forming process, or straightening and leveling to improve the strength of products. |
T3 | After solid solution heat treatment, it is cold worked and then aged to a basically stable state. Suitable for solution treatment, cold processing, or straightening, leveling to improve the strength of products. |
T4 | After solid solution heat treatment, it is aged naturally to a basically stable state. Suitable for solution heat treatment, no longer cold processing products. |
T5 | A state of being cooled by a high temperature molding process followed by artificial aging. Suitable for high temperature forming process after cooling, without cold processing, artificial aging products. |
T591 | The state of being cooled by a high temperature molding process followed by aging. |
T592 | The state of being cooled by a high temperature molding process followed by aging. |
T595 | The state of being cooled by a high temperature molding process followed by aging. |
T6 | The condition of artificial aging after solid solution heat treatment. Suitable for solution heat treatment, no longer cold processing products. |
T7 | The state of being over-aged after solid solution heat treatment. It is suitable for products whose strength exceeds the peak point on the aging curve during artificial aging in order to obtain some important characteristics after solid solution heat treatment. |
T8 | Solution heat treatment after cold processing, and then artificial aging state. Suitable for cold working, or straightening, leveling to improve the strength of products. |
T9 | The condition of artificial aging after solid solution heat treatment and then cold working. Suitable for the products whose strength is improved by cold working. |
T10 | Cooling by high temperature molding process, and then natural aging to the basic stable state. |
NOTED:
The difference between natural and artificial aging：
Natural aging -- a profile is strengthened by aging at room temperature for more than one month.
Artificial aging -- age-strengthening of a profile at temperatures higher than room temperature, such as 180 ° C.
