Process control
Because 6082 aluminum alloy is characterized by refractory metal Mn, the existence of the right amount of Mn is easy to cause intra crystalline segregation and the solid-liquid zone plastic reduction, resulting in insufficient cracking ability, so the melting casting process mainly needs to pay attention to three points: first, the melting should pay attention to the control temperature between 740~760℃ and stirring evenly, to ensure the metal melting, accurate temperature, uniform composition. Second, the casting should consider that Mn increases the viscosity of the alloy, reduces its fluidity, and affects the casting performance of the alloy. Casting speed should be properly reduced, controlled in the range of 80~100mm/min. Third, increase the cooling intensity, accelerate the cooling speed, aluminum profiles to eliminate the phenomenon of segregation in the crystal. The primary cooling intensity should be controlled and the secondary cooling intensity should be increased to reduce the stress concentration during casting and avoid the ingot crack defects. The cooling water pressure should be controlled within 0.1~0.3MPa.
Causes and treatment of aluminum profile processing without staining:
1. Insufficient anodic oxide film thickness. The solution is to check whether the anodic oxidation process is standardized, to see whether the temperature, voltage, conductivity and other factors are stable, if there is an anomaly, please adjust the specification accordingly, if there is no anomaly, can be appropriate to extend the oxidation time, to ensure the thickness of the film standard.
2. The PH value of the dye solution is too high. At this time, the PH value can be adjusted to the standard value by glacial acetic acid.
3. The workpiece is placed in the water tank for too long after oxidation. Timely dyeing is advocated. If this has happened, the workpiece can be properly activated in an anodic oxidation tank or a nitric acid neutralization tank before dyeing. The effect will be very good.
4. Improper selection of dyes. Appropriate dyes should be selected.
5, the dye has been decomposed or mildew, at this time need to replace the dye.
6, oxidation temperature is too low, resulting in dense skin film. The oxidation temperature can be appropriately raised.
7. Poor conduction. May anode copper rod or cathode lead plate contact poor as shown in batch conductivity. Pay attention to cleaning anode copper rod and cathode lead plate to ensure good conduction.
Because the mold of the radiator profile is many slender teeth, to withstand a lot of extrusion pressure, each tooth should have high strength and toughness, if there is a great difference between the performance of each other, it is easy to make the strength or toughness of those teeth fracture. Therefore, the quality of die steel must be reliable. It is best to use H13 steel produced by reliable manufacturers, or choose high-quality imported steel. The heat treatment of the die is very important, to use vacuum heating quenching, it is best to use high pressure pure nitrogen quenching, can ensure the uniform performance of each part of the die after quenching. After quenching, three times of tempering should be taken to ensure that the hardness of the die is HRC48 ~ 52 and has enough toughness. This is an important condition to prevent mold tooth breakage.
