(1) Heating method of aluminum alloy cast rod
Aluminum alloy cast rods are heated using power frequency induction heating. The characteristics of this heating method are:
a. The heating time is short and can reach about 500℃ in 3 minutes;
b. The extrusion temperature is controlled accurately, and the error does not exceed ±3℃.
If the resistance furnace is used to heat slowly, the Mg2Si phase will precipitate, affecting the strengthening effect.
(2)Aluminum profile extrusion
The following factors have been changed to rationally formulate the extrusion process of 6082 alloy aluminum profiles.
1. 6082 alloy has high deformation resistance, so the casting rod temperature should be towards the upper limit (480-500℃);
2. The temperature of the aluminum extrusion die should also be high;
3. In order to prevent shrinkage or the involvement of bubbles, oxide scale, and impurities, the pressure residue should be left longer;
4. To completely dissolve the main strengthening phase Mg2Si in the alloy, the quenching temperature must be above 500℃. Therefore, the extrusion exit temperature of the profile should be controlled at 500-530℃;
5. 6082 aluminum alloy has high quenching sensitivity. The alloy contains Mn, which promotes the formation of intragranular intermetallic compounds and has a negative impact on the quenching performance. The quenching cooling intensity is required to be high and the cooling speed is fast, and the temperature must be quickly reduced to below 50℃ through water quenching;
6. After sawing the 6082 aluminum alloy profile, the frame should be protected at a certain distance and should not be discharged too densely.
