How to solve the defects on zinc alloy die castings-pitting? The defect phenomenon of zinc alloy die castings is the small pit-like distribution area formed on the surface of the casting under the under-layer because the mold temperature or the temperature of the alloy liquid is too low during the filling process.
The following is an analysis of the causes of pitting in zinc alloy die castings:
1. When filling, the metal is dispersed into dense droplets and hits 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 measures to solve the pitting of zinc alloy die castings:
1. When you start to iron the mold, you will find that the molten metal flow is dispersed. Properly design the gating system to avoid splashing of molten metal, improve exhaust conditions, and avoid excessive gas from being involved in the liquid flow;
2. When you start to iron the mold, you will find that the molten metal flow is sprayed. Properly adjust the thickness of the inner gate;
3. When you start to iron the mold, you will find that the molten metal flow is sprayed. Appropriately reduce the speed of the inner gate;
4. The surface of the casting is dark and accompanied by a cold barrier. 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.