It is well known that the shortcomings of zinc alloy die castings are caused by the current filling of the country. Because the temperature of the mold and the temperature of the alloy liquid are relatively low, the fine pits formed on the surface of the casting under the approximate underpressure condition are scattered. area.
Analysis on the Causes of Pock-ups in Zinc Alloy Die Castings
1. When filling, the metal scatters into dense droplets, which hit the shaped wall at high speed;
2. The thickness of the inner gate is too small;
3. The gate speed is too fast;
4. The mold temperature is low.
Corresponding methods to solve the pitting of zinc alloy die castings:
1. At the beginning of the hot mold, the molten metal flow will be found to be slack. Properly design the gating system to prevent molten metal from splashing, improve exhaust conditions, and prevent excessive gas from being drawn into the liquid flow;
2. At the beginning of the hot mold, the molten metal flow will be found to be erupting. Properly adjust the thickness of the inner gate;
3. At the beginning of the hot mold, the molten metal flow will be found to be erupting. Properly reduce the speed of the inner gate;
4. The appearance of the casting is dark and accompanied by a cold barrier. To increase the mold temperature to within the process requirements, the method is to turn on the mold heater or spray less and more hot molds.