Precision Casting Equipment: Analysis of Low Pressure Casting Principle

The production process of precision casting equipment is diversified. Today, the editor will introduce the production process principle of low-pressure casting.

Low pressure casting is a casting method in which liquid alloy is pressed into the mold cavity from bottom to top under pressure, and solidifies under pressure to obtain castings. The principle of low-pressure casting is shown in Figure 1. Dry compressed air or inert gas is introduced into a sealed crucible, and with the help of the pressure acting on the metal liquid surface, the metal liquid is smoothly filled into the mold through the sprue from bottom to top along the riser. The filling pressure is generally 20-60kPa. After the casting is completely solidified, release the gas pressure on the liquid surface, so that the metal liquid that has not solidified in the riser and runner flows into the crucible by its own weight, and then open the mold to remove the casting.

The low-pressure casting production process includes the following four basic steps:

1) Metal smelting and preparation of molds or molds.

2) Preparation before pouring: including crucible sealing (assembly of sealing cover), scraping of slag in the riser, measurement of liquid level height, sealing test, mold fitting, fastening of mold or casting mold, etc.

3) Pouring: including liquid lifting, filling, pressurization, solidification, pressure relief, and cooling.

4) Demolding: including loose demolding and removal of castings.