lost wax casting

Do you know the methods of extending the life of aluminum castings and the precautions in die casting?

Aluminum casting is a kind of parts made by pressure casting. It uses pressure casting machinery with investment casting molds to cast aluminum or aluminum alloy heated to liquid into the inlet of the aluminum casting. Die casting parts and then cast the castings you want. Aluminum castings are widely used in motorcycle manufacturing, electric motor manufacturing, automobile manufacturing, internal combustion engine production, oil pump manufacturing, landscaping, transmission machinery manufacturing, precision instruments, power construction, architectural decoration and other industries.

In the manufacturing process of aluminum castings, the formulation and execution of the die-casting process are closely related to the quality of the mold, die-casting equipment, and the operating technical level of the operators. Under the existing conditions of domestic die-casting equipment, it is difficult to achieve relatively stable, reliable and precise control of the parameters of the die-casting process. Realizing the basic control of the die-casting process is a process of combining and using die-casting equipment, die-casting materials, and molds. In the process of operation, the process and main parameters are not strictly implemented, and the shrinkage porosity, deformation, under-casting, and unqualified dimensions of aluminum alloy investment casting may also occur.

  • The following points should be done to extend the service life of aluminum castings:
    1. High-quality molding materials;
    2. Reasonably design mold wall thickness and other mold dimensions;
    3. Try to use inserts;
    4. Choose the largest possible turning angle R under possible conditions;
    5. The distance between the cooling water channel and the profile and corner must be large enough;
    6. After rough machining, stress tempering should be removed;
    7. Heat treatment is correct, and quenching and cooling must be fast enough;
    8. Thoroughly polish and remove the EDM scum layer;
    9. The profile surface cannot be highly polished;
    10. The mold surface should be oxidized;
    11. If selective nitriding, the infiltration layer should not be too deep;
    12. Preheat the mold to the recommended temperature in the correct way;
    13. Slow hammer speed should be used to start die-casting 5-10 pieces;
    14. On the premise of obtaining qualified products, try to reduce the temperature of the molten aluminum;
    15. Do not use too high polymetallic liquid injection speed;
    16. Ensure that the mold is properly cooled, and the temperature of the cooling water should be kept at 40~50℃;
    17. For temporary shutdown, try to close the mold and reduce the amount of cooling water to avoid thermal shock to the mold when restarting;
    18. The coolant should be turned off when the model surface is at the highest temperature;
    19. Do not spray too much release agent;
    20. Relieve stress and temper after a certain amount of die casting.
  • Matters needing attention in die casting process of aluminum investment casting:
    1. Appearance treatment and loading: After the aging of the blank, the hardness is qualified, the profile is not so simple and tortuous, but it is still necessary to pay attention to it when lifting the material at both ends, try to prevent vigorous shaking up and down, vigorous shaking will also affect the aged aluminum The profile forms a certain twist.
    2. Extrusion and framing: This link is also very important. After sawing the length of the aluminum profile, the aluminum profile must be framed. This fashion framer must pay attention to: whether the material is large or small, it is with tube The material is still drawn from the plane die. Generally speaking, large materials and materials with tubes are not easy to form twists and turns at the two ends of the frame, but small materials and materials drawn from a flat die can easily form twists when they are lifted. At this time, they should be lifted from the two ends to the center. Material loading frame. But some profiles are not even possible, such as shutters, windows, glands, etc., they must be placed on the aged profiles and then lifted into the frame.
    3. Extrusion and straightening: Straightening is a very serious part of profile formation. The straightener must pay attention to the strength used for straightening. If the strength is too strong, the profile may be deformed, closed, orange peel, etc., too little strength It will happen that the profile is not straight, forming twists and turns.

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