Die casting is a manufacturing process used for forming metal parts by injecting molten metal into a die cavity at a very high pressure. Sound intimidating? It’s really not. Like any other technology, the die casting process comes with its own parameters that must be adhered to for successful molding. Below, we will review the most important parameters in die casting technology, and what role they play in the operation and performance of a die casting machine.
Clamping Force
The clamping force of a die casting machine is measured in either tons or kilonewtons (en), and is the amount of force the machine applies when the two clamps of the machine join together and the mold is clamped. Adjusting the clamping force can be used to account for part complexity, die wear, and die fill characteristics. More complicated parts and worn dies require higher clamping force, while a thicker die fill may need a lower clamping force. The optimal clamping force will naturally depend on the part being produced and the die it is being produced in. Reacting to these changes and finding the best clamping force setting is critical for ensuring the part quality and long-term die life.
Injection Pressure
For the die casting process to produce parts with the desired dimensional and structural qualities, the injection pressure needs to be accurately and consistently adjusted. This is the force of molten metal being injected into the die cavity. Generally, high injection pressure produces parts with excellent surface finish and fine surface details, while a lower injection pressure may help with flash reduction and reduce the likelihood of die locks. As with the clamping force, adjusting the injection pressure of a die casting machine is critical for producing parts of consistent quality.
Injection Velocity
The injection velocity is the speed at which metal is injected into the die cavity. A higher injection velocity means metal is injected into the die faster, where a lower injection velocity means metal is injected into the die more slowly. Setting the injection velocity is key to reducing die wear and eliminating metal losses while maintaining the dimensional accuracy of the part. Achieving the right balance between velocity and pressure is important to producing high-quality parts.
Injection Time
Injection time is the amount of time the metal is held under pressure in the die cavity before being evacuated. If the metal is evacuated too soon, the part can experience shrinkage and poor density, while if it is held for too long in the die cavity, the metal may cool down too fast and cause die locking. As with the other parameters, setting the injection time of a die casting machine correctly is important for reducing part defects and maintaining the quality of the parts produced.
The considerations for setting the parameters of a die casting machine correctly are as various as the parts being produced on it. The application of pressure, speed, and time are all key determinants of part quality. Keeping up with the die wear and part complexity, as well as choosing the optimal clamping force, injection pressure, velocity, and time all need to be carefully optimized for successful die casting. Understanding the fundamental principles of die casting technology, as well as the importance of monitoring and adjusting the parameters of the machine is key to producing durable and consistent die cast parts.
