Gravity casting refers to the process of pouring molten metal into a mold under the action of the gravity of the earth, also known as gravity casting. In the broad sense, gravity casting includes sand casting, metal casting, investment casting, lost foam casting, mud casting, etc .; narrow gravity casting mainly refers to metal casting. Metal mold casting is a modern process for making hollow molds for casting with heat-resistant alloy steel.
Metal molds can be cast by gravity or pressure. The metal mold can be used repeatedly for many times. Every time the metal liquid is poured, a casting is obtained. The life is very long and the production efficiency is very high. Metal molds not only have good dimensional accuracy and smooth surface, but also have higher strength than sand molds when the same metal liquid is poured, and they are not easily damaged. Therefore, in the mass production of non-ferrous metal small and medium castings, as long as the melting point of the casting material is not too high, metal casting is generally preferred.
Metal casting also has some disadvantages: because heat-resistant alloy steel and the processing of hollow cavities on it are relatively expensive, the cost of metal molds is high, but the overall cost is much cheaper than the cost of die casting molds. . For small batch production, the cost of the mold allocated to each product is obviously too high and generally not easy to accept. And because the metal mold is limited by the size of the mold material and the capabilities of the cavity processing equipment and casting equipment, it can not help the particularly large castings. Therefore, in the production of small batches and large pieces, metal casting is rarely used.
In addition, although the metal mold uses heat-resistant alloy steel, its heat resistance is still limited. It is generally used for the casting of aluminum alloys, zinc alloys, and magnesium alloys. It has been less used in copper alloy castings and is used for ferrous metal castings. Even less. In the process of aluminum alloy gravity casting, the raw material aluminum alloy has high density and good toughness, and has good wear resistance and heat treatment during use. Aluminum alloy gravity casting can effectively improve the strength of its products after heat treatment. . Aluminum alloy gravity castings have good compactness and can be cast to a certain extent. The temperature and cooling temperature of the casting need to be appropriate. This can reduce pores and burrs and cracks to a certain extent, and reduce machining.
Aluminum alloy gravity casting has fewer casting processes, which can effectively reduce its production cost to a certain extent during use. The product is safe and environmentally friendly during the production process. The great advantage of the product during use is that The mold can be used repeatedly.