1. It will make the alloy structure in the die casting discontinuous;
2. Reduce the air tightness of the workpiece;
3. Die castings are easily corroded;
4. Reduce the strength and plasticity of die castings;
5. Die castings are prone to cracks;
6. The difficulty of later processing increases;
7. The scrap rate of die castings has increased;
8. Harmful impurities cannot pass through environmental protection.
