There are many variables in die casting that can influence the quality final product. These variables play an important role in the die casting process and they are:
Velocity of Molten Metal
The speed with which the molten metal is injected in to the die cavity is a very important factor. It is important for the molten metal to enter the cavity fully before the metal starts to solidify, that is, the molten metal should fill the cavity completely before the first part of the metal, which has already entered the cavity, starts to solidify. If the speed of the metal flow is not ideal, it will adversely affect the strength of the final product.
Injection Pressure
Injection pressure directly influences the speed of the molten metal entering the die cavity. Die casters will increase the injection pressure to have increased pressure tightness. They use a combination of high injection pressure and thick gating to offer structural stability to the casting, which will in turn improve the overall mechanical properties of the casting to offer castings with high tensile strength.
Gate Section
The time required for the molten metal to fill the cavity depends on the speed of metal at the gate and the area of the gate. If the gate is large, the injection speed can be low, but if the gate is small, the injection speed should be high for the cavity to be filled completely. The location of the gate also influences the quality of the final product, as the distance the molten metal need to travel to enter the die casting cavity depends on the position of the gate.
Die Casting Alloy
Some of the alloys used in die casting has better casting properties when compared to the other alloys. Solidification interval is an important factor that influences cast ability of an alloy. If difference between the solid point and liquid point of an alloy are high, it will be difficult to cast the alloy. Die casters use high pressures and faster injection speeds to cast such alloys.
Die Casting Die
The temperature of the die is another important casting variable. Molten metal that is injected to a cold mould will cool fast, which will lead to improper filling and poor surface finish of the final product. Furthermore, the die will be subjected to heat stresses that can negatively affect the life of the die. Factors like the metal temperature, volume of the casting, and the die size determines the temperature in which the die needs to be maintained.