For die casting, the three elements of die casting materials, die casting machines and moulds are indispensable. In the production process, the correct use of die-casting molds is very important due to improving production efficiency, brand quality and economic benefits, and extend the service life of die casting moulds.
During the die casting process, the die casting mould has been in a reciprocating fatigue state of thermal expansion and contraction. The temperature of the mould cavity has changed back and forth between 160 degrees and 350 degrees, causing fatigue damage to the mould. When the production is started in the cold mould state, the mould temperature starts to rise from low temperature, the temperature difference increases. Besides, the mould expansion and contraction increase, and its fatigue increases correspondingly, which will accelerate the mould damage and shorten its life. Therefore, continuous production should be as much as possible during die casting production to minimize the quick heating and cooling of the die casting mould, to extend the service life of the mould.
In addition, in the cold mould state, the die casting mould does not reach the temperature during normal production, and the gap between the mould parts is relatively large. In this case, it is strictly forbidden to turn on high-speed injection and pressurization. Otherwise, the aluminum skin will easily enter the gap of the mould, including the slider, the ejector pin hole, etc., which will damage the mould and affect its service life.
In the production of die casting, the injection speed not only affects the filling speed of the die casting and the injection gate speed, but at the same time, the high injection speed will increase the impact peak value. Therefore, the high injection speed and the high injection ingate speed will intensify the erosion of the die casting mould and increase the impact peak. In addition, they will increase the impact force that the mould bears, and the service life of the mould will be greatly reduced. Therefore, when we adjust the die casting process while ensuring the quality of the product, we try to reduce the injection speed as much as possible, which is very important for improving the life of the mould and the economic benefits of the die casting enterprise. At present, advanced die casting machines are equipped with injection brake devices, which are very beneficial to decrease the impact peak, reduce the impact force that the mould bears, and increase the service life of the mould.
In the production of die casting, we should not only pay attention to the injection speed but also the injecting pressure. Because the injecting pressure is not as easy to observe as the injection speed, it is often overlooked. In fact, it is an important parameter in the die casting process, which not only affects the quality of the casting but also has a huge impact on the service life of the die casting mould.
The pouring temperature of molten aluminum during die casting production not only affects the quality of the castings but also affects the service life of the die casting mould. In general die casting, the pouring temperature of molten aluminum is between 630℃ and 720℃. For different parts, we should choose a lower pouring temperature as much as possible, which not only saves energy but also prolongs the service life of the die casting mould. Because the higher the temperature of the aluminum liquid, the greater the erosion of the mould, the greater the range of the mold temperature field change. And the greater the thermal expansion and contraction, the greater the mold fatigue, the easier it is to damage. Therefore, appropriately lowering the pouring temperature of the molten aluminum is beneficial to prolong the service life of the die casting mould.