The causes of surface cracks of aluminum profiles are: (1) the extrusion coefficient of aluminum profiles is too large, the extrusion temperature is too high (bar, cylinder and die temperature), and the extrusion speed is too fast. (2): the extrusion force is unstable, high and low, or the speed difference between multi-speed regulation is obvious, and the speed conversion is sudden when shifting gears. (3): When aluminum alloy profile is extruded, the head end is pressed (punched) too fast, and the tail end runs at full speed or does not slow down, resulting in a large amount of aluminizing in the dead zone. (4): The quality of the rod is poor, the rod is burnt, and the grain is large and loose. The residue (V3 aluminum) is too thin. (V): The speed ratio of the extrusion die is seriously out of balance, and the design and manufacture are unreasonable.
Relevant measures for surface cracks of aluminum profiles: (1) Profiles with excessive extrusion coefficient can be produced on small machines with appropriate extrusion ratio; In addition, three extrusion temperatures should be strictly controlled according to the production process requirements, and appropriate extrusion speed should be adopted. (2): The operator should pay attention, adjust the speed smoothly, and the pressure should not be high or low, and cooperate with manual operation when shifting gears. (3): The front and rear ends of aluminum profiles are dead zones or V3 volume aluminum (aluminum rod surface), which has many impurities, poor quality and insufficient viscosity, so the extrusion speed of the front and rear ends of aluminum profiles should be slowed down. (4): The surface of aluminum bar should be fine, clean and free of oil stain, and the internal structure should meet the standards. Normal residual pressure (5% of the rod length) (5): The designer of extrusion die should design and manufacture a qualified die with uniform flow.
Related question and answer
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