The main casting process includes:
Metal smelting, model making, pouring solidification and demoulding cleaning. The main materials used for casting are cast steel, cast iron, cast nonferrous alloys (copper, aluminum, zinc, lead, etc.). The most commonly used casting method is sand casting, followed by special casting methods, such as metal mold casting, investment casting, gypsum casting, etc. Sand casting can be divided into clay sand mold, organic binder sand mold, resin self-hardening sand mold, lost foam, etc.
Investment casting:
Usually refers to making a pattern with fusible materials, coating the surface of the pattern with several layers of refractory materials to make a shell, and then melting the pattern and discharging the shell to obtain a casting without a parting surface. After high-temperature roasting, it can be filled with sand and poured. It is often called “lost wax casting”.
Die casting:
It is to use high pressure to press the molten metal into a precision metal mold cavity at high speed. The molten metal cools and solidifies under pressure to form a casting. The commonly used pressure for die casting is 4-500MPa, and the metal filling speed is 0.5-120m/s. Therefore, high pressure and high speed are the fundamental differences between die casting and other casting methods, and are also important characteristics.
Low-pressure casting: refers to the method of filling the mold with liquid metal under low pressure (0.06-0.15MPa) and crystallizing under pressure to form castings.
Sand casting:
A casting method for producing castings in sand molds. Steel, iron and most non-ferrous alloy castings can be obtained by sand casting.