Common defects and corresponding analysis of die-casting products

Update:11-05-2019
Summary:

1. The surface of the casting has a pattern and there a […]

1. The surface of the casting has a pattern and there are traces of metal flow.
Cause: The flow path to the inlet of the casting is too shallow; the injection pressure is too large, causing the metal flow rate to be too high, causing splashing of the molten metal. )
Adjustment method: deepen the gate flow path; reduce the injection specific pressure.
2. The surface of the casting has a small convex tumor
Cause: The surface is rough; the inner surface of the cavity has scratches or pits, and cracks are generated.
Adjustment method: polishing the cavity; replacing the cavity or repairing.
3. The surface of the casting has a putt impression, the surface is not smooth, rough
Cause: The pusher rod (jack) is too long; the cavity surface is rough, or there are debris.
Adjustment method: adjust the length of the push rod; polish the cavity to remove debris and oil.
4. There are cracks or local deformation on the surface of the casting.
Cause: The top rod is unevenly distributed or the quantity is not enough, and the force is uneven; the push rod fixing plate is deflected during work, causing one side to be stressed, one side is weak, and the product is deformed and cracked; the casting wall is too Thin, deformed after shrinkage.
Adjustment method: increase the number of ejector rods, adjust the distribution position, balance the casting force, and adjust and reinstall the push rod fixing plate.
5. There are air holes on the surface of the die casting
Cause: too much lubricant; the vent hole is blocked and the vent hole is not discharged.
Adjustment method: rational use of lubricant; addition and repair of venting holes, so that the exhaust is smooth.
6. The surface of the casting has shrinkage holes
Cause: The processability of the die casting is unreasonable, the wall thickness changes too much; the temperature of the molten metal is too high.
Adjustment method: in the wall thickness, increase the process hole to make it thin and even; reduce the temperature of the molten metal.
7. The outer contour of the casting is not clear, it can not be shaped, and the local material is not materialized.
Cause: The pressure of the die casting machine is not enough, the injection pressure is too low; the thickness of the inlet is too large; the position of the gate is not correct, causing a positive impact on the metal.
Adjustment method: replace the die-casting machine with larger compression ratio than the pressure; reduce the thickness of the feed port; change the position of the gate to prevent the impact on the front of the casting.
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