[China Aluminum Industry Network] flatness profile effect:
When the profile plane is convex or concave, the profile will be flattened in the mechanical polishing and mechanical hard plate drawing process. This will lead to differences in the drawing thickness at different positions on the plane. The friction between the surface of the profile and the working belt and the internal of the profile. There are differences in the organization, resulting in differences in the corrosion rate of the profile in the oxidation process. After the oxidation is completed, the surface of the profile is prone to blackening. According to the experimental results, under the same conditions, when the flatness of the profile is small, there is a certain reduction in the probability of having a problem product compared to a product with a large flatness. In practice, the amount of drawing of the profile is minimized in the drawing process to ensure the drawing effect on the surface of the profile. .
Die work with influence:
From the test data, it can be seen that the change of the working belt of the mold has a great influence on this problem. When the working belt of the mold is cut to 3-5mm, the bad phenomenon is basically eliminated. Therefore, the main cause of the problem of determining the section is the long working time of the mold. Aluminum alloy in the work out of the stress mainly for the three-dimensional stress: the work of the friction, radial grain pressure stress, longitudinal grain see the compressive stress, when the mold work belt is too long along the working surface of the crystal grain long time The sawing work has friction, and there is a huge difference between the metal flow along the working belt surface and the center metal flow. The longer the working belt is, the larger the profile extrusion ratio is, the more obvious the difference is, and the metal flow velocity difference causes the metal structure on the profile surface. There is a difference in the internal metal structure. In severe cases, peeling occurs on the surface. In addition, inconsistency in the thickness of the surface peeling during the drawing process causes black annular defects after oxidation of the profile.