Reasons for local depression and smooth lines on aluminum die castings
Publish Time: 2024-07-10
Aluminum die castings can be made into various complex shapes, and can also be made with higher precision and finish, thus greatly reducing the amount of mechanical processing of castings and the casting allowance of metal copper, zinc, aluminum or aluminum alloy, which not only saves electricity, metal materials, but also greatly saves labor costs. Single pages have inevitable defects, and flow marks are one of them. Its characteristics are: the surface of the casting shows a local sunken smooth texture that is consistent with the flow direction of the molten metal, and can be felt by hand. This defect has no development direction and can be removed by polishing.
Causes:
1. Traces left by two metal flows filling the cavity asynchronously.
2. Low mold temperature, such as zinc alloy mold temperature below 150℃, aluminum alloy mold temperature below 180℃, are prone to such defects.
3. Filling speed is too high.
4. Excessive amount of paint.
Troubleshooting measures:
1. Adjust the cross-sectional area or position of the inner gate.
2. Adjust the mold temperature and increase the overflow groove.
3. Appropriately adjust the filling speed to change the flow pattern of the molten metal filling the cavity.
4. Apply the coating thinly and evenly.
