Process control
Because is the greatest characteristic of 6082 aluminum alloy containing refractory metal Mn, Mn's moderate easy cause coring and solid-liquid zone plastic is reduced, cause the anti-cracking ability is insufficient, so the casting process should pay attention to the main three points: first, melting should pay attention to control the temperature between 740 ~ 760 ℃ and stir well, guarantee the accuracy of the metal melt completely, temperature, composition of uniform. Second, the casting should consider that the metal Mn increases the viscosity of the alloy, reduces its fluidity, and affects the casting performance of the alloy. The casting speed should be properly reduced and controlled in the range of 80~100mm/min. Third, increase the cooling intensity, speed up the cooling speed, aluminum profiles to eliminate the phenomenon of in-grain segregation. The primary cooling intensity was controlled and the secondary cooling intensity was increased to reduce the stress concentration during casting and avoid the ingot crack defects. The cooling water pressure should be controlled within the range of 0.1~0.3MPa.
Causes and treatment of aluminum profile processing without coloring:
1, anodic oxidation film thickness is insufficient. The solution is to check whether the anodic oxidation process is standard, 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 properly extended 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 sink for too long after oxidation. Timely dyeing is advocated. If this has happened, the workpiece can be placed in the anodic oxidation tank or the nitric acid neutralization tank for appropriate activation treatment 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, the oxidation temperature is too low, resulting in dense skin film. The oxidation temperature can be appropriately increased.
7. Poor conduction. May be anode copper rod or cathode lead plate contact poor batch conductivity shown. 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 bear 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 adopted to ensure the hardness of the mold under the premise of HRC48 ~ 52, with enough toughness. This is an important condition to prevent mold broken teeth.
