Gravity casting refers to the process of injecting molten metal into a mould under the effect of the earth's gravity, also known as casting. The molten metal is generally poured into the pouring gate using technology, and the product is obtained after filling the cavity, exhausting, cooling, and opening the mould by relying on the weight of the molten metal.
Gravity casting has the advantages of simple process, low mould cost, less internal pores, and available heat treatment, but at the same time it has the disadvantages of poor density and strength, not suitable for thin-walled parts, low surface finish, low production power, and high cost.
Die casting refers to the method of filling the die casting mould (die cast tooling) cavity with liquid or semi-liquid metal at a higher speed under the effect of high pressure, and moulding and condensing it under pressure to obtain zinc alloy die cast.
Die casting has the advantages of quickly filling the mould, high production power, fine product, high hardness and good surface finish, which is also suitable for the production of the parts with relatively thin wall thickness;
Because high-pressure air is used for filling, and there is more gas involved inside, it is easy to form pores inside the product, so heat treatment is not allowed (the internal gas will expand during heat treatment, which leads to defects such as bulging or cracking of the product). It is also not allowed to perform post-machining with excessive processing volume (to prevent penetrating the fine surface layer, exposing subcutaneous pores, and forming zinc alloy die castings to be scrapped).
CNC is commonly known as "numerical control machine tool", which is an automated machine tool controlled by a program. The control system can logically process programs with control codes or other symbolic instruction rules. Through computer decoding, the machine tool can execute the regular actions, and a piece of original metal sheet can be finely processed for a long time to form the desired shape. Plants for zinc alloy die casting are generally responsible for the rough machining of die cast tooling parts or the processing of zinc alloy die casting that requires high precision.