How To Prevent Cracking Of Die-casting Molds?

1. Good casting structure design

The wall thickness of the casting is as uniform as possible to avoid the occurrence of thermal joints to reduce the thermal fatigue caused by the local heat concentration of the mold. Appropriate cast fillets should be placed at the corners of the casting to avoid stresses due to sharp corners on the mold.

2. Reasonable mold structure design

1) Each component in the mold should have sufficient rigidity and strength to withstand pressure without deformation. The mold wall thickness should be sufficient to reduce deformation.

2) The gating system is designed to minimize impact and erosion on the core.

3) Correctly select the tolerance fit and surface roughness of each component.

4) Maintain mold heat balance.

3. Specification of heat treatment process

The metallurgical structure of the material can be changed by heat treatment to ensure the necessary strength, hardness, dimensional stability at high temperatures, thermal fatigue resistance and material cutting performance.

The correct heat treatment process will result in optimum mold performance, while the properties of the steel are controlled by quenching temperature and time, cooling rate and tempering temperature.

4. Die casting production process control

1) Temperature control: preheating temperature and working temperature of the mold; alloy casting temperature, with a lower pouring temperature under the premise of ensuring good molding.

2) Reasonable die casting process: specific pressure and filling speed.

3) Adjust the clamping force of the machine to make the mold evenly stressed. Pay attention to cleaning the debris on the surface of the mold, so as to avoid the uneven force on the surface of the mold when the mold is closed, causing deformation.

4) Strict control of alloy smelting to reduce gas in molten metal.

5. Mold maintenance and maintenance

1) Regular stress relief

2) Mold repair