The operation of gravity casting is mainly a traditional casting process with sand as the main molding material. Most of its lifting sand molds are made by gravity casting. If there are special requirements, low-pressure casting and centrifugation can also be used. Casting. And the applicability of sand casting is very wide, no matter what size, complexity, number, etc. can use this process.
Gravity casting also needs to touch the mold. Traditional molds are made of wood, but there are many drawbacks, so they have been gradually eliminated. Replaced by aluminum alloy molds or resin molds with high dimensional accuracy and long service life, although the price is slightly increased, the effect is very good. Because each sand mold can only be used for pouring once, it is damaged after casting, so it needs to be re-cast, and the resulting work efficiency will be much lower; and the sand itself is soft and porous, so the size of the casting The accuracy will also decrease and the surface will look rough. But I believe that with the continuous advancement of technology, these deficiencies can be overcome, and the processed products will be more perfect.
In the process of gravity casting, the mold surface should be coated once every time it is poured. At the same time, the mold temperature must be cooled. In actual work, the mold is usually immersed in a paint tank (graphite water tank) to solve the above requirements. The role of graphite: graphite is a heat-resistant substance, which separates the high-temperature copper water from the mold to protect and extend the life of the mold; the graphite powder is very fine, which can increase the mobility of copper water and make the product easy to cast.
Aluminum alloy gravity casting has high density and good toughness of the raw material aluminum alloy during the production process, and has good wear resistance and heat treatment during use. Aluminum alloy gravity casting can effectively increase the strength of its products after heat treatment .
Aluminum alloy gravity casting castings have good compactness and can be cast to a certain extent. The casting temperature and cooling temperature need to be appropriate, so that it can reduce porosity and burrs and cracks to a certain extent, and reduce machining.
Aluminum alloy gravity casting has less casting process, 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 big advantage of the product during use is that the mold Can be used repeatedly.