Die casting is a metal mold pressure casting performed on a die casting machine, which is the most efficient casting process.
Die casting machines are divided into hot chamber die casting machines and cold chamber die casting machines. The hot chamber die casting machine has a high degree of automation, less material loss, and higher production efficiency than the cold chamber die casting machine. However, due to the heat resistance of the machine parts, it can only be used for the production of low melting point materials such as zinc alloy and magnesium alloy. Aluminum alloy die castings, which are widely used today, can only be produced on cold chamber die casting machines due to their high melting point. The main feature of die casting is that molten metal fills the cavity under high pressure and high speed, and forms and solidifies under high pressure. The disadvantage of die casting is: because the molten metal fills the cavity under high pressure and high speed, it is inevitable The air in the cavity is wrapped in the inside of the casting to form subcutaneous pores. Therefore, aluminum alloy die castings are not suitable for heat treatment, and zinc alloy die castings are not suitable for surface spraying (but painting). Otherwise, when the pores inside the casting are heated for the above treatment, they will expand due to heat and cause the casting to deform or bubble. In addition, the machining allowance of die castings should also be smaller, generally around 0.5mm, which can reduce the weight of the castings, reduce the amount of machining to reduce costs, and avoid penetrating the dense layer of the surface, exposing subcutaneous pores, causing The artifact is scrapped.
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