To achieve the maximum strength of alloys of the 6xxx group, the following sequence of heat treatments is applied:
- heating of aluminum during pressing until all particles are completely dissolved;
- hardening (rapid cooling (usually to the temperature of the production room, workshop);
- hardening by aging (due to the precipitation of hardening phases).
Strict temperature control during the entire production process allows to achieve the maximum mechanical properties of aluminum profiles.
There are the following types of state of the profile material (heat treatment) according to GOST):
Designation of the grade and condition of the profile material | Condition of profile material | Wall thickness or profile's shelf, mm | Ultimate resistance, MPa (kgf / mm2) | Yield strength, MPa (kgf /mm2) | Relative extension, % |
AD31 | Without heat treatment | All sizes | 78 (8) | - | 16 |
AD31T | Hardened and naturally aged | The same | 127 (13) | 69 (7) | 13 |
AD31T1 | Hardened and naturally aged | “ | 196 (20) | 147 (15) | 8 |
AD31T4 | Partially hardened and naturally aged | Up to 10 incl. | 108 (11) | 59 (6) | 15 |
АД31Т5 | Partially hardened and naturally aged | The same | 157 (16) | 118 (12) | 8 |
Comparison of the mechanical properties of the profiles at different heat treatments of the AD-31, 6060 and 6063 alloys.
Heat treatment type | Ultimate resistance, MPa | Yield strength, MPa | Relative extension, % | |
AD-31 Т5 | GOST | 157 | 118 | 8 |
Real | 190 | 150 | 13,5 | |
6060 Т5 | 140-160 | 100-120 | 8 | |
6063 Т5 | 160-175 | 110-130 | 7-8 | |
6060 Т64 | 180 | 120 | 12 | |
6063 Т64 | 180 | 120 | 12 | |
AD-31 Т1 | GOST | 196 | 147 | 8 |
Real | 210 | 180 | 12,5 | |
6060 Т6 | 170-190 | 140-150 | 8 | |
6063 Т6 | 195-215 | 160-170 | 8 | |
6060 Т66 | 195-215 | 150-160 | 8 | |
6063 Т66 | 225-245 | 180-200 | 8 |