process control

Because 6082 aluminium alloy is characterized by the inclusion of refractory metal Mn, the proper amount of Mn can easily cause intragranular segregation and decrease the plasticity of solid-liquid zone, resulting in insufficient crack resistance, three points should be paid attention to in the melting process: first, the melting temperature should be controlled between 740-760 C and stirred evenly to ensure complete melting, accurate temperature and uniform composition of the metal. Secondly, it should be considered that Mn increases the viscosity of the alloy and decreases its fluidity, which affects its casting properties. The casting speed should be reduced appropriately and controlled in the range of 80-100 mm/min. Thirdly, increase the cooling intensity and speed up the cooling rate, so as to eliminate intragranular segregation. Controlling the primary cooling intensity and increasing the secondary cooling intensity can reduce the stress concentration and avoid the crack defect in the ingot. Cooling water pressure should be controlled in the range of 0.1-0.3 MPa.

Reasons and treatment of non-dyeing in aluminium profile processing:

1. The thickness of anodic oxide film is insufficient. 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 are abnormalities, please adjust the specifications accordingly. If there are no abnormalities, the oxidation time can be prolonged appropriately to ensure that the film thickness reaches the standard.

2. The PH value of dye solution is too high. At this time, the PH value can be adjusted to the standard value by glacial acetic acid.

3. After oxidation, the workpiece is placed in the tank for too long. Timely dyeing is advocated. If this happens, the workpiece can be dyed in an anodic oxidation tank or a nitric acid neutralization tank after proper activation.

4. Improper selecion of dyes. Suitable dyes should be selected.

5. The dyes have been decomposed or mildewed, and dyes need to be replaced at this time.

6. Low oxidation temperature results in dense skin film. The oxidation temperature can be increased appropriately.

7. Poor conductivity. Poor contact of anode copper rod or cathode lead plate may indicate poor bulk conductivity. Pay attention to cleaning anode copper rod and cathode lead plate to ensure good conductivity.

Because the radiator profile die is many slender teeth, to withstand a lot of extrusion force, each tooth must have a high strength and toughness, if the performance of each other is very different, it is easy to make those teeth with poor strength or toughness fracture. Therefore, the quality of die steel must be reliable, it is best to use H13 steel produced by reliable manufacturers, or selec high-quality imported steel. The heat treatment of the die is very important. To quench by vacuum heating, it is better to quench by high pressure pure nitrogen, which can ensure the uniform performance of all parts of the die after quenching. After quenching, three tempering steps should be taken to ensure that the hardness of the die is enough toughness under the premise of HRC 48-52. This is an important condition to prevent die teeth from breaking.