The principle of die casting technology is that molten metal is pressed into the cavity of precision metal mold at high speed by high pressure, and the molten metal is cooled and solidified under pressure to form castings. Cold chamber die-casting and hot chamber die-casting are two basic ways of die-casting technology, and their principles are shown in figure 1- 1. In cold chamber die casting, molten metal is poured into the pressure chamber by manual or automatic pouring device, and then the punch is pressed forward to press the metal into the cavity. In the hot chamber die casting process, the pressure chamber is vertical to the crucible, and the metal liquid automatically flows into the pressure chamber through the feed port on the pressure chamber. The injection punch moves downward and pushes the molten metal into the cavity through the gooseneck. After the molten metal solidifies, open the die casting mold and take out the casting to complete the die casting cycle.