When determining the injection speed, the maximum speed should not exceed 100m/S. The speed is too high, which promotes the corrosion of the die-casting mold and the increase of deposits on the cavity and core; but too low is likely to cause defects in the casting. Therefore, the corresponding minimum injection speeds for magnesium, aluminum, and zinc are 27, 18, and 12m/s, the maximum injection speed of cast aluminum should not exceed 53m/s, and the average injection speed is 43m/s.

In the process of processing, thicker templates cannot be superimposed to ensure their thickness. Because the steel plate is twice as thick and the bending deformation is reduced by 85%, the lamination can only play a superposition. The bending deformation of the two boards with the same thickness as the veneer is 4 times that of the veneer. In addition, when processing the cooling water channel, special attention should be paid to ensure concentricity in the two-sided processing. If the head corners are not concentric with each other, the connected corners will crack during use. The surface of the cooling system should be smooth, preferably without machining marks. EDM is more and more widely used in mold cavity processing, but there is a hardened layer on the surface of the cavity after processing. This is due to the self-carburizing and quenching of the die-casting mold surface during processing. The thickness of the hardened layer is determined by the current intensity and frequency during processing. It is deeper during rough machining and shallower during finishing. Regardless of the depth, the mold surface has great stress. If the hardened layer is not removed or the stress is eliminated, cracks, pitting and cracks will occur on the surface of the mold during use.

①Remove the hardened layer with oil stone or grinding;

②Under the condition of not reducing the hardness, the stress is lowered below the tempering temperature, which can greatly reduce the surface stress of the cavity.

The casting process should be strictly controlled during the use of the mold. Within the scope of the process permit, try to reduce the casting temperature and injection speed of the molten aluminum, and increase the preheating temperature of the mold. The preheating temperature of the aluminum die-casting mold is increased from 100 to 130°C to 180 to 200°C, and the life of the mold can be greatly improved.