The process of melting and liquefying metals is called casting.
Casting is the action and effect of melting or melting (melting and liquefying metals or other solid bodies, giving shape to the molten metal). The concept is also used to name the establishment where metals are melted .
The casting process usually consists of manufacturing parts by melting a material and placing it in a mold . There the molten material solidifies and takes the shape of the mold.
sand casting
The most common process is sand casting , which consists of placing a molten metal in a sand mold so that, once the metal has solidified, the mold can be broken and the cast piece removed. If the metal is very heavy (such as iron or lead), the mold is covered with a thick sheet.
During the manufacturing process of metal parts through sand casting, the following stages are observed:
* The sand is compacted surrounding the model in its box, for which it is necessary in principle to place all the semi-models on a table, so that they form the model tables , which ensure that the two parts of the mold fit perfectly. Currently it is possible to carry out this step with automatic instruments, such as tires or hydraulic pistons;
* the male is placed. When you want to make a hollow part, two cores (also known as cores ) are needed to prevent molten metal from seeping through the empty spaces. The material used to make the cores is a sand with greater resistance than that of the mold, since they must be manipulated to be placed in the latter;
* The molten material is poured into the mold using a pouring cup or sprue and various feeding channels, which must be eliminated when the piece has solidified. The vapors and gases that are generated throughout the process are eliminated through the permeable zone;
* The material cools and solidifies. This is a decisive phase, given that if the cooling period is too short, it is likely that mechanical stresses will be generated in the piece or that cracks will appear on its surface; On the other hand, if this stage extends longer than appropriate, productivity decreases;
* the mold is broken and the piece is removed, at which time it is also necessary to remove the sand from the core, which is recycled and used in the manufacture of other molds;
* During this stage, which is known as deburring , the burrs, the feed ducts and the mass of excess metal (riser) that remain at the junction of the two sides of the mold are removed;
* The piece is finished and any remains of sand that remain stuck are cleaned.
Casting allows you to create metal parts that take the shape of a mold.
an alloy
For metallurgy , cast iron is an alloy of iron and carbon where its content exceeds 2% and is usually below 7%.
Beyond iron and carbon, other alloying elements may be included, such as phosphorus, silicon, or sulfur.
Casting in electronics and printing
In the field of electronics , the notion of foundry (in English) indicates a manufacturing unit for integrated circuits (chip). The foundry is carried out in a controlled environment to avoid any disorder that alters the process.
The manufacturing of the chips is carried out from semiconductor wafers that must pass various stages (photolithography, recording, doping, diffusion and metallization).
In the field of printing , finally, the foundry is the set of all molds of a kind for printing .